TY - JOUR AU - Ackermann, L. PY - 2006 TI - Air- and Moisture-Stable Secondary Phosphine Oxides as Preligands in Catalysis SP - 1557-71 KW - Phosphine oxides AB - A review. The application of secondary phosphine oxides to catalysis is reviewed. A survey of the literature up to summer 2005 is provided, covering the use of these air- and moisture-stable preligands in transformations catalyzed by transition-metal complexes and their use as precatalysts in nucleophilic catalysis. Their use in asym. catalysis, cross-coupling reactions and nucleophilic addn. reactions is discussed. JO - Synthesis ER - TY - JOUR AU - Albert, M. AU - Fensterbank, L. AU - Lacote, E. AU - Malacria, M. PY - 2006 TI - Tandem Radical Reactions SP - 1-62 KW - Radical reactions, tandem Tandem reactions, with radicals AB - A review. Radical tandem reactions-and in a wider context radical dominos or cascades-have attracted a lot of attention because of their intrinsic elegance and the construction of a broad and sometimes unique array of mol. architectures they allow in a single step. This review focuses on the latest progress in the design and development of new tandem reactions. The 1st part is devoted to intramol. processes; the 2nd part covers tandem and domino processes involving both intra- and intermol. steps. The 3rd part introduces intermol.-only reactions. Finally, the last part focuses on tandem reactions involving both radical and nonradical elementary steps. JO - Topics in Current Chemistry VL - 264 ER - TY - JOUR AU - Alkorta, I. AU - Picazo, O. AU - Elguero, J. PY - 2006 TI - Theoretical Studies on Chiral Discrimination SP - 695-714 KW - Chiral recognition AB - A review. This review summarizes a literature survey on chiral recognition as viewed from a theor. point. Nevertheless, exptl. results in the gas-phase are reported when they are relevant for the theor. calcns. The review is divided into the following sections: general considerations, expt. vs. theory; pure theor. results; solvent effects; metals as glue; optical rotatory power, and conclusions. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Andersen, O.A. AU - Dixon, M.J. AU - Eggleston, I.M. AU - van Aalten, D.M.F. PY - 2005 TI - Natural Product Family 18 Chitinase Inhibitors SP - 563-79 KW - Chitinase inhibitors AB - A review. This review covers the synthesis of natural product chitinase inhibitors and compares their binding modes with family 18 chitinases from a structural and kinetic viewpoint. JO - Natural Product Reports VL - 22 ER - TY - JOUR AU - Andrews, L. AU - Cho, H.-G. PY - 2006 TI - Matrix Preparation and Spectroscopic and Theoretical Investigations of Simple Methylidene and Methylidyne Complexes of Group 4-6 Transition Metals SP - 4040-53 KW - Methylidene complexes AB - A review. A new generation of simple methylidene complexes was prepd. by reactions of excited Group 4-6 transition metal atoms with Me halides and methane in solid Ar. These CH2:MHX (X = F, Cl, Br, I) and CH2:MH2 methylidene complexes exhibit agostic bonding effects of CH2 and MH2 distortion. The reactions proceed through the CH3-MX insertion product followed by ?-H transfer on an excited potential energy surface. The higher valence of Group 6 metals sustains a 2nd ?-H transfer to form the CH?MH2X (M = Mo, W, X = H, F, Cl, Br) methylidyne complexes, and electron capture by Group 5 CH2:MHX (M = Nb, Ta, X = H, F, Cl, Br) methylidene complexes gives rise to the analogous CH?MH2X- methylidyne anionic complexes. These simple organometallic complexes are identified by matrix IR spectra through isotopic substitution and by comparison with vibrational characteristics calcd. by DFT. Periodic trends in agostic interactions are illustrated for different metals and halogen substituents. Complementary studies for Group 3 and for Group 7-9 transition metals and for early lanthanide and actinide metals are also discussed and compared. JO - Organometallics VL - 25 ER - TY - JOUR AU - Asao, N. PY - 2006 TI - Gold- and Copper-Catalyzed [4+2] Benzannulations between Enynal or Enynone Units and 2.p.-Systems SP - 1645-56 KW - Benzannulation, with Au or Cu AB - A review. Gold-catalyzed formal [4+2] benzannulation between enynal or enynone units, including ortho-alkynyl(oxo)benzenes, and 2.p.-systems, such as alkynes and carbonyl compds. (enol forms) was reviewed. By simply changing the catalyst from gold to copper-Bronsted acid system, decarbonylated arom. compds. could be prepd. in the reactions using alkynes as the 2.p.-system. An efficient synthetic approach to angucyclinone antibiotics, (+)-ochromycinone and (+)-rubiginone B2, was developed by applying the present benzannulation to an intramol. version. The reaction proceeded most probably through the formation of the benzo[c]pyrylium ate complex via the intramol. nucleophilic addn. of the carbonyl oxygen atom to the alkyne part of enynal or enynone units, which was induced by carbophilic gold and copper catalysts. JO - Synlett ER - TY - JOUR AU - Ashfold, M.N.R. AU - Cronin, B. AU - Devine, A.L. AU - Dixon, R.N. AU - Nix, M.G.D. PY - 2006 TI - The Role of .p..s.* Excited States in the Photodissociation of Heteroaromatic Molecules SP - 1637-40 KW - Heteroaromatics, photolysis AB - High-resoln. measurements of the kinetic energies of hydrogen atom fragments formed during UV photolysis of imidazole, pyrrole, and phenol in the gas phase confirm that N(O)-H bond fission is an important nonradiative decay process from their resp. 1.p..s.* excited states. The measurements also reveal that the resp. cofragments (imidazolyl, pyrrolyl, and phenoxyl) are formed in very limited subsets of their available vibrational states. Identification of these product states yields uniquely detailed insights into the vibronic couplings involved in the photoinduced evolution from parent mol. to ultimate fragments. JO - Science VL - 312(5780) ER - TY - BOOK AU - Atta ur, R. AU - Ed PY - 2005 BT - Bioactive Natural Products (Part I). [In: Stud. Nat. Prod. Chem., 2005; 32] CY - Amsterdam, Netherlands PB - Elsevier SP - 1252 KW - Natural products, bioactive, book ER - TY - JOUR AU - Avalos, M. AU - Babiano, R. AU - Cintas, P. AU - Jimenez, J.L. AU - Palacios, J.C. PY - 2006 TI - Greener Media in Chemical Synthesis and Processing SP - 3904-8 KW - Green solvents, low-freezing AB - A review dealing with new green solvents. Upon mixing certain solids, a variety of low-freezing and biodegradable liqs. result. These eutectic mixts. offer a greener alternative to conventional ionic liqs. and org. solvents. For example, a low-freezing liq. results when choline chloride and urea are combined in a molar ratio of 1:2. The choline chloride/urea mixt. exhibits non-flammability and cond.; a eutectic mixt. of choline chloride and urea dissolves a wide range of transition metal oxides, a fact that could be exploited for industrial use such as in the recovery of metals from mineral ores. Ionic liqs. composed of choline chloride and zinc chloride in a molar ratio of 1:2 show interesting catalytic properties and can be recycled without decrease in activity : Diels-Alder cycloaddns. occur in this mixt. at room temp. JO - Angewandte Chemie, International Edition VL - 45 ER - TY - JOUR AU - Bandini, M. AU - Emer, E. AU - Tommasi, S. AU - Umani-Ronchi, A. PY - 2006 TI - Innovative Catalytic Protocols for the Ring-Closing Friedel-Crafts-Type Alkylation and Alkenylation of Arenes SP - 3527-44 KW - Aromatics, Friedel-Crafts alkylation AB - A review. Over the past years an astonishing no. of highly chemo- and regioselective intramol. Friedel-Crafts (FC)-type alkylations of arom. compds. were described in the literature that allow remarkable synthetic shortcuts for the prepn. of challenging arom. compds. In particular, both transition metal and conventional and unusual Lewis acids were described to promote ring-closing reactions even in the presence of Poly-functionalized cyclization precursors. Finally, the emerging field of catalytic enantioselective FC alkylations has recently concerned also intramol. transformations both in the presence of chiral org. and organometallic promoters. JO - European Journal of Organic Chemistry ER - TY - JOUR AU - Banwell, M.G. AU - Goodwin, T.E. AU - Ng, S. AU - Smith, J.A. AU - Wong, D.J. PY - 2006 TI - Palladium-Catalyzed Cross-Coupling and Related Reactions Involving Pyrroles SP - 3043-60 KW - Pyrroles, cross-coupling, Pd AB - A review. The Pd0-catalyzed cross-coupling of intact pyrroles with various reaction partners is reviewed. Coverage includes the Buchwald-Hartwig, carbonylation, Heck, Kumada, Negishi, Sonogashira, Stille, Suzuki-Miyaura, Tsuji-Trost, and (Pd0catalyzed) Ullmann reactions. Some emphasis is given to the application of such processes in the synthesis of pyrrole-contg. natural products. JO - European Journal of Organic Chemistry ER - TY - JOUR AU - Barbaro, P. PY - 2006 TI - Recycling Asymmetric Hydrogenation Catalysts by Their Immobilization Onto Ion-Exchange Resins SP - 5666-75 KW - Hydrogenation catalysts, asymmetric, immobilization AB - A review. Ion-exchange resins can be used as supports for the prepn. of single-site, heterogenized asym. hydrogenation catalysts. The immobilized catalysts obtained can be efficiently and conveniently recovered and recycled. This article reviews the significant contributions in the field including the main concepts behind the design and the applications of this type of catalyst. JO - Chemistry--A European Journal VL - 12 ER - TY - JOUR AU - Battiste, M.A. AU - Pelphrey, P.M. AU - Wright, D.L. PY - 2006 TI - The Cycloaddition Strategy for the Synthesis of Natural Products Containing Carbocyclic Seven-Membered Rings SP - 3438-47 KW - Carbocyles, 7-membered, synthesis AB - A review. Highly substituted carbocyclic seven-membered rings are frequently found in natural products and their synthesis represents a significant challenge to the synthetic chemist. Direct intramol. cyclization of these systems often proves difficult and this fact has catalyzed the development of a variety of strategies based on a convergent intermol. cycloaddn. strategy. This concept article discusses the major cycloaddn. approaches utilized to access these types of structures and primarily focuses on examples employed in the synthesis of natural products. JO - Chemistry--A European Journal VL - 12 ER - TY - JOUR AU - Bellina, F. AU - Rossi, R. PY - 2006 TI - Synthesis and Biological Activity of Pyrrole, Pyrroline and Pyrrolidine Derivatives with Two Aryl Groups on Adjacent Positions SP - 7213-56 KW - Pyrrole, diaryl Pyrroline, diaryl Pyrrolidine, diaryl AB - A review. The topics that are covered in the review include (i) the description of the structures and properties of biol. active natural and unnatural pyrrole derivs. with two aryl groups on adjacent positions; [ii] a crit. summary of the methods reported in the literature for the synthesis of 1,2-, 2,3- and 3,4-diaryl-1H-pyrroles, 1,2,3-(1,4,5-), 1,2,5-, 1,3,4-, 2,3,4-(3,4,5-) and 2,3,5-triaryl-1H-pyrroles, 1,2,3,5- and 2,3,4,5-tetraaryl-1H-pyrroles, 1,2,3,4,5-pentaaryl-1H-pyrroles and 2,3,3-triaryl-3H-pyrroles. Also included are (iii) a survey of the literature data on the biol. properties and the methods used to prep. 1-, 2- and 3-pyrrolines, pyrrolin-2-ones, 2,3-dihydropyrrole-2,3-diones, pyrrolidines, 2-pyrrolidinones, 3-hydroxy-3-pyrrolin-2-ones and pyrrolidine-2,4-diones with two aryl groups on adjacent positions; (iv) a description of the structures and biol. properties of naturally occurring sym. and unsym. 2,3-diarylmaleimides (3,4-diarylpyrrolidine-2,5-diones); and (v) a crit. summary of the methods designed and developed for prepg. sym. and unsym. 2,3-diarylmaleimides and 2,3-diarylsuccinimides (3,4-diarylpyrrolidine-2,5-diones). JO - Tetrahedron VL - 62 ER - TY - BOOK AU - Benoiton, N.L. AU - Ed PY - 2005 BT - Chemistry of Peptide Synthesis CY - Boca Raton, Florida PB - CRC Press SP - 304 KW - Peptide synthesis, book ER - TY - JOUR AU - Bhowmick, K.C. AU - Joshi, N.N. PY - 2006 TI - Syntheses and Applications of C2-Symmetric Chiral Diols SP - 1901-29 KW - Diols, chiral AB - A review. Synthetic procedures for a large variety of C 2-sym. chiral diols are reviewed. Prominent among these procedures are enantioselective redns., epoxide cleavages, dihydroxylation of olefins, and synthetic transformations. Applications of these diols as chiral auxiliaries/ligands for several important reactions are also highlighted. JO - Tetrahedron: Asymmetry VL - 17 ER - TY - JOUR AU - Binder, W.H. AU - Kluger, C. PY - 2006 TI - Azide/Alkyne-"Click" Reactions: Applications in Material Science and Organic Synthesis SP - 1791-815 KW - Sharpless click reactions AB - A review. The fixation of ligands onto mols., surfaces and materials using reactions using a simple and unified chem. is among the everlasting desires of chemists. Besides the general insensitivity with respect to the chem. structures of the ligand, the completeness of the reaction as well as the insensitivity from external reaction parameters (i.e.: solvents, ambient temp.) is required. The Cu(I)-catalyzed azide/alkyne click-reaction (also termed Sharpless click-reaction, a variation of the Huisgen 1,3-dipolar cycloaddn. reaction between terminal acetylenes and azides) is a recent re-discovery of a reaction fulfilling these requirements. Extremely high yields (usually >95 %) are combined with a high tolerance of functional groups and reactions running at moderate temps. (25° - 70°). The present review assembles recent literature for applications of these reactions in the field of material science, in particular on surfaces, polymers, and for the ligation of ligands to larger biomols., including own publications in this field. Since this is an extremely fast developing area, this review offers JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Bitterwolf, T.E. PY - 2006 TI - Annual Review of Organometallic and Nitrosyl Photochemistry: 2003 SP - 388-413 KW - Photochemistry, organometallic Photochemistry, nitrosyl AB - A review of the literature of organometallic and nitrosyl photochem. for 2003 was reviewed. JO - Coordination Chemistry Reviews VL - 250 ER - TY - JOUR AU - Blaser, H.-U. PY - 2006 TI - A Golden Boost to an Old Reaction SP - 312-13 KW - Aniline synthesis, Au catalysts AB - A review. Gold catalysts promote selective redn. of arom. nitro compds. to anilines, providing a new way to synthesize industrially important products. JO - Science VL - 313(5785) ER - TY - BOOK AU - Bond, G.C. PY - 2005 BT - Metal-Catalysed Reactions of Hydrocarbons CY - Berlin, Germany PB - Springer SP - 450 KW - Metal catalysis, of hydrocarbons, book ER - TY - JOUR AU - Braga, A.L. AU - Ludtke, D.S. AU - Vargas, F. AU - Braga, R.C. PY - 2006 TI - Catalytic Applications of Chiral Organoselenium Compounds in Asymmetric Synthesis SP - 1453-66 KW - Organoselenium compounds, chiral AB - A review of chiral Se-contg. compds. which have found a growing application in asym. catalysis over the past few years. The large majority of these ligands are derived from readily available chiral amino alcs. in a few high-yielding synthetic steps. The advantages of using these compds. are described, particularly those regarding ready accessibility, modular nature, formation of strong bonds with soft metals and more rarely with hard ones. By using an appropriate electrophilic or nucleophilic organoselenium fragment, novel chiral organoselenium catalysts or ligands were designed from chiral aziridines, oxazolines, ferrocenes, etc. High regioselectivity and enantioselectivity were achieved through the four following techniques: the enantioselective Cu-catalyzed conjugate addn. of organometallic reagents to enones, the diorganozinc addn. to aldehydes, Pd-catalyzed enantioselective allylic alkylation and asym. hydrosilylation or transfer hydrogenations of ketones. JO - Synlett ER - TY - JOUR AU - Brahma, S. PY - 2006 TI - Trans-Dichloro-bis(Benzonitrile)Palladium(II): A Versatile Reagent in Organic Synthesis SP - 1449-50 KW - Dichloropalladium, trans-bis(benzonitrile) AB - A brief review is given on the utility of trans- bis(benzonitrile)dichloropalladium as reactant and catalyst in org. synthesis. JO - Synlett ER - TY - JOUR AU - Bruneau, C. AU - Renaud, J.-L. AU - Demerseman, B. PY - 2006 TI - Pentamethylcyclopentadienyl-Ruthenium Catalysts for Regio- and Enantioselective Allylation of Nucleophiles SP - 5178-87 KW - Ruthenium complexes, cationic Nucleophiles, allylation AB - A review. Ruthenium(II) complexes contg. the pentamethylcyclopentadienyl ligand efficiently perform the activation of allylic carbonates and halides to generate cationic and dicationic ruthenium(IV) complexes. This activation has been transferred as a key step to the catalytic allylation of nucleophiles. The structural and electronic properties of the allylic moieties lead to the regioselective formation of chiral products resulting from nucleophilic addn. to their most substituted terminus. The catalytic activity of various Ru(Cp*) precatalysts in several allylic substitutions by C and O nucleophiles will be presented. The enantioselective version that has been demonstrated by using optically pure bisoxazoline ligands will also be discussed. JO - Chemistry--A European Journal VL - 12 ER - TY - JOUR AU - Bubnov, Y.N. AU - Kuznetsov, N.Y. AU - Gurskii, M.E. AU - Semenova, A.L. AU - Kolomnikova, G.D. AU - Potapova, T.V. PY - 2006 TI - Construction of Nitrogen Bicyclic and Cage Compounds with the Use of Allylic Organoboranes SP - 1357-68 KW - Organoboranes, N-bicyclics Cage compounds, N- AB - A review of the reactions of triallylborane with pyrrole, pyridines, isoquinolines, lactams, 1-pyrroline, and acetylenes offers versatile methodol. for the construction of various bicyclic and polycyclic N compds., some of which are skeletally related to important classes of alkaloids. Optically active 3-borabicyclo[3.3.1]non-6-enes are useful precursors for synthesis of chiral 3-aza- and 3-thiabicyclo[3.3.1]non-6- enes, as well as derived chiral cyclohexenoid systems. The convenient methodol. for the transformation of 1-boraadamantanes into 1-azaadamantanes is also discussed. JO - Pure and Applied Chemistry VL - 78 ER - TY - JOUR AU - Burstein, C. AU - Tschan, S. AU - Xie, X. AU - Glorius, F. PY - 2006 TI - N-Heterocyclic Carbene-Catalyzed Conjugate Umpolung for the Synthesis of .n.-Butyrolactones SP - 2418-39 KW - Butyrolactones, synthesis Cinnamaldehyde, N-heterocyclic carbene coupling AB - A review. The N-heterocyclic carbene-catalyzed conjugate umpolung of differently substituted .a.,.b.-unsatd. aldehydes, e. g. cinnamaldehydes, .a.-methylcinnamaldehydes, and crotonaldehydes, is described. Coupling of these compds. with a variety of electrophilic aldehydes and ketones results in the selective formation of highly substituted .b.- and .n.-butyrolactones. JO - Synthesis ER - TY - JOUR AU - Cacchi, S. AU - Fabrizi, G. AU - Goggiamani, A. PY - 2006 TI - The Palladium-Catalyzed Assembly and Functionalization of Benzo[b]Furans SP - 1423-55 KW - Benzo[b]furans, Pd AB - A review. In the past decades, the great potential of Pd catalysis was widely used in the de novo construction of the functionalized benzo[b]furan ring and in the selective functionalization of the preformed benzo[b]furan system providing a broad range of new and versatile procedures. The de novo construction of the benzo[b]furan system generally involves the assembly of the furan nucleus on a benzenoid scaffold via intramol. or intermol. cyclization of compds. contg. O nucleophiles and carbon-carbon triple bonds or carbon-carbon double bonds. Other less frequently used de novo syntheses of the benzo[b]furan system are based on the intramol. Buchwald/Hartwig carbon-oxygen bond forming process and the construction of the benzenoid ring on a furan scaffold. The functionalization of the preformed benzo[b]furan system is usually based on the functionalization via benzofuryl halides or triflates and the functionalization via organometallic derivs. such as benzofurylstannanes, JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Cadierno, V. AU - Crochet, P. AU - Garcia-Garrido, S.E. AU - Gimeno, J. PY - 2006 TI - Bis(allyl)-Ruthenium(IV) Complexes: Promising Precursors for Catalytic Organic Synthesis SP - 165-83 KW - Ruthenium, bis(allyl) complexes AB - A review. The present review reports on the prepn. and chem. of the bis(allyl)-Ru(IV) complexes [{Ru(.h.3:.h.3-C10H16)(.m.-Cl)Cl}2] (C10H16 = 2,7-dimethylocta-2,6-diene-1,8-diyl) and [Ru(h.h3:.h.2:.h.3-C12H18)Cl2] (C12H18 = dodeca-2,6,10-triene-1,12- diyl). Stoichiometric reactions allowing the prepn. of a variety of organoruthenium(IV) and (II) derivs., as well as the involvement of these species in catalytic org. transformations are presented. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Carpenter, B.K. PY - 2006 TI - Electronically Nonadiabatic Thermal Reactions of Organic Molecules SP - 736-747 KW - Chemiluminescent reactions Nonadiabatic thermal reactions AB - This crit. review seeks to bring together org. reactions in which thermal generation of electronic excited states plays an important role. The best known such reactions are those producing chemiluminescent products. However, it appears that there may exist at least as many nonadiabatic reactions in which the excited mols. react before they luminesce. An effort is made to understand the efficiency of excited state prodn. The crucial roles played by reactive intermediates are highlighted. JO - Chemical Society Reviews VL - 35 ER - TY - BOOK AU - Cato, M.A. AU - Ed PY - 2006 BT - Leading Edge Organometallic Chemistry Research CY - Hauppauge, NY PB - Nova Science SP - 225 KW - Organometallics, book ER - TY - JOUR AU - Chen, D. AU - Kotti, S. AU - Li, G. PY - 2005 TI - New Developments on Catalytic Negishi Cross-Coupling Reactions SP - 193-9 KW - Negishi cross-coupling AB - A review. The title work of (G. Fu, et al., 2003-2004) is reviewed with commentary. JO - Chemtracts VL - 18 ER - TY - JOUR AU - Cho, B.T. PY - 2006 TI - Recent Advances in the Synthetic Applications of the Oxazaborolidine- Mediated Asymmetric Reduction SP - 7621-43 KW - Oxazaborolidines Ketones, borane reduction AB - A review. Chiral oxazaborolidine-mediated borane redns. of prochiral ketones and ketimines have been widely utilized for the asym. synthesis of chiral natural products, bioactive compds., etc.; the effective asym. redn. of ketimine derivs. using this methodol. remains a challenging target. JO - Tetrahedron VL - 62 ER - TY - JOUR AU - Chuah, G.K. AU - Jaenicke, S. AU - Zhu, Y.Z. AU - Liu, S.H. PY - 2006 TI - Meerwein-Ponndorf-Verley Reduction over Heterogeneous Catalysts SP - 1639-54 KW - Meerwein-Ponndorf-Verley reduction AB - A review. The Meerwein-Ponndorf-Verley (MPV) transfer hydrogenation of aldehydes and ketones to the corresponding alcs. is distinguished by its exceptional chemoselectivity. This reaction is particularly suited for the redn. of unsatd. aldehydes and ketones, compared to catalytic redns. with H2 using noble metal catalysts. The MPV reaction has traditionally been carried out using homogeneous catalysts like Al or Ti alkoxides. However, over the past two decades, an increasing no. of reports on heterogeneous catalysts for the MPV reaction were published. This interest is stimulated by the advantages of heterogeneous over homogeneous catalysts, particularly for larger-scale applications. The article provides a crit. review of the recent literature on heterogeneous catalysts for the MPV reaction. The materials include hydrotalcites, metal oxides such as Mg oxide, zirconia, SiO2 and alumina, alkoxides of Al, La, Zr and Hf grafted to high surface area mesoporous materials, and zeolites. In particular, zeolite beta is a highly stereoselective catalyst in the MPV redn. of 4-tert-butylcyclohexanone, giving predominantly cis-4-tert-butylcyclohexanol rather than the thermodynamically stable trans-alc. The activity was improved with the incorporation of other metals such as Ti, Sn and Zr. These materials show good tolerance to moisture, lack of leaching and ease of regeneration, thus making them useful catalysts in MPV redn. The activity of a catalyst depends on its ligand exchange capability with the reductant with a high ligand exchange rate enabling the use of catalytic amts. JO - Current Organic Chemistry VL - 10 ER - TY - CHAP AU - Cironi, P. AU - Albericio, F. AU - Alvarez, M. PY - 2004 BT - Progress in Heterocyclic Chemistry, Volume 16 ED - Gribble, G.W. AU - Joule, J.A. AU - Eds CT - Lamellarins: Isolation, Activity and Synthesis. CY - Oxford, U.K. PB - Elsevier SP - 475 KW - Marine alkaloids, book ER - TY - JOUR AU - Clarke, P.A. AU - Santos, S. PY - 2006 TI - Strategies for the Formation of Tetrahydropyran Rings in the Synthesis of Natural Products SP - 2045-53 KW - Tetrahydropyran rings AB - A review. This microreview surveys the literature over the last five years with regard to construction of functionalized tetrahydropyran (THP) rings in the context of the synthesis of natural products. The overview given is intended to provide a working knowledge of the area for those who are unfamiliar, and to refresh and remind those who do work in the area of the exciting developments in the field. While the construction of the THP rings in a no. of natural products has been reviewed, we have attempted to highlight the different strategies by focusing on two natural products, namely phorboxazoles and centrolobine as case studies. Over the last five years, these natural products have become a test bed for new methods for the construction of THP rings. JO - European Journal of Organic Chemistry ER - TY - JOUR AU - Collin, J.-P. AU - Heitz, V. AU - Sauvage, J.-P. PY - 2005 TI - Transition-Metal-Complexed Catenanes and Rotaxanes in Motion: Towards Molecular Machines SP - 29-62 KW - Molecular machines Rotaxanes AB - A review. In the course of the last decade, many dynamic mol. systems, for which the movements are controlled from the outside, have been elaborated. These compds. are generally referred to as "mol. machines". Transition-metal-contg. catenanes and rotaxanes are ideally suited to build such systems. In the present review article, we will discuss a few examples of mol. machines elaborated and studied in Strasbourg. In the first section we will discuss an electrochem. driven system, consisting of copper-complexed catenanes and rotaxanes of various types, including a fast-moving pirouetting rotaxane. The second part will be devoted to chem. driven dynamic mol. systems. A porphyrin-stoppered rotaxane, able to undergo a pirouetting motion by metalation or demetallation of the central coordination site, and a linear rotaxane dimer whose behavior is reminiscent of muscles, will be discussed. In both compds., the mobile component(s) will be set in motion by modifying the central coordination of the mol. assembly. In the rest of this review article, we will mostly focus on light-driven machines, consisting of ruthenium(II)-complexed rotaxanes or catenanes. For these latter systems, the synthetic approach is based on the template effect of an octahedral ruthenium(II) center. Two 1,10-phenanthroline ligands are incorporated in an axis or in a ring, affording the precursor to the rotaxane or the catenane, resp. Ru(diimine)2+3 complexes display the universally used 3MLCT (metal-to-ligand charge transfer) excited state and, another interesting excited state, the 3LF (ligand field) state, which is strongly dissociative. By taking advantage of this latter state, it has been possible to propose a new family of mol. machines, which are set in motion by populating the dissociative 3LF state, thus leading to ligand exchange in the coordination sphere of the ruthenium(II) center. JO - Topics in Current Chemistry VL - 262 ER - TY - JOUR AU - Connon, S.J. PY - 2006 TI - Chiral Phosphoric Acids: Powerful Organocatalysts for Asymmetric Addition SP - 3909-12 KW - Phosphoric acids, chiral, imine addition Imines, asymmetric addition AB - A review. The enormous potential of chiral phosphoric acids as promoters of novel, highly enantioselective addn. reactions to imines under mild conditions has recently been recognized. The use of such catalysts has brought about the development of a no. of new asym. reactions for the synthesis of amine-based chiral building blocks. JO - Angewandte Chemie, International Edition VL - 45 ER - TY - JOUR AU - Connon, S.J. PY - 2006 TI - Organocatalysis Mediated by (Thio)Urea Derivatives SP - 5419-27 KW - Thiourea organocatalysis AB - A review. Over the last decade the potential for N,N-dialkyl(thio)urea derivs. to serve as active metal-free organocatalysts for a wide range of synthetically useful reactions susceptible to the influence of general acid catalysis has begun to be realized. This article charts the development of these catalysts (with emphasis on the design principles involved), from early "proof-of-concept" materials to contemporary active chiral (bifunctional) promoters of highly selective asym. transformations. JO - Chemistry--A European Journal VL - 12 ER - TY - JOUR AU - Conrad, J.C. AU - Fogg, D.E. PY - 2006 TI - Ruthenium-Catalyzed Ring-Closing Metathesis: Recent Advances, Limitations and Opportunities SP - 185-202 KW - Ruthenium, ring-closing metathesis AB - A review. Recent advances in Ru (mostly carbene complex)-catalyzed ring closing metathesis are discussed, in context of both substrate and catalyst parameters. As well as thermodn. (substrate) constraints on ring-closing, root causes and effects of nonideal catalytic performance were examd. Key substrate parameters are outlined, with a particular focus on the balance between oligomerization and ring-closing in RCM macrocyclization reactions. Advances in catalyst design were examd. from a mechanistic viewpoint, including initiation requirements, catalyst deactivation, and opportunities resulting from incorporation of pseudohalide ligands. An overview of methods for reducing Ru residues in org. products to ppm levels is presented. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Conreaux, D. AU - Bouyssi, D. AU - Monteiro, N. AU - Balme, G. PY - 2006 TI - Palladium-Catalyzed Bicyclization Processes in the One Step Construction of Heteropolycyclic Ring Systems SP - 1325-40 KW - Heteropolycyclic systems AB - A review which concerns the prepn. of heteropolycyclic systems in a single operation using Pd complexes and is restricted to methods where the Pd intervenes in at least two sequentially different transformations. JO - Current Organic Chemistry VL - 10 ER - TY - CHAP AU - Conserva, L.M. AU - Filho, J.M.B. PY - 2006 BT - Alkaloids: Chemistry and Biology, Volume 62. ED - Cordell, G.A. AU - Ed CT - Alkaloids of the Hernandiaceae: Occurrence and a Compilation of Their Biological Activities CY - San Diego, CA PB - Elsevier SP - 266 KW - Alkaloids, book ER - TY - JOUR AU - Corbet, J.-P. AU - Mignani, G. PY - 2006 TI - Selected Patented Cross-Coupling Reaction Technologies SP - 2651-710 KW - Cross-coupling reactions AB - A review dealing with cross-coupling reactions : carbon-carbon coupling reactions (Miyaura-Suzuki reaction, Corriu-Kumada-Tamao reaction, Negishi reaction, etc.) and carbon-nitrogen coupling reactions. JO - Chemical Reviews VL - 106(7) ER - TY - JOUR AU - Corbett, P.T. AU - Leclaire, J. AU - Vial, L. AU - West, K.R. AU - Wietor, J.-L. AU - Sanders, J.K.M. AU - Otto, S. PY - 2006 TI - Dynamic Combinatorial Chemistry SP - 3652-711 KW - Combinatorial chemistry, dynamic AB - A review comprehensively discusses all the major aspects of the dynamic combinatorial chem. which is the combinatorial chem. under thermodn. control. The brief history of its development is followed by the discussion of the various reversible reactions, including the exchange reactions (acyl, imine, acetal or disulfide exchange), Diels-Alder reactions, metathesis, or metal-ligand coordination, with the emphasis on the conditions and functional group tolerance. The exptl. issues of the synthesis of dynamic combinatorial libraries are also discussed. This is followed by the section on the application of this approach for the synthesis of various receptors, ligands for biomols., and dynamic combinatorial studies on folding of peptides, nucleotides and synthetic polymers. The review is concluded by the theor. studies of the dynamic combinatorial chem. and discussion of the related approaches. JO - Chemical Reviews VL - 106(9) ER - TY - JOUR AU - Cossy, J. AU - Belotti, D. PY - 2006 TI - Generation of Ketyl Radical Anions by Photoinduced Electron Transfer (PET) between Ketones and Amines. Synthetic Applications SP - 6459-70 KW - Ketones, photoreduction Ketyl radicals AB - A review. Photoredn. of ketones in the presence of amines led to ketyl radicals through photoinduced electron transfer (PET). Tertiary amines, such as triethylamine have frequently been used in these reactions. Different reactions can occur from ketyl radicals such as photoredn., coupling reactions, addns. on activated double bonds, cyclizations, bond cleavage of strained rings, tandem reactions such as cyclization-ring opening or ring opening-cyclization. JO - Tetrahedron VL - 62 ER - TY - JOUR AU - Crabtree, R.H. PY - 2006 TI - Some Chelating C-Donor Ligands in Hydrogen Transfer and Related Catalysis SP - 3146-50 KW - Carbenes, N-heterocyclic AB - A review in symposium. Recent work is discussed that throws light on synthetic, steric, and electronic aspects of NHC complexes as well as on outer sphere effects in their reactivity. The chem. of the NHC ligand is much more complex than the more traditional phosphines and provides much greater possibilities for altering steric and electronic properties for tuning reactivity. In synthetic work the Lin Ag2O method is inapplicable to the synthesis of abnormal NHCs bound via C-4(5) where the C2 position is blocked with CH3, because Ag(I) oxidizes the CH3 group to formate with formation of the normal C-2 bound Ag-NHC. Linker effects on the behavior of chelating NHCs depend on the linker locking the azole rings into a conformation that depends on linker length. This gives rise to different complexes being formed when different linker lengths are employed. The failure of M-NHC bonds to reversibly dissoc. can prevent potentially chelating bis and tris NHC precursors from forming the desired products but instead being trapped in a kinetic nonchelate form. Imidazolium carboxylates prove to be synthetically useful in that they can act as excellent NHC transfer agents to a variety of transition metals. The Tolman electronic parameter of NHCs can be detd. by a variety of exptl. and computational methods. Anion dependent chem. can give rise to a switching of the product of imidazolium salt metalation from normal (C-2) to abnormal (C-4(5)) forms. JO - Journal of Organometallic Chemistry VL - 691 ER - TY - JOUR AU - Creary, X. PY - 2006 TI - Super Radical Stabilizers SP - 761-71 KW - Radical stabilizers AB - A review. A comprehensive series of substituted 1,1-dimethyl-2- methylenecyclopropanes have been thermally rearranged. These rearrangements proceed via singlet biradical intermediates that can be stabilized by substituents. Rates are greatly enhanced by certain groups that are termed super radical stabilizers. Substituents included 4-pyridyl N-oxide, 2-(1,6-methano[10]annulenyl), and a no. of anion-substituted Ph groups. Simple valence bond theory, as well as more sophisticated computational studies, gives insights into modes of radical stabilization. JO - Accounts of Chemical Research VL - 39 ER - TY - JOUR AU - Cuerva, J.M. AU - Justicia, J. AU - Oller-Lopez, J.L. AU - Oltra, J.E. PY - 2006 TI - Cp2TiCl in Natural Product Synthesis SP - 63-91 KW - Epoxide opening, Cp2TiCl AB - A review. The synthesis of complex natural products constitutes one of the most exigent tests to prove the usefulness of a new reagent or catalyst. During the past 10 years, methods based on the Cp2TiCl-promoted and/or -catalyzed radical epoxide opening were used by several authors as the key step for the synthesis of >50 natural products and advanced synthons. At 1st, owing to its selectivity and the extremely mild exptl. conditions employed, stoichiometric Cp2TiCl was chosen for deoxygenation and reductive epoxide opening on densely functionalized substrates, but during the last 5 years catalytic Cp2TiCl was increasingly employed to achieve radical cyclizations of different epoxyalkenes and epoxyalkynes, affording straightforward strategies for the synthesis of complex natural products. In these fields Cp2TiCl-based methods have already largely proved their synthetic usefulness but other Cp2TiCl-mediated reactions have as yet been scarcely applied. This review focuses on the increasing scope of applications that employ the Cp2TiCl-mediated procedures in the synthesis of natural products. The authors also present the basic concepts of these methods to facilitate and encourage further synthetic applications. JO - Topics in Current Chemistry VL - 264 ER - TY - BOOK AU - Curran, D.P. AU - Mikami, K. AU - Soloshonok, V.A. AU - Eds PY - 2006 BT - Special Issue: Current Frontiers of Fluoroorganic Chemistry and Recent Advances in Fluorous Chemistry. [In: J. Fluorine Chem.; 2006, 127(4-5)] CY - Amsterdam, Netherlands PB - Elsevier KW - Fluoroorganic chemistry, book ER - TY - JOUR AU - Daasbjerg, K. AU - Svith, H. AU - Grimme, S. AU - Gerenkamp, M. AU - Mueck-Lichtenfeld, C. AU - Gansaeuer, A. AU - Barchuk, A. PY - 2006 TI - The Mechanism of Epoxide Opening through Electron Transfer: Experiment and Theory in Concert SP - 39-69 KW - Epoxides, opening AB - This review gives a description of the mechanism of reductive epoxide opening through single-electron transfer. A no. of electron-transfer reagents are compared and the most promising titanocene complexes are studied in detail. The mechanism of epoxide opening was established by cyclic voltammetry, kinetic measurements, DFT calcns., and synthetic studies. The results are used to devise more selective reagents. JO - Topics in Current Chemistry VL - 263 ER - TY - JOUR AU - Dahlenburg, L. PY - 2005 TI - P-Modular Bis(phosphines) Based on the 1,2-Trans-Disubstituted Cyclopentane Framework in Synthesis, Coordination Chemistry, and Catalysis SP - 2962-92 KW - Phosphines, bidentate AB - A review. The review describes a class of versatile bidentate phosphines having a homochiral 1,2-disubstituted cyclopentane backbone, the use of such ligands in coordination chem., and their application in transition metal-catalyzed synthesis, including C-H activation, C-C coupling, ?C:C? hydrogenation, and hydroformylation. In particular, the synthetic potential of the multi-purpose P-H and P-Cl reagents (R,R)- and (S,S)-C5H8(PX2)2 (X = H, Cl) is highlighted, since these open up the possibility to incorporate virtually any other P-O-, P-N- or P-C-bonded residue (module) into the homochiral bis(phosphine) framework. The resulting chelating ligands allow access to transition metal catalysts with stereodiscriminating properties detd. by parameters such as (i) the presence of P-substituents that are equal or pairwise different in steric demand, (ii) the spatial orientation of such substituents with respect to the coordination plane of the catalyst complex, and (iii) the combination of C- and P-chirogenic stereo elements in matched (or mismatched) fashion. A comparative discussion of the crystal structures that are currently available for the free ligands and their transition metal complexes is also presented. JO - Coordination Chemistry Reviews VL - 249 ER - TY - BOOK AU - Danheiser, R.I. AU - Ed PY - 2006 BT - Compounds with Four and Three Carbon-Heteroatom Bonds. Three Carbon-Heteroatom Bonds: Ketenes and Derivatives. [In: Sci. Synth.; 2006, 23] CY - Stuttgart, Germany PB - Georg Thieme Verlag SP - 1054 KW - Carbon heteroatom bonds, book Ketene derivatives, book ER - TY - JOUR AU - Das, S. AU - Incarvito, C.D. AU - Crabtree, R.H. AU - Brudvig, G.W. PY - 2006 TI - Molecular Recognition in the Selective Oxygenation of Saturated C-H Bonds by a Dimanganese Catalyst SP - 1941-3 KW - C-H bonds, selective oxygenation Hydrogen bonds in molecular recognition AB - Although enzymes often incorporate mol. recognition elements to orient substrates selectively, such strategies are rarely achieved by synthetic catalysts. The authors combined mol. recognition through hydrogen bonding JO - Science VL - 312(5782) ER - TY - JOUR AU - de Carvalho da Silva, F. PY - 2006 TI - Synthetic Applications of Lithium Hydroxide SP - 1451-2 KW - Lithium hydroxide, in synthesis AB - A brief review on LiOH as a mild and efficient reagent in org. synthesis. JO - Synlett ER - TY - JOUR AU - de Vries, J.G. AU - Lefort, L. PY - 2006 TI - The Combinatorial Approach to Asymmetric Hydrogenation: Phosphoramidite Libraries, Ruthenacycles, and Artificial Enzymes SP - 4722-34 KW - Combinatorial chemistry, asymmetric hydrogenation Phosphoramidite libraries Ruthenacycles, libraries Enzymes, artificial, libraries AB - A review discusses a high-throughput experimentation (HTE) approach, which makes possible the dramatically accelerated screening for new catalysts and ligands for a more general implementation of asym. catalysis in the prodn. of fine chems. The implementation of this technol. requires the rapid prepn. of libraries of ligands/catalysts and consequently dictates the use of simple ligands that can be readily synthesized in a robot. In this concept article, it is described how the development of new ligands based on monodentate phosphoramidites enabled the development of an integral HTE protocol for asym. hydrogenation. This "instant ligand library" protocol makes it possible to synthesize 96 ligands in one day and screen them the next day. Further diversity is possible by using mixts. of monodentate ligands. This concept has already led to an industrial application. Other concepts, still under development, are based on chiral ruthenacycles as new transfer hydrogenation catalysts and the use of enzymes as ligands for transition-metal complexes. JO - Chemistry--A European Journal VL - 12 ER - TY - JOUR AU - Deagostino, A. AU - Prandi, C. AU - Zavattaro, C. AU - Venturello, P. PY - 2006 TI - Functionalized 1-Alkoxy-1,3-Dienes: Their Preparation and Applications in Synthetic Organic Chemistry SP - 2463-83 KW - Alkoxydienes AB - A review. The reaction of various .a.,.b.-unsatd. acetals with two equiv. of the Schlosser reagent LIC-KOR [equimolar mixt. of BuLi (LIC), and tBuOK (KOR)] gives 1-metalated (1E)-1-alkoxy-1,3-dienes. These products can be transformed into trienic derivs. that are apt to participate in intramol. Diels-Alder (IMDA) cycloaddn. reactions, and can also be transformed into bifunctional (.n.-halo-.a.-carbonyl) reagents. Moreover, the metalated dienes can be readily functionalized with suitable electrophiles to afford products that have been found to be useful reagents for the Stille and Suzuki cross-coupling reactions or arylated according to the conditions of the Heck process. Other significant syntheses of dienic and polyenic structures are reported along with some of their applications in org. synthesis. JO - European Journal of Organic Chemistry ER - TY - JOUR AU - Delacroix, O. AU - Gaumont, A.C. PY - 2005 TI - Hydrophosphination of Unactivated Alkenes, Dienes and Alkynes: A Versatile and Valuable Approach for the Synthesis of Phosphines SP - 1851-82 KW - Alkenes, hydrophosphination Phosphines, synthesis AB - A review. A greener way to phosphines for use in catalysis is the addn. of a P-H bond to a multiple bond since no atom loss is obsd. (atom economy concept). These reactions are mainly carried out in the presence of radical initiators or under basic conditions. Acidic and neutral media are also proposed. A few recent examples reported the use of a metal activation. This review is designed to remember some of the early aspects of hydrophosphination reactions using phosphines, protected or not, and unactivated or slightly activated alkenes, dienes and alkynes and to focus on the more promising results obtained in this field for the last 15 years. The reactions involving pentavalent P derivs. (phosphine-oxide, phosphine sulfides, phosphonate and phosphate derivs. etc.) are not included. JO - Current Organic Chemistry VL - 9 ER - TY - JOUR AU - Delaude, L. AU - Demonceau, A. AU - Noels, A.F. PY - 2006 TI - Synthesis and Application of New N-Heterocyclic Carbene Ruthenium Complexes in Catalysis: A Case Study SP - 203-15 KW - Carbenes, N-heterocyclic, Ru-complex AB - A review. New imidazolium and imidazolinium salts were synthesized and their ability to act as stable N-heterocyclic carbene (NHC) ligand precursors was studied in various Ru-catalyzed processes. Thus, 1,3-diarylimidazol(in)ium chlorides bearing the Ph, 1-naphthyl, 4-biphenyl, 3,5-dimethylphenyl, 2-tolyl, 2,6-dimethylphenyl, 2,4,6-trimethylphenyl (mesityl), and 2,6-diisopropylphenyl substituents were prepd. They were combined with the [RuCl2(p-cymene)]2 dimer and KOtBu or NaH to generate the corresponding Ru-arene complexes [RuCl2(p-cymene)(NHC)] in situ. The catalytic activity of all these species was studied in the photoinduced ring-opening metathesis polymn. (ROMP) of norbornene and cyclooctene. Results from this study showed that the C4-C5 double bond in the imidazole ring of the NHC ligands was not crucial to achieve high catalytic efficiencies. The presence or the absence of alkyl groups on the ortho positions of the Ph rings had a more pronounced influence. Blocking all the ortho positions was a requisite for obtaining efficient catalysts. Failure to do so probably resulted in the ortho-metalation of the carbene ligand, thereby altering the coordination sphere of the Ru active centers. Catalytic screenings were also carried out with the various imidazol(in)ium salts to evaluate their ability at promoting the cyclopropanation of styrene and cyclooctene with Et diazoacetate. Under the exptl. conditions adopted, the exact nature of the N,N'-diaryl groups had very little influence on the outcome of these reactions. The imidazolium salts were further probed as catalyst modifiers for the Atom Transfer Radical Addn. (ATRA) of CCl4 to styrene. Some species displayed a dual activity and promoted both olefin metathesis and ATRA. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Denisov, E.T. AU - Tumanov, V.E. PY - 2005 TI - Estimation of the Bond Dissociation Energies from the Kinetic Characteristics of Liquid-Phase Radical Reactions SP - 825-58 KW - Radical reactions, liquid, kinetics AB - A review. Three methods used in the kinetics of liq.-phase radical reactions for estg. the dissocn. energies of individual bonds in polyat. mols. are described. The first approach is based on the study of the equil. in radical abstraction reactions involving stable radicals and measurements of the equil. consts. The second method is based on the study of the kinetics of homolytic decompn. of mols. Measuring the activation energy of these reactions makes it possible to est. the dissocn. energies of the weakest bonds, e.g., the O-O bonds in various peroxides. The essence of the third approach developed in the framework of the model of intersecting parabolas is calcns. of the bond dissocn. energy from the activation energy of a radical reaction involving the mols. under consideration. This method allowed the dissocn. energies of the C-H, N-H, O-H and S-H bonds in a large no. of org. compds. to be estd. The scope and the specific features of application of each method are discussed and the bond dissocn. energies detd. by these methods are given. JO - Russian Chemical Reviews VL - 74 ER - TY - JOUR AU - Denmark, S.E. AU - Baird, J.D. PY - 2006 TI - Palladium-Catalyzed Cross-Coupling Reactions of Silanolates: A Paradigm Shift in Silicon-Based Cross-Coupling Reactions SP - 4954-63 KW - Silanolates, cross-coupling, Pd AB - A review. This paper chronicles the conceptual development, proof of principle expts., and recent advances in the palladium-catalyzed cross-coupling reactions of the conjugate bases of organosilanols. The discovery that led to the design and refinement of this process represents a classical illustration of how mechanistic studies can provide a fertile ground for the invention of new reactions. On the basis of a working hypothesis (which ultimately proved to be incorrect) and the desire to effect silicon-based cross-coupling without the agency of fluoride activation, a mild and practical palladium-catalyzed cross-coupling of alkenyl-, aryl-, and heteroaryl silanolates has been developed. The mechanistic underpinnings, methodol. extensions, and the successful applications of this technol. to the synthesis of complex mols. are described. JO - Chemistry--A European Journal VL - 12 ER - TY - CHAP AU - Dennis, L.W. PY - 2005 BT - Progress in Heterocyclic Chemistry ED - Gribble, G.W. AU - Joule, J.A. AU - Eds CT - Furans as Versatile Synthons for Target-Orientated and Diversity-Orientated Synthesis. CY - Oxford, U.K. PB - Elsevier SP - 449 KW - Furans, book VL - 17 ER - TY - JOUR AU - Desimoni, G. AU - Faita, G. AU - Jorgensen, K.A. PY - 2006 TI - C2-Symmetric Chiral Bis(oxazoline) Ligands in Asymmetric Catalysis SP - 3561-651 KW - Chiral bis(oxazoline) ligands AB - A review discusses the various aspects of chem. of C2-sym. chiral bis(oxazoline) (Box) ligands. It includes the methods for synthesis of these ligands, the prepn. and structure of their metal complexes, and application of the Box ligands in asym. catalysis. The reviewed reactions catalyzed by BOX ligands include inter- and intramol. cyclopropanation, aziridination, aldol and similar reactions, Michael and Mukaiyama-Michael reactions, homolytic reactions, Diels-Alder, hetero-Diels-Alder and 1,3-dipolar cycloaddn., ene, hetero-ene, and other pericyclic reactions. The effects of the ligand substituents on the stereochem. outcome of the reactions are discussed in detail. The formation of complexes of bis(oxazoline)s with various inorg. salts and their application as asym. catalysts are also reviewed. JO - Chemical Reviews VL - 106(9) ER - TY - JOUR AU - Ding, K. AU - Wang, Z. AU - Wang, X. AU - Liang, Y. AU - Wang, X. PY - 2006 TI - Self-Supported Chiral Catalysts for Heterogeneous Enantioselective Reactions SP - 5188-97 KW - Chiral catalysts, self-supported Heterogeneous binaphthyl catalysts AB - A review discusses the concept of self-supported chiral catalysis (the generation of heterogeneous catalysts by metal complexation with unsupported polydentate nonracemic ligands, particularly binaphthyl-contg. ligands) and the use of such catalysts in enantioselective carbonyl-ene reactions, oxidn., epoxidn., and hydrogenation reactions. JO - Chemistry--A European Journal VL - 12 ER - TY - JOUR AU - d'Ischia, M. AU - Napolitano, A. AU - Pezzella, A. AU - Land, E.J. AU - Ramsden, C.A. AU - Riley, P.A. PY - 2005 TI - 5,6-Dihydroxyindoles and Indole-5,6-diones SP - 1-63 KW - Dihydroxyindoles Indole-5,6-diones AB - A review covering the phys. properties, prepn. and reactions of 5,6-dihydroxyindoles, 2,3-dihydro-5,6-dihydroxyindoles, 2,3-dihydro-1H-indole-5,6-diones and indole-5,6-diones. JO - Advances in Heterocyclic Chemistry ER - TY - JOUR AU - Dolzhenko, A.V. AU - Dolzhenko, A.V. AU - Chui, W.-K. PY - 2006 TI - 1,2,4-Triazolo[1,5-a][1,3,5]Triazines (5-Azapurines): Synthesis and Biological Activity SP - 1723-59 KW - Azapurines Triazolotriazines AB - A review (88 refs.) giving an account of the various synthetic routes to the 5-aza-analog of purine - 1,2,4-triazolo[1,5-a][1,3,5]triazine nucleus and polyfused systems bearing this heterocyclic core. Syntheses by annulation of the 1,3,5-triazine ring onto 1,2,4-triazole scaffold or of the 1,2,4-triazole ring onto 1,3,5-triazine scaffold were considered, as well as the concurrent formation of both rings and the ring transformations. Data concerning biol. activity of the compds. with 1,2,4-triazolo[1,5-a][1,3,5]triazine skeleton were also discussed. JO - Heterocycles VL - 68 ER - TY - JOUR AU - Dondoni, A. AU - Massi, A. PY - 2006 TI - Design and Synthesis of New Classes of Heterocyclic C-Glycoconjugates and Carbon-Linked Sugar and Heterocyclic Amino Acids by Asymmetric Multicomponent Reactions (AMCRs) SP - 451-63 KW - Glycoconjugates, multicomponent reactions AB - A review. While chem. efficiency relies on several factors, the multicomponent reaction (MCR) approach was considered as a powerful synthetic tool for prepg. target mols. of biol. relevance in an efficient manner. Four classes of new bioactive mols. were designed and synthesized by asym. MCRs, in some cases with the cooperation of polymer-assisted soln.-phase technique. These include (a) C-glycosyl dihydropyrimidines and dihydropyridines via Biginelli and Hantzsch cyclocondensations, (b) C-glycosyl .b.-amino acids via Mannich- and Reformatsky-type reactions, (c) C-glycosyl .b.-lactams via Staudinger reaction, and (d) heterocyclic .a.-amino acids (glycine and alanine) via the Biginelli and Hantzsch reactions. JO - Accounts of Chemical Research VL - 39 ER - TY - JOUR AU - Donohoe, T.J. AU - Orr, A.J. AU - Bingham, M. PY - 2006 TI - Ring-Closing Metathesis as a Basis for the Construction of Aromatic Compounds SP - 2664-70 KW - Aromatics, via ring-closing metathesis AB - A review. The use of metathesis, esp. in the context of ring-closing metathesis (RCM) to form five- and six-membered rings, is widespread in org. chem. today. However, there are surprisingly few examples of the reaction being used to form arom. compds. The central place of arom. compds. in both medicinal chem. and natural products synthesis, coupled with the efficiency and functional group tolerance of RCM catalysts, means that there is now an interesting opportunity to use RCM for the synthesis of arenes. Although the formation of an arom. compd. was viewed in many early examples as an undesirable degrdn. product, several rationally designed methods towards the prepn. of arom. compds. by RCM have recently been developed. JO - Angewandte Chemie, International Edition VL - 45 ER - TY - JOUR AU - Du, H. AU - He, Y. AU - Sivappa, R. AU - Lovely, C.J. PY - 2006 TI - New Methods of Imidazole Functionalization - From Imidazole to Marine Alkaloids SP - 965-92 KW - Imidazoles AB - A review. The pyrrole-imidazole family of marine alkaloids, the so-called oroidin natural products, exhibits an impressive diversity of structural motifs. The majority of these natural products contain one or more imidazole moieties intricately embedded within a polycyclic framework and thus present significant challenges to extant synthetic methods. Our approach to this problem has centered on the development of methods for the elaboration of simple imidazoles. This review describes the results of these efforts leading to the development of a variety of methods, including cycloaddns., oxidative and transition-metal-catalyzed reactions (e.g., with .p.-allylpalladium). JO - Synlett ER - TY - JOUR AU - Dunina, V.V. AU - Gorunova, O.N. PY - 2005 TI - Phosphapalladacycles: Forms of Existence and Reactions SP - 871-913 KW - Phosphapalladacycles AB - A review of the reactivity of cyclopalladated complexes with P donor atoms are discussed, in particular, the routes of modification of the metal coordination environment in phosphapalladacycles by diverse auxiliary ligands; the transformations of phosphapalladacycles involving the Pd-C bond; the modification of phosphapalladacycles with retention of the Pd-C bond; and dechelation and destruction of phosphapalladacycles. The regiochem. of ligand coordination to PC-palladacycles is considered from the standpoint of the trans-effect of the P-and C-donor atoms of the palladacycle. The bibliog. includes 359 refs. JO - Russian Chemical Reviews VL - 74 ER - TY - JOUR AU - Dyachenko, V.D. AU - Tkachev, R.P. PY - 2006 TI - Functionally-Substituted Alkoxyethylenes in Reactions with Nucleophiles: Part 2. Synthesis of Noncyclic Structures, Benzene Derivatives, 5-, 7-Membered, and Macroheterocycles SP - 149-71 KW - Alkoxyethylenes AB - The review systematizes and generalizes the published data on the synthesis of cyclic (with the exception of six-membered) and linear structures based on functionally-substituted alkoxy olefins. In some cases the direction of the reaction was demonstrated to depend on its conditions. The data are also presented on the established biol. activity of compds. obtained. JO - Russian Journal of Organic Chemistry VL - 42 ER - TY - JOUR AU - Dzhemilev, U.M. AU - Ibragimov, A.G. PY - 2005 TI - Metal Complex Catalysis in the Synthesis of Organomagnesium Compounds SP - 807-23 KW - Organomagnesium compounds AB - A review. The published data on the synthesis of organomagnesium compds. assisted by metal complex catalysts are generalized and described systematically for the 1st time. Hydro-, carbo- and cyclomagnesiation reactions of unsatd. compds. with R1MgR2 (R1 = Alk, Ar; R2 = H, Hal; R1 = R2 = Alk) catalyzed by Ti, Zr and other transition metal salts and complexes are considered. Selected examples of applications of organomagnesium reagents to org. synthesis are given. The bibliog. includes 206 refs. JO - Russian Chemical Reviews VL - 74 ER - TY - JOUR AU - Egorov, I.N. AU - Zyryanov, G.V. AU - Rusinov, V.L. AU - Chupakhin, O.N. PY - 2005 TI - Asymmetric Induction in the Nucleophilic Addition in the Series of Aromatic Azines SP - 1073-87 KW - Aromatic azines AB - A review. Stereoselective reactions of nucleophilic addn. to the C = N bond in arom. azines resulting in chiral products are reviewed. Various methods of inducing the optical activity are discussed. The bibliog. includes 60 refs. JO - Russian Chemical Reviews VL - 74 ER - TY - BOOK AU - El Ashry, E.S.H. AU - El Nemr, A. PY - 2005 BT - Synthesis of Naturally Occurring Nitrogen Heterocycles from Carbohydrates CY - Oxon, U.K. PB - Blackwell SP - 464 KW - Heterocycles, N-, from carbohydrates, book ER - TY - CHAP AU - Emidio Vasconcelos Leitao, d.-C. AU - et al. PY - 2006 BT - Alkaloids: Chemistry and Biology, Vol. 62. ED - Cordell, G.A. AU - Ed CT - Protoberberine Alkaloids CY - San Diego, CA PB - Elsevier SP - 266 KW - Alkaloids, book ER - TY - JOUR AU - Epsztajn, J. AU - Jozwiak, A. AU - Szczesniak, A.K. PY - 2006 TI - Secondary Amides as Ortho-Directed Metalation Groups for Arenes; A Useful Construction Way of the Polysubstituted Aromatic and Heteroaromatic Systems SP - 1817-48 KW - Aromatics, ortho-substitution, Li AB - A review. The lithiation electrophilic substitution sequence of arom. compds. has become very a common methodol. for ortho-introduction of a long list of substituents in general. In particular, it was centered around the ortho-substitution of arom. carboxylic acids via their masked forms. Till now, long list of reviews concerning tertiary amides or oxazolines as directing groups was referred. However, secondary amides, even historically 1st masked function of arom. carboxylic acids, are discussed in much smaller extent. In here, the scope of this methodol. and the application of the secondary amide function in org. synthesis is presented. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Exner, O. AU - Bohm, S. PY - 2006 TI - Theory of Substituent Effects: Recent Advances SP - 763-78 KW - Substituent effects AB - A review. The review reports recent progress in the studies of substituent effects in isolated mols., i. e. based either on the exptl. gas-phase acidities (basicities), or on quantum chem. calcns. Attention was focused on cases when the results differed from or exceeded the traditional views: redefinition of the inductive effect, quant. estn. of resonance, validity of the Hammett equation, interpretation of the ortho effect, additivity of the enthalpies of formation, acidity of carboxylic acids. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Farina, V. AU - Reeves, J.T. AU - Senanayake, C.H. AU - Song, J.J. PY - 2006 TI - Asymmetric Synthesis of Active Pharmaceutical Ingredients SP - 2734-2793 KW - Asymmetric synthesis, pharmaceuticals AB - A review. Synthetic methods including chiral synthetic targets, chiral auxiliaries, aldol reaction of enolates, propionate-type aldol reaction, acetate-type aldol reaction, alkylation, conjugate addn., conjugate addn. of nitrogen-based nucleophiles, conjugate addn. of carbon-based nucleophiles, nucleophilic addn., etc. were discussed. JO - Chemical Reviews VL - 106(7) ER - TY - JOUR AU - Fehlner, T.P. PY - 2006 TI - Reactions of Alkynes with Metallaboranes: Novel Reactivities Lead to New Structure Types SP - 1323-31 KW - Metallaboranes, with alkynes AB - A review with 27 refs. on reactivity of lower rhoda- and ruthenaborane cluster half-sandwich complexes with alkynes. The reactions of alkynes with nido-dimetallaboranes contg. monocyclopentadienyl metal fragments are highly dependent on metal identity. Typical metals from groups 6 and 7 do not react under mild conditions, Rh gives exclusively alkyne cyclotrimerization via a cluster-catalyzed reaction, and Ru reacts predominantly via insertion to give new ruthenacarborane clusters. The facile reaction obsd. for Ru permits the characterization of intermediates exhibiting novel structural features, e.g., external cluster-bridging monoborane or alkylidene fragments. Despite the large differences in reactivity, circumstantial evidence suggests the alkyne adds to and opens the metallaborane to an arachno-structure. The metal present dets. the character of the metallaborane, which in turn dets. whether further JO - Pure and Applied Chemistry VL - 78 ER - TY - JOUR AU - Figueras, F. AU - Kantam, M.L. AU - Choudary, B.M. PY - 2006 TI - Solid Base Catalysts in Organic Synthesis SP - 1627-37 KW - Hydrotalcites, in synthesis Fluorides, supported, in synthesis AB - A review. The basic and catalytic properties of hydrotalcites, supported fluorides and mixed oxides are reviewed, with a special emphasis on C-C bond forming reactions. Relatively strong basicity can be induced on hydrotalcites by calcination followed by rehydration. In that case the shift from Lewis to Bronsted basicity has strong influence on the catalytic properties. The basicity is further enhanced by introduction of t-butoxide or fluoride anions in place of hydroxyls, while chloride anions inhibit activity. Excellent yields are reported, by fine-tuning of basic sites of the hydrotalcites, supported fluorides and mixed oxides as exemplified in aldol, Henry, Knoevenagel, Michael, trans-esterification Wadsworth- Emmons and N-oxidn. reactions. In many cases the catalysts can be recycled. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Focante, F. AU - Mercandelli, P. AU - Sironi, A. AU - Resconi, L. PY - 2006 TI - Complexes of Tris(Pentafluorophenyl)Boron with Nitrogen-Containing Compounds: Synthesis, Reactivity and Metallocene Activation SP - 170-88 KW - Metallocene activation Tris(pentafluorophenyl)boron-N complexes AB - A review. The strong Lewis acid tris(pentafluorophenyl)boron, B(C6F5)3, reacts with several N-contg. Lewis bases (nitriles, amines, imines, pyridines, etc.) and also with non-basic substrates (such as pyrroles and indoles) producing in both cases the B-N coordination adduct. With particular substrates (some tertiary amines, the imine tBu(Me)C:NBn, N-methyl-pyrrole and -indole) the 1:1 borane/N-compd. reaction produces zwitterions where a new B-C bond was generated. Some of the borane-N-compd. adducts present Bronsted acidity and can be reacted with di-Me Group 4 complexes with generation of weakly assocd. ion pairs, which are active catalysts for the polymn. of olefins. JO - Coordination Chemistry Reviews VL - 250 ER - TY - JOUR AU - Franck, R.W. AU - Tsuji, M. PY - 2006 TI - .a.-C-Galactosylceramides: Synthesis and Immunology SP - 692-701 KW - Galactosylceramides Glycolipids AB - A review with refs. The immunostimulant activity of .a.- galactosylceramides provided the impetus for the research described here. The activity was first discovered via screening of exts. of a marine sponge. The active materials purified from the exts. were .a.-O-galactosylceramides. The work described herein focuses on syntheses of .a.-C-galactosylceramides. Crucial methodologies for the syntheses were (i) Ramberg-Backlund reaction, (ii) modified Julia olefination, (iii) olefin cross-metathesis, and (iv) Sharpless asym. epoxidn. in four independent routes. The immunostimulant activity in mice of the synthetic .a.-C-galactosylceramide far surpasses that of the O-galactosyl material. A discussion of the reasons for the difference in activity is presented. The C-glycolipid is about 100-fold more effective than the O-analog. JO - Accounts of Chemical Research VL - 39 ER - TY - JOUR AU - Freund, C. AU - Abrantes, M. AU - Kuehn, F.E. PY - 2006 TI - Monomeric Cyclopentadiene Molybdenum Oxides and Their Carbonyl Precursors as Epoxidation Catalysts SP - 3718-29 KW - Epoxidation catalysts Cyclopentadiene molybdenum oxides AB - A review. Monomeric cyclopentadiene molybdenum oxides were among the first synthesized high oxidn. state organometallics. However, their syntheses and applications have long been overshadowed by their rhenium(VII) congeners, in particular by (pentamethylcyclopentadienyl)trio xorhenium(VII) and methyltrioxorhenium(VII). Only during the last decade a renaissance of the cyclopentadienyl molybdenum oxides is starting. Both with respect to synthetic access ways and to applications as oxidn. catalysts in homogeneous and heterogeneous phase the interest in cyclopentadienyl molybdenum oxides and their tricarbonyl precursors is increasing. This results from the usually time-easy and straightforward synthetic procedures leading to these compds. and their easy heterogenizability, both on mesoporous materials and in ionic liqs. The catalytic performance, esp. in olefin epoxidn. with tert- butylhydroperoxide being the oxidant is very good and the derivatization to reach taylor made catalysts seems to be much easier than in the case of the organorhenium oxides. Another advantage in comparison to the latter complexes is the possible presence of two org. functionalities, which can be independently modified, e.g. for heterogenization of the complexes and for the enhancing of their catalytic activity at the same time. JO - Journal of Organometallic Chemistry VL - 691 ER - TY - JOUR AU - Frlan, R. AU - Kikelj, D. PY - 2006 TI - Recent Progress in Diaryl Ether Synthesis SP - 2271-85 KW - Diaryl ethers, synthesis AB - A review. Diaryl ethers form an important class of org. compds., both in life sciences and in the polymer industry. In general, diaryl ethers can be synthesized by means of copper-catalyzed Ullmann diaryl ether coupling, palladium-catalyzed Buchwald-Hartwig reaction, nucleophilic arom. substitution, arylboronic acid-diaryl ether coupling, oxidative coupling, and nucleophilic arom. addn. to metal-arene complexes. This review covers the progress in diaryl ether synthesis since 1999, with literature coverage through Sept. 2005. JO - Synthesis ER - TY - JOUR AU - Fu, G.C. PY - 2006 TI - Applications of Planar-Chiral Heterocycles as Ligands in Asymmetric Catalysis SP - 853-60 KW - Heterocycles, planar, chiral AB - A review. A new family of ligands for asym. transition metal-catalyzed reactions has been designed and synthesized. Thus, planar-chiral heterocycles furnish high enantioselectivity in a variety of processes, including isomerizations of allylic alcs., O-H insertions, and 1,3-dipolar cycloaddns. JO - Accounts of Chemical Research VL - 39 ER - TY - JOUR AU - Gale, P.A. PY - 2006 TI - Structural and Molecular Recognition Studies with Acyclic Anion Receptors SP - 465-75 KW - Anion receptors Isophthalamide anion complex Amidopyrroles Phenylenediamine bis-ureas AB - A review. Acyclic mols. contg. amides, ureas, and pyrrole groups have proven to be effective and selective anion-binding agents. In this Account, the structural chem. of isophthalamide anion complexes, ortho-phenylenediamine based bis-ureas, and amidopyrroles, as well as anion-triggered deprotonation processes in neutral anion receptor systems, are discussed. JO - Accounts of Chemical Research VL - 39 ER - TY - JOUR AU - Gallou, I. AU - Senanayake, C.H. PY - 2006 TI - Cis-1-Amino-2-Indanol in Drug Design and Applications to Asymmetric Processes SP - 2843-74 KW - Amino-2-indanol JO - Chemical Reviews VL - 106(7) ER - TY - JOUR AU - Garcia, C. AU - Martin, V.S. PY - 2006 TI - Asymmetric Addition to Ketones: Enantioselective Formation of Tertiary Alcohols SP - 1849-89 KW - Ketones, asymmetric addition Alcohols, chiral tertiary AB - A review. The stereoselective formation of chiral tertiary alcs. is of great importance for the synthesis of enantiomerically pure natural products and pharmaceuticals. The simplest approach for the prepn. of chiral alcs. is the enantioselective addn. of organometallic reagents to carbonyl compds. Hundreds of catalysts promote nucleophilic addns. of organometallic compds. to aldehydes with high enantioselectivities. However, the use of ketones as group acceptors under similar conditions proved much more challenging. The chem. of catalytic asym. addns. to ketones is progressing, esp. since 1998. This review attempts to cover advances in this field which occurred between 1994-2004. Particular attention is paid to chiral auxiliaries, reagents and catalysts used for the addn. to different kinds of ketones (arom. and aliph. ketones, .a.,.b.-unsatd. ketones, .a.-ketoesters) as well as the enantiomeric excesses of the chiral tertiary alcs. obtained for each case. A discussion about the progress in the catalytic asym. addn. to ketoimines to generate enantiomerically enriched tertiary amines will be presented. Finally, recent applications of the asym. addn. to ketones chem. in the synthesis of natural products and related compds. are reported. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Garnovskii, D.A. AU - Kukushkin, V.Y. PY - 2006 TI - Metal-Mediated Reactions of Oximes SP - 111-24 KW - Oximes, metal-mediated AB - A review. The published data on metal-mediated reactions of oximes are described systematically. The attention is focused on the reactions that serve as convenient methods for the synthesis of various org. compds. or models for the interpretation of the mechanisms of catalytic processes and the reactions resulting in new ligand systems. The bibliog. includes 182 refs. JO - Russian Chemical Reviews VL - 75 ER - TY - JOUR AU - Gibson, S.E. AU - Castaldi, M.P. PY - 2006 TI - C3 Symmetry: Molecular Design Inspired by Nature SP - 4718-20 KW - Catalyst, C3-symmetric AB - A review. Symmetry and mol. recognition: The presence of C3 symmetry in nature has recently inspired the first biomimetic C3-sym. catalyst for asym. syntheses. Threefold symmetry also features in a recent approach to modulating the function of the tumor necrosis factor receptor superfamily. JO - Angewandte Chemie, International Edition VL - 45 ER - TY - JOUR AU - Gnas, Y. AU - Glorius, F. PY - 2006 TI - Chiral Auxiliaries - Principles and Recent Applications SP - 1899-930 KW - Chiral auxiliaries AB - A review. With modern methods for asym. catalysis breaking ground, the use of chiral auxiliaries seems to be old-fashioned and rather inefficient. However, for many transformations, chiral auxiliaries represent the only selective method available. In addn., high levels of selectivity and reliability are often attractive characteristics of chiral auxiliaries and allow for the efficient and rapid synthesis of desired chiral compds. In addn., even in cases with imperfect selectivity, the use of an attached chiral auxiliary allows the enrichment of diastereoselectivity, and hence enantioselectivity after removal of the auxiliary, by many std. sepn. techniques. This article gives an overview on the most important classes of chiral auxiliaries, discussing the mode of action and highlighting some recent applications. It does not deal with the use of chiral catalysts, chiral reagents or achiral auxiliaries. JO - Synthesis ER - TY - JOUR AU - Goossen, L.J. AU - Deng, G. AU - Levy, L.M. PY - 2006 TI - Synthesis of Biaryls via Catalytic Decarboxylative Coupling SP - 662-4 KW - Biaryls, synthesis AB - We present a safe and convenient cross-coupling strategy for the large-scale synthesis of biaryls, com. important structures often found in biol. active mols. In contrast to traditional cross-couplings, which require the prior prepn. of organometallic reagents, we use a copper catalyst to generate the carbon nucleophiles in situ, via decarboxylation of easily accessible arylcarboxylic acid salts. The scope and potential economic impact of the reaction are demonstrated by the synthesis of 26 biaryls, one of which is an intermediate in the large-scale prodn. of the agricultural fungicide Boscalid. JO - Science VL - 313(5787) ER - TY - BOOK AU - Griesbeck, A.G. AU - Ed PY - 2006 BT - Compounds with Two Carbon-Heteroatom Bonds: Quinones and Heteroatom Analogues. [In: Sci. Synth.; 2006, 28] CY - Stuttgart, Germany PB - Georg Thieme Verlag SP - 1006 KW - Quinones, book ER - TY - JOUR AU - Gritsan, N.P. AU - Platz, M.S. PY - 2006 TI - Kinetics, Spectroscopy, and Computational Chemistry of Arylnitrenes SP - 3844-67 KW - Arylnitrenes AB - The present review highlights recent developments in the understanding of the spectroscopy and kinetics of arylnitrenes. It covers mainly the exptl. and theor. discoveries of the past nine years (1997-2005). JO - Chemical Reviews VL - 106(9) ER - TY - JOUR AU - Guillarme, S. AU - Ple, K. AU - Banchet, A. AU - Liard, A. AU - Haudrechy, A. PY - 2006 TI - Alkynylation of Chiral Aldehydes: Alkoxy-, Amino-, and Thio-Substituted Aldehydes SP - 2355-403 KW - Aldehydes, chiral, alkynylation Alkoxyaldehydes Aminoaldehydes Thio-aldehydes JO - Chemical Reviews VL - 106(6) ER - TY - JOUR AU - Guillena, G. AU - Ramon, D.J. PY - 2006 TI - Enantioselective .a.-Heterofunctionalization of Carbonyl Compounds: Organocatalysis is the Simplest Approach SP - 1465-92 KW - Amino acids, .a.-, via organocatalysis Amino alcohols, .a.-, via organocatalysis Aziridines, via organocatalysis AB - A review discusses the application of enantioselective organocatalytic processes to the construction of chiral .a.-heterofunctionalized carbonyl compds., such as .a.-amino acids, .a.-amino alcs., aziridines, epoxides, 1,2-diols and .a.-sulfenylated, selenenylated and halogenated carbonyl derivs. Proline, imidazolidinone derivs., cinchona alkaloids and their ammonium salts, as well as Bronsted acid derivs., have been used as chiral catalysts for these purposes. JO - Tetrahedron: Asymmetry VL - 17 ER - TY - JOUR AU - Haider, N. PY - 2006 TI - Diazine Analogues of the Pyridocarbazole Alkaloids SP - 363-75 KW - Pyridocarbazole Alkaloids Carbazoles, diazine-fused Antitumor agents, diazine-fused carbazoles AB - A review. The pyrido[4,3-b]carbazole alkaloids, ellipticine and olivacine, were attracting considerable interest since many years due to their pronounced antitumor activity. Among the large no. of structural variations of these lead compds. which were performed in search of new agents with enhanced pharmacol. profiles, a remarkable proportion of work was devoted to the synthesis of diazine-fused carbazoles as aza analogs (in a broader sense) of the natural products. The present article will give a detailed overview of the literature from the past two decades in this field of medicinal heterocyclic chem. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Hajos, G. PY - 2006 TI - Recent Advances in the Area of Pyridodiazinium Systems Containing Bridgehead-Nitrogen Atom SP - 319-32 KW - Pyridodiazinium systems AB - A review of new synthetic pathways to pyrido[1,2-a]pyrimidinium, pyrido[1,2-a]pyrazinium, pyrido[1,2-c]pyrimidinium, and pyrido[1,2-b]pyridazinium systems and their partially satd. derivs. Reaction mechanisms of these ring closure methodologies are also discussed. Some representative further transformations of these ring systems are also summarized. Thus, alkylation of olates and thiolates, ring opening reactions, photochem. transformations and flash vacuum pyrolytic reactions are reviewed. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Hamashima, Y. AU - Sodeoka, M. PY - 2006 TI - Enantioselective Fluorination Reactions Catalyzed by Chiral Palladium Complexes SP - 1467-78 KW - Fluorination, enantioselective AB - A review. From the authors' chiral Pd enolate chem., efficient catalytic enantioselective fluorination reactions were developed. These reactions can be carried out in environmentally friendly alc. solvents without any precaution to exclude H2O and moisture. The reaction was found applicable to a wide range of active methine compds. including .b.-ketoesters, .b.-ketophosphonates, and other related compds. (up to 99% ee). Also, the authors succeeded in developing efficient fluorination reactions of 3-substituted oxindoles, which are found among many natural products. Sequential fluorination-solvolysis reaction of a 3-unsubstituted oxindole allowed monofluorination of an active methylene compd., and an optically active .a.-fluoroarylacetate was obtained JO - Synlett ER - TY - JOUR AU - Handy, S.T. AU - Zhang, Y. PY - 2005 TI - Approaches to the Synthesis of the Lamellarins and Related Natural Products. A Review SP - 411-45 KW - Lamellarins, synthesis AB - A review. Beyond their unusual arom. skeleton, the lamellarins have attracted attention due to their range of interesting and potentially useful biol. activities. The first of these activities noted was the cytotoxicity of the lamellarins to a no. of cancer cell lines. Following the initial report of the cytotoxicity of lamellarins I, K, and L toward P388 and A549 cell lines , a much more extensive study was undertaken by Quesada and coworkers. They examd. 13 different lamellarins against a panel of cancer cell lines, including multidrug resistant (MDR) variants. Synthetic routes to the lamellarins were reviewed. Although all of the routes have the advantage of being reasonably short (none are greater than 15 steps in length), the advances in the cross-coupling routes and their greater flexibility with respect to SAR studies appear to give them a practical advantage. This author's regioselective polycoupling approach retains this advantage and will further shorten the synthesis of the lamellarins and related mols., although addnl. work is clearly merited in order to achieve better yields and selectivities. Ultimately, the lessons learned from these efforts can ideally be extended to other non-pyrrole-based arom. products and greatly increase the utility of the regioselective polycoupling approach in natural products and pharmaceutical synthesis. JO - Organic Preparations and Procedures International VL - 37 ER - TY - JOUR AU - Hansen, E.C. AU - Lee, D. PY - 2006 TI - Search for Solutions to the Reactivity and Selectivity Problems in Enyne Metathesis SP - 509-19 KW - Enyne metathesis AB - Review. Enyne metathesis is a powerful carbon-carbon bond-forming reaction to generate 1,3-dienes from an alkyne and an alkene. Different from the diene and diyne metathesis, the enyne metathesis suffers from both regio- and stereoselectivity problems, yet there is no general soln. to these problems. This Account briefly describes the evolution of various new strategies and substrate platforms from these labs. to address the reactivity and selectivity issues in the enyne metathesis processes. JO - Accounts of Chemical Research VL - 39 ER - TY - BOOK AU - Hargreaves, J.S.J. AU - Jackson, S.D. AU - Webb, G. AU - Eds PY - 2006 BT - Isotopes in Heterogeneous Catalysis. [In: Catal. Sci. Ser.; 2006, 4] CY - London, U.K. PB - Imperial College Press SP - 291 KW - Isotopes, heterogeneous catalysis, book ER - TY - CHAP AU - Harrowven, D.C. AU - Sutton, B.J. PY - 2004 BT - Progress in Heterocyclic Chemistry, Volume 16 ED - Gribble, G.W. AU - Joule, J.A. AU - Eds CT - Radical Additions to Pyridines, Quinolines and Isoquinolines. CY - Oxford, UK PB - Elsevier SP - 475 KW - Pyridines, book Quinolines, book Isoquinolines, book ER - TY - JOUR AU - Hartwig, J.F. PY - 2006 TI - Discovery and Understanding of Transition-Metal-Catalyzed Aromatic Substitution Reactions SP - 1283-94 KW - Aromatics, substitution Cross-coupling, aryl halides with amines Cross-coupling, aryl sulfonates with amines Cross-coupling, aryl halides with alkoxides Cross-coupling, aryl halides with enolates Cross-coupling, aryl sulfonates with alkoxides Cross-coupling, aryl sulfonates with enolates AB - A review. This article presents studies on the development of cross-coupling reactions of aryl halides and sulfonates with amines, alkoxides, and various enolates. Emphasis is placed on the process of developing new catalysts with mechanistic information gained in the author's lab. JO - Synlett ER - TY - JOUR AU - Hawthorne, M.F. AU - Ramachandran, B.M. AU - Kennedy, R.D. AU - Knobler, C.B. PY - 2006 TI - Approaches to Rotary Molecular Motors SP - 1299-304 KW - Molecular motors, rotary AB - A review with 10 refs. on synthesis, structure, rotational potentials and DFT calcns. of redox-active disubstituted nickel dicarbollide complexes, serving as redox-activated mol. motors. The nickel disubstituted dicarbollide complexes were prepd. by complexation of [7,(8)-R-7,8-C2B9H10]2-, [3-R-7,8-C2B9H10]2-, [5,(6)-R-7,8-C2B9H10]2- and [5,6-R2-7,8-C2B9H10]2- with Ni(acac)3. Structure of the complexes was detd. by x-ray crystallog., studied by DFT calcns. of HOMO and LUMO orbitals and rotational potential. The Ni dicarbollides exhibit cisoid conformation in Ni4+ oxidn. state and different, mainly transoid or gauche conformations in Ni3+ oxidn. state, which was proved for pyrene substituents attached via short linker chain by their fluorescence in cisoid conformation. Transition between Ni4+ and Ni3+ oxidn. states may be effected by Fe3+ oxidn. and NaBH4 redn. Interest has recently intensified in the search for mol. motors and actuators capable of delivering useful work to nanodevices under the control of electrochem. or photochem. power sources. While many of these man-made mol. machines are designed to deliver rectilinear motion, very few are proposed for the controlled delivery of rotary motion on the time scale characteristic of intramol. rearrangements. The adaptation of commo-bis-dicarbollide metallacarborane structures to the possible design and synthesis of such rotary mol. motors is now under investigation. JO - Pure and Applied Chemistry VL - 78 ER - TY - JOUR AU - Heitbaum, M. AU - Glorius, F. AU - Escher, I. PY - 2006 TI - Asymmetric Heterogeneous Catalysis SP - 4732-62 KW - Heterogeneous catalysts, asymmetric AB - A review. Limited natural resources and an increasing demand for enantiomerically pure compds. render catalysis and esp. heterogeneous asym. catalysis a key technol. The field has rapidly advanced from the initial use of chiral biopolymers, such as silk, as a support for metal catalysts to the modern research areas. Mesoporous supports, noncovalent immobilization, metal-org. catalysts, chiral modifiers: many areas are rapidly evolving. This review shows that these catalysts have more to them than facile sepn. or recycling. Better activities can be obtained than with the homogeneous catalyst and novel, efficient reaction mechanisms can be employed. Esp. fascinating is the outlook for highly ordered metal-org. catalysts that might allow a rational design, synthesis, and the unequivocal structural characterization to give tailor-made catalysts. JO - Angewandte Chemie, International Edition VL - 45 ER - TY - CHAP AU - Hepworth, J.D. AU - Heron, B.M. PY - 2005 BT - Progress in Heterocyclic Chemistry ED - Gribble, G.W. AU - Joule, J.A. AU - Eds CT - Synthesis and Photochromic Properties of Naphthopyrans CY - Oxford, U.K. PB - Elsevier SP - 449 KW - Naphthopyrans, book VL - 17 ER - TY - JOUR AU - Hernandez, E. AU - Canales, E. AU - Gonzalez, E. AU - Soderquist, J.A. PY - 2006 TI - Asymmetric Synthesis with the Robust and Versatile 10-Substituted 9-Borabicyclo[3.3.2]Decanes: Homoallylic Amines from Aldimines SP - 1389-95 KW - Borabicyclo decanes Aldimines, allylboration Amines, homoallylic AB - A review of the asym. allylboration of N-H aldimines, generated from either N-trimethylsilyl or N-diisobutylalanyl precursors, with B-allyl-9-borabicyclo[3.3.2]decane is described. The desired homoallylic amines were obtained efficiently (60-90 %) and selectively (60-89% ee). A nonoxidative work-up procedure also was developed for this new method, which permits the recovery of the air-stable pseudoephedrine (PE) complex (50-70 %), which is conveniently converted back to B-allyl-9- borabicyclo[3.3.2]decane (98 %) with allylmagnesium bromide in ether for its reuse in the asym. allylboration process. Addnl. studies were conducted to better understand these processes and the origin of the obsd. enantioselectivity. JO - Pure and Applied Chemistry VL - 78 ER - TY - JOUR AU - Hosmane, N.S. AU - Maguire, J.A. PY - 2006 TI - Metallacarboranes: New Synthetic Strategies and Structural Patterns SP - 1333-40 KW - Metallacarboranes AB - A review. A summary of the latest results in the authors' labs. covering three areas of metallacarborane chem. is presented. The results of the controlled syntheses of oxide ion encapsulating lanthanacarboranes by the introduction of stoichiometric amts. of H2O during the syntheses and the structures of the resulting compds. are discussed. The scope and limitations of a general method for the synthesis of open-pentadienyl metallacarborane complexes are presented. The results of a systematic study of the reactions of the [2,n-(SiMe3)2-nido-2,n-C2B4H4]2- (n = 3, 4) with the late transition-metal salts MCl2 (M = Fe, Co, Ni) are discussed. JO - Pure and Applied Chemistry VL - 78 ER - TY - JOUR AU - Huang, J. AU - Hsung, R.P. PY - 2005 TI - Recent Advances in Stereoselective [4 + 3] Cycloaddition Reactions SP - 207-14 KW - Cycloaddition, [4+3] Heterocycles, 7-membered, synthesis AB - A review. The title research, a convenient entry into 7-membered rings, of several groups over the 1999-2003 period is reviewed with commentary. The mechanism, regio-, stereo-, and enantioselectivity of inter- and intramol. [4 + 3] oxyallyl [CH2=C(OR)CH2+] cycloaddns. and their applications are discussed. JO - Chemtracts VL - 18 ER - TY - JOUR AU - Huang, P.-Q. PY - 2006 TI - Asymmetric Synthesis of Hydroxylated Pyrrolidines, Piperidines, and Related Bioactive Compounds: From N-Acyliminium Chemistry to N-.a.-Carbanion Chemistry SP - 1133-49 KW - Pyrrolidines, hydroxylated Piperidines, hydroxylated AB - A review. This account describes our recent studies on the development of chiral nonracemic cyclic imide-based synthetic methodol. and the complementary N-.a.-carbanion synthon-based synthetic methodol. for the asym. syntheses of naturally occurring or pharmaceutically interesting hydroxylated pyrrolidines, 2-pyrrolidinones, .b.-hydroxy-?-amino acids, and their higher homologs as well as isoindolin-1-ones, tetramic acid, and tetramate derivs. JO - Synlett ER - TY - JOUR AU - Hyeon, J.-Y. AU - Gottfriedsen, J. AU - Edelmann, F.T. PY - 2005 TI - Lanthanides and Actinides: Annual Survey of Their Organometallic Chemistry Covering the Year 2000 SP - 2787-844 KW - Lanthanides, organometallic Actinides, organometallic AB - A review. The organometallic chem. of lanthanides and actinides covered in the literature for 2000 is reviewed. Cyclopentadienyl and cyclooctatetraenyl complexes are emphasized. JO - Coordination Chemistry Reviews VL - 249 ER - TY - JOUR AU - Ishiyama, T. AU - Miyaura, N. PY - 2006 TI - Iridium-Catalyzed Borylation of Arenes and Heteroarenes via C-H Activation SP - 1369-75 KW - Aromatics, borylation AB - A review of direct C-H borylation of arom. compds. catalyzed by a transition-metal complex is presented and is as an economical protocol for the synthesis of arom. B derivs. Ir complexes generated from Ir(I) precursors and 2,2'-bipyridine ligands efficiently catalyzed the reactions of arenes and heteroarenes with bis(pinacolato)diboron or pinacolborane to produce a variety of aryl- and heteroarylboron compds. The catalytic cycle involves the formation of a tris(boryl)iridium(III) species and its oxidative addn. to an arom. C-H bond. JO - Pure and Applied Chemistry VL - 78 ER - TY - JOUR AU - Itami, K. AU - Yoshida, J.-i. PY - 2006 TI - Platform Synthesis: A Useful Strategy for Rapid and Systematic Generation of Molecular Diversity SP - 3966-74 KW - Platform synthesis Combinatorial chemistry AB - A review. Emergence of library-based approaches have changed the way of developing new functional mols. in materials science and pharmaceutical science. Therefore, reliable methods for rapid and systematic generation of functional mols. are highly called for in this field. Thus, the concept of platform synthesis as a useful strategy for generating mol. diversity is described. This simple yet powerful strategy realizes the synthesis of a no. of interesting multifunctional mols., such as multisubstituted olefins, in a programmable and diversity-oriented format. As well as applications to the synthesis of pharmaceutically important mols., such as tamoxifen and CDP840, applications to materials science, which have led to the discovery of interesting fluorescent materials and properties, are also described. JO - Chemistry--A European Journal VL - 12 ER - TY - JOUR AU - Itsikson, N.A. AU - Zyryanov, G.V. AU - Chupakhin, O.N. AU - Matern, A.I. PY - 2005 TI - Heteroditopic Receptors SP - 747-55 KW - Heteroditopic receptors Complexing agents AB - A review. Data on heteroditopic receptors, an important class of complexing agents, are surveyed. Attention was focused on the synthesis of the ligands and anal. of their binding properties. The influence of structural features on the properties of such systems was investigated. The bibliog. included 49 refs. JO - Russian Chemical Reviews VL - 74 ER - TY - JOUR AU - Jabbour, A. AU - Smoum, R. AU - Takrouri, K. AU - Shalom, E. AU - Zaks, B. AU - Steinberg, D. AU - Rubinstein, A. AU - Goldberg, I. AU - Katzhendler, J. AU - Srebnik, M. PY - 2006 TI - Pharmacologically Active Boranes SP - 1425-53 KW - Cyanoboranes, alkyldimethylamine Cyanoboranes, hydroxylalkyldimethylamine AB - A review of novel methods describing the prepn. of alkyldimethylamine cyanoboranes and .b.-hydroxylalkyldimethylamine cyanoboranes by C-lithiation of trimethylamine cyanoboranes followed by reaction with alkyl halides, aldehydes, and ketones is presented. Lithiation of the monobromo derivs. of amine cyanoboranes gave the 1st examples of diborane derivs. of amine cyanoboranes. Bromo derivs. of amine cyanoboranes and amine carboxyboranes were synthesized by new simple and efficient methods. Amine fluorocyanoboranes and amine fluorocarboxyboranes, new classes of compds., were prepd. from the bromo precursors by F/Br exchange using fluorinating reagents such as AgF and Et3N·3HF. Eight different derivs. of oxazaborolidines were synthesized and evaluated for their affect on Streptococcus mutans viability, adhesion, and biofilm formation using 3[H]-thymidine labeled bacteria, and fluorescent stained bacteria. This is the 1st reported antibacterial activity of this class of compds. The minimal inhibitory concn. (MIC) values ranged from 0.26 to 10 mM. Structure-activity relation was obsd. The B-Bu moiety of the oxazaborolidines contributed an anti-adhesion effect for all derivs., while its effect diminished when the B atom was incorporated in a fused heterocyclic ring. The B-Ph group induced bacterial adhesion in all tested compds. In a sep. study for boronated saccahrides and enzymic inhibition, the complex formation between N-butylboronic acid and monosaccharides were studied by 1H, 13C, and 13B NMR spectroscopy and gas chromatog.-mass spectrometry (GC-MS). Then, boronic acid compds. with protease inhibition properties were prepd. The effect of added mono-, di-, and polysaccharides on the inhibitory activity of these compds. was studied. K organotrifluoroborates are reversible competitive inhibitors of .a.-chymotrypsin and trypsin. Based on 19F NMR, it was speculated that they inactivate the enzymes as a result of the formation of H bonds between F atoms of the inhibitors and the serine protease. JO - Pure and Applied Chemistry VL - 78 ER - TY - JOUR AU - Jaekel, C. AU - Paciello, R. PY - 2006 TI - High-Throughput and Parallel Screening Methods in Asymmetric Hydrogenation SP - 2912-42 KW - Catalysts, hydrogenation, screening AB - A review discusses the use of high-throughput and parallel methods for the screening of catalysts, particularly catalysts for enantioselective hydrogenation reactions. JO - Chemical Reviews VL - 106(7) ER - TY - JOUR AU - Jaime, C. AU - de Federico, M. PY - 2006 TI - Computational Studies on Two Supramolecular Structures: Cyclodextrins and Rotaxanes SP - 731-43 KW - Cyclodextrins, computational chemistry Rotaxanes, computational chemistry AB - A review. Supramol. structures are formed by holding two or more mols. without covalent bonds. Although rotaxanes are not supramol. species but real mols., the interactions existing between the fragments composing rotaxanes are of the same type of those in supramol. species. Rotaxanes and cyclodextrins are the two structures being considered in this review. The contribution of the authors in the study of these two classes of compds. by computational techniques will be presented. Aspects like geometry of the complex (bimodality), estn. of assocn. consts., conformational changes produced by the complexation, enantiodifferentiation, changes in the mol. reactivity, formation of aggregates, shuttling of the rotaxanes, and the energetic aspects and the geometry of cyclodiastereomeric rotaxanes are also discussed. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Jankowski, S. AU - Huben, K. PY - 2006 TI - 2-Phospha- and 2,3-Oxaphosphabicyclo[2.2.2]Octenes - Synthesis and Fragmentation to Low-Coordinated Species SP - 79-92 KW - Octenes, phosphabicyclo- Octenes, oxaphosphabicyclo- AB - A review. The 2-phosphabicyclo[2.2.2]octene and 2,3- oxaphosphabicyclo[2.2.2]octene systems undergo fragmentation in inert solvents on heating, or by UV-irradn. at room or low temp. The fragmentation is of significance because it leads to the extrusion of low-coordinated species Y-P(X)O (Y = RO, R2N, Aryl; X = O, S, CH2), which are very effective phosphorylating agents. This review covers different aspects of the 2-phosphabicyclo[2.2.2]octene and 2,3- oxaphosphabicyclo[2.2.2]octene derivs. The 1st part is focused on their synthesis and structure. The reactivity of 2,3-oxaphosphabicyclooctenes involving rearrangement and fragmentation with release of the bridging P-O unit including mechanistic studies is described in the next part. The last part of the review is dedicated to the practical aspects of the use these compds. as phosphorylating agents. JO - Current Organic Chemistry VL - 10 ER - TY - CHAP AU - Jiangnan, P. AU - et al. PY - 2005 BT - Alkaloids: Chemistry and Biology. ED - Cordell, G.A. AU - Ed CT - The Marine Bromotyrosine Derivatives CY - San Diego, CA PB - Elsevier SP - 282 KW - Alkaloids, book ER - TY - JOUR AU - Kas'yan, L.I. AU - Kas'yan, A.O. AU - Okovityi, S.I. PY - 2006 TI - Reactions of Alicyclic Epoxy Compounds with Oxygen-Centered Nucleophiles SP - 307-37 KW - Epoxy compounds, alicyclic AB - This review analyzes the reactions of alicyclic epoxy compds. with oxygen-contg. nucleophiles (alcs., water, and org. acids), describes biol. active products of these reactions, and discusses their mechanisms and results of their simulation by quantum-chem. methods. The regio-and stereoselectivity of nucleophilic reactions of epoxy compds. and the activation of epoxy ring by achiral and chiral catalysts are also considered. JO - Russian Journal of Organic Chemistry VL - 42 ER - TY - JOUR AU - Katsara, M. AU - Tselios, T. AU - Deraos, S. AU - Deraos, G. AU - Matsoukas, M.-T. AU - Lazoura, E. AU - Matsoukas, J. AU - Apostolopoulos, V. PY - 2006 TI - Round and Round We Go: Cyclic Peptides in Disease SP - 2221-32 KW - Cyclic peptides, therapeutic agents AB - A review. Cyclic peptides have made crucial contributions to the treatment of certain diseases. Vancomycin, cyclosporin, the echinocandins and bleomycin are well-known cyclic peptides. Cyclic peptides, compared to linear peptides, have been considered to have greater potential as therapeutic agents due to their increased chem. and enzymic stability, receptor selectively, and improved pharmacodynamic properties. They have been used as synthetic immunogens, transmembrane ion channels, antigens for herpes simplex virus, potential immunotherapeutic vaccines for diabetes and exptl. autoimmune encephalomyelitis - an animal model of multiple sclerosis, as inhibitors against .a.-amylase and as protein stabilizers. Herein, the authors review important cyclic peptides as therapeutic agents in disease treatment. JO - Current Medicinal Chemistry VL - 13 ER - TY - JOUR AU - Keglevich, G. PY - 2006 TI - 6-Membered P-Heterocycles: 1,2-Dihydro-, 1,2,3,6-Tetrahydro- and 1,2,3,4,5,6-Hexahydrophosphinine 1-Oxides SP - 93-111 KW - Heterocycles, 6-membered, P- Hexahydrophosphinine oxides AB - A review. The members of a logically built P-heterocyclic family are discussed systematically to show a dynamically developing discipline of organophosphorus chem. Dichlorocyclopropanation of 2,5-dihydro-1H- phosphole oxides led to 3-phosphabicyclo[3.1.0]hexane 3-oxides that are useful intermediates for the synthesis of ring expanded products, such as 1,2-dihydrophosphinine oxides and 3-alkoxy-1,2,3,6-tetrahydrophosphinine oxides. Catalytic hydrogenation of 1,2-dihydrophosphinine oxides gave 1,2,3,4,5,6-hexahydrophosphinine oxides. Selective redn. of the .a.,.b.-double-bond of 1,2-dihydrophosphinine oxides via hydroboration led to 1,2,3,6-tetrahydrophosphinine oxides. Michael addn. of >P(O)H species to the electron-poor double-bond of 1,2- dihydrophosphinine oxides afforded 1,2,3,6-tetrahydrophosphinine oxides with exocyclic P-function in position 3. Hydrogenation of these P-heterocycles led to the corresponding hexahydrophosphinine oxides. Stereostructure and conformation of the tetra- and hexahydrophosphinine oxides were elucidated by stereospecific NMR couplings and/or quantum chem. calcns. After deoxygenation, some of the above P-heterocycles were suitable P-ligands in transition metal complexes. The 1,2-dihydrophosphinine oxides were also useful in the synthesis of arom. phosphinines, phosphepine derivs. and phosphabicyclo[2.2.2]octene oxides, as well as heterocyclic .b.-oxophosphoranes. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Kim, B.J. AU - Sasaki, T. PY - 2006 TI - Recent Progress in the Synthesis of Artemisinin and its Derivatives SP - 1-80 KW - Artemisinin, antimalarial agent Artemisinin, anticancer agent Antimalarial agent, artemisinin Anticancer agent, artemisinin Endoperoxides AB - A review on synthetic approaches to artemisin and related endoperoxides its dihydro, carba, deoxo, fluorocarba, and aza derivs. via coupling reactions and from artemisinic acid is given. An appendix lists antimalarial and anticancer activities of artemisin analogs. JO - Organic Preparations and Procedures International VL - 38 ER - TY - JOUR AU - Kimball, D.B. AU - Silks, L.A., III PY - 2006 TI - Current Progress in the Acetate/Methyl Ketone Aldol Reaction SP - 1975-92 KW - Acetate/methyl ketone aldol reaction AB - A review. The aldol reaction of acetate and Me ketone-based donors with aldehyde acceptors is reviewed. Emphasis is placed on major advances reported in the last 10-15 years. Several methods for inducing chirality at the newly formed stereogenic center are discussed, including popular alternate methods for equiv. syntheses. Different methods for stereospecific synthesis are compared in terms of yield, selectivity, ease of synthesis, and applicability to both small mol. and large macrolide prodn. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Kirschning, A. AU - Solodenko, W. AU - Mennecke, K. PY - 2006 TI - Combining Enabling Techniques in Organic Synthesis: Continuous Flow Processes with Heterogenized Catalysts SP - 5972-90 KW - Continuous flow processes Heterogenized catalysts Microwaves, with other techniques AB - This review describes enabling techniques (solid-phase assisted synthesis, new reactor design, microwave irradn. and new solvents) in org. chem. and emphasizes the combination of several of them for creating new synthetic technol. platforms. Particular focus is put on the combination of immobilized catalysts as well as biocatalysts with continuous flow processes. In this context, the PASSflow continuous flow technique fulfils both chem. as well as chem. engineering requirements. It combines reactor design with optimized, monolithic solid phases as well as reversible immobilization techniques for performing small as well as large scale synthesis with heterogenized catalysts under continuous flow conditions. JO - Chemistry--A European Journal VL - 12 ER - TY - BOOK AU - Klok, H.-A. AU - Schlaad, H. AU - Eds PY - 2006 BT - Peptide Hybrid Polymers. [In: Adv. Polym. Sci.; 2006, 202] CY - Berlin, Germany PB - Springer SP - 160 KW - Peptide hybrid polymers, book ER - TY - CHAP AU - Kobayashi, J.i. AU - Morita, H. PY - 2005 BT - Alkaloids: Chemistry and Biology ED - Cordell, G.A. AU - Ed CT - The Lycopodium Alkaloids CY - San Diego, CA PB - Elsevier SP - 282 KW - Alkaloids, book ER - TY - JOUR AU - Kobayashi, S. AU - Ogawa, C. PY - 2006 TI - New Entries to Water-Compatible Lewis Acids SP - 5954-60 KW - Lewis acids, water-stable AB - A review. Lewis acid catalysis has attracted much attention in org. synthesis as it often affords access to unique reactivity and selectivity under mild conditions. Although various kinds of Lewis acids have been developed and applied in industry, these Lewis acids must be generally used under strictly anhyd. conditions, as the presence of even a small amt. of water interferes with the reactions due to preferential reaction of the Lewis acids with water rather than the substrates. In contrast to this, rare earth and other metal complexes have been found to be water-compatible. Furthermore, Bi(OTf)3- and Ga(OTf)3-basic ligand complexes have also been found to be stable in water, and have been used as water-compatible Lewis acids. This application is particularly significant, as Bi(OTf)3 and Ga(OTf)3 themselves are unstable in the presence of water, but are stabilized by the basic ligands. This observation has led to the development of a new approach to Lewis acid catalysis in which Lewis acids that are generally unstable in the presence of water are rendered amenable to aq. systems when combined with basic ligands. In particular, the use of chiral basic ligands leading to new types of water-compatible chiral Lewis acids may enable a wide range of asym. catalysis in aq. media. JO - Chemistry--A European Journal VL - 12 ER - TY - JOUR AU - Koldobskii, G.I. PY - 2006 TI - Strategies and Prospects in Functionalization of Tetrazoles SP - 469-86 KW - Tetrazoles AB - The review summarizes the methods of functionalization of tetrazoles, which were reported from 2001 to mid 2005, and analyzes main strategies in the development of this field of tetrazole chem. JO - Russian Journal of Organic Chemistry VL - 42 ER - TY - JOUR AU - Koval, I.V. PY - 2006 TI - Heterocyclization Reactions Involving Thiols SP - 625-51 KW - Thiols, heterocyclization Heterocycles, S-, synthesis AB - A review. Information on the syntheses of S-contg. heterocycles involving thiols is systematized and generalized. Data on biol. action of some among these systems are mentioned. JO - Russian Journal of Organic Chemistry VL - 42 ER - TY - JOUR AU - Kravchenko, A.N. AU - Chikunov, I.E. PY - 2006 TI - Chemistry of Ureido Carboxylic and Ureylene Dicarboxylic Acids SP - 191-206 KW - Carboxylic acids, ureido Dicarboxylic acids, ureylene AB - A review which presents a comparative anal. of procedures for the synthesis of ureido carboxylic and ureylene dicarboxylic acids. Chem. transformations of these compds. are summarized. New fields of application of ureido carboxylic acids in the synthesis of chiral, diastereomeric and enantiomerically pure N-carboxyalkylglycolurils are considered. The bibliog. includes 129 refs. JO - Russian Chemical Reviews VL - 75 ER - TY - JOUR AU - Kresge, A.J. PY - 2005 TI - Time-Resolved Resonance Raman Observation of the 2-Fluorenylnitrenium Ion Reaction with Guanosine to Form a C8 Intermediate SP - 234-5 KW - Guanosine, with 2-fluorenylnitrenium ion AB - A review. The title research of P.Y. Chan, et al., (2005) is reviewed with commentary. JO - Chemtracts VL - 18 ER - TY - JOUR AU - Kulikov, O.V. AU - Pavlovsky, V.I. AU - Andronati, S.A. PY - 2005 TI - Dibenzotetraazamacroheterocycles: Synthesis and Properties SP - 1447-75 KW - Dibenzotetraazamacroheterocycles AB - A review. Data on the synthesis, complexing ability, practical applications, and biol. activity of dibenzo tetraaza macro-heterocycles of the azacrown ether, amide, and azomethinedibenzotetraazacycloalkane types and also dibenzo tetraaza macro-heterocycles contg. amide and azomethine fragments are classified and analyzed. JO - Chemistry of Heterocyclic Compounds VL - 41(12) ER - TY - JOUR AU - Landorf, C.W. AU - Haley, M.M. PY - 2006 TI - Recent Advances in Metallabenzene Chemistry SP - 3914-36 KW - Metallabenzenes AB - A review. Chem. chameleons - with regard to properties normally assocd. with aromaticity - aptly describe metallabenzenes, as they exhibit delocalized bonding, possess downfield 1H NMR chem. shifts, and form (arene)metal coordination complexes, but are often distinctly nonplanar, undergo [4+2] cycloaddn. reactions, and rearrange to form cyclopentadiene complexes. This review describes the synthesis, chem., and unusual phys. properties of metallabenzenes contg. osmium, ruthenium, iridium, rhodium and platinum. JO - Angewandte Chemie, International Edition VL - 45 ER - TY - JOUR AU - Le Floch, P. PY - 2006 TI - Phosphaalkene, Phospholyl and Phosphinine Ligands: New Tools in Coordination Chemistry and Catalysis SP - 627-81 KW - Phosphaalkene ligands Phospholyl ligands Phosphinine Ligands AB - A review. This review covers recent achievements in the area of low coordinate phosphorus ligands featuring P:C double bonds such as phosphaalkenes, phospholide-based complexes and phosphinines. The most significant developments are presented and discussed for each class of ligands. Particular attention has been paid to the use of these new systems as ligands in homogeneous catalysis. JO - Coordination Chemistry Reviews VL - 250 ER - TY - JOUR AU - Leigh, D.A. AU - Perez, E.M. PY - 2006 TI - Dynamic Chirality: Molecular Shuttles and Motors SP - 185-208 KW - Dynamic chirality Molecular machines AB - A review. To appreciate the technol. potential of controlled mol.-level motion one only has to consider that it lies at the heart of virtually every biol. process. When the authors learn how to build synthetic mol. motors and machines that can interface their effects directly with other mol.-level sub-structures and the outside world it will add a new dimension to functional mol. and materials design. In this review the authors discuss both the influence of chirality on the design of mol. level machines and, in turn, how mol. level machines can control the expression of chirality of a phys. response to an inherently achiral stimulus. JO - Topics in Current Chemistry VL - 265 ER - TY - JOUR AU - Len, C. AU - Mackenzie, G. PY - 2006 TI - Synthesis of 2',3'-Didehydro-2',3'-Dideoxynucleosides Having Variations at Either or Both of the 2'- and 3'-Positions SP - 9085-107 KW - Didehydrodideoxynucleosides AB - Review on the synthesis of 2',3'-didehydro-2',3'-dideoxynucleosides having variations at either or both of the 2'- and 3'-positions. JO - Tetrahedron VL - 62 ER - TY - JOUR AU - Lenoir, D. PY - 2006 TI - Selective Oxidation of Organic Compounds -Sustainable Catalytic Reactions with Oxygen and Without Transition Metals? SP - 3206-10 KW - Oxidation, without transition metals AB - A review. Alcs. can be oxidized with oxygen and without transition-metal complexes. Conventional methods are compared with new catalytic variants developed for this reaction and for the complete oxidn. of pollutants with regard to sustainability. JO - Angewandte Chemie, International Edition VL - 45 ER - TY - JOUR AU - Lewis, S.E. PY - 2006 TI - Recent Advances in the Chemistry of Macroline, Sarpagine and Ajmaline-Related Indole Alkaloids SP - 8655-81 KW - Indole alkaloids AB - A review. A huge variety of indole alkaloids are known, many of which have been submitted to total synthesis. This review concerns the chem. of indole alkaloids related to macroline, sarpagine, and ajmaline. The chem. detailed herein shows that considerable advances have been recently been made in the field of sarpagine/macroline/ajmaline indole alkaloids since the field was last reviewed. The Pictet-Spengler reaction remains a key strategic transformation for the synthesis of mols. of this class, as evidenced by the work of Cook, Bailey and Craig. Nevertheless, a diverse array of other reaction classes have been deployed to access the targets in question. In particular, Cook's use of a common late-stage tetracyclic intermediate has allowed access to a large variety of natural products by use of varied transformations for the final elaborations. It is anticipated that further advances in the chem. of sarpagine/macroline/ajmaline indole alkaloids will be reported in due course by many of the labs. from which the work reviewed here originated. JO - Tetrahedron VL - 62 ER - TY - JOUR AU - Li, Y. AU - Kusari, U. AU - Carroll, P.J. AU - Bradley, M.G. AU - Sneddon, L.G. PY - 2006 TI - Polyborane Reactions in Ionic Liquids SP - 1349-55 KW - Polyboranes, in ionic liquids Alkenes, hydroboration AB - A review with 19 refs. on reactivity of borane cage compds. with alkenes and alkynes in ionic liqs. Catalyst-free decaborane reactions in ionic liqs., hydroboration of alkenes and insertion of alkynes, provide a facile and high-yield route to diverse functionalized o-carborane derivs. In contrast to reactions that have been obsd. in traditional org. solvents, decaborane olefin-hydroboration and alkyne-insertion reactions proceed in ionic liq. (IL) solvents without the need of a catalyst. Hydroboration of alkenes by B10H14 in Bmim-BF4 in biphasic conditions gives 6-substituted decaboranes, the reaction being tolerant to important functional groups, such as ester groups. On the contrary, terminal and internal alkynes undergo direct insertion into the decaborane(14) cage in ionic liqs., affording o-carboranes with wide range of functional substituents in one-step base-free process. Combination of both alkene hydroboration and alkyne insertion affords a easy synthetic pathway to 1,2,3-trisubstituted o-carboranes, which are important intermediates for boron neutron capture therapy agents. Lower cage boranes undergo facile dehydrocondensation in ionic liqs. at elevated temps., giving access to higher cage boranes, as illustrated by the synthesis of n-B18H22 from 4-Me2S-B9H13 in Bmim-Cl at 130° for 2 h. JO - Pure and Applied Chemistry VL - 78 ER - TY - JOUR AU - Liljeblad, A. AU - Kanerva, L.T. PY - 2006 TI - Biocatalysis as a Profound Tool in the Preparation of Highly Enantiopure .b.-Amino Acids SP - 5831-54 KW - Amino acids, .b.-, biocatalysis AB - A review. Enzymic kinetic resolns. and other biotransformations are discussed. JO - Tetrahedron VL - 62 ER - TY - JOUR AU - Litvinov, V.P. PY - 2006 TI - Advances in the Chemistry of Naphthyridines SP - 189-300 KW - Naphthyridines AB - A review in which an anal. is made of the synthesis and properties of 6 isomeric heterocyclic systems contg. 2 fused pyridine rings with different mutual arrangements of N atoms, naphthyridines (pyridopyridines, diazanaphthalenes). JO - Advances in Heterocyclic Chemistry ER - TY - JOUR AU - Liu, J.-K. PY - 2006 TI - Natural Terphenyls: Developments since 1877 SP - 2209-23 KW - Terphenyls, natural AB - A review on the isolation, structure, biol. activity, transformation and total synthesis of terphenyl derivs. from nature. JO - Chemical Reviews VL - 106(6) ER - TY - JOUR AU - Liu, Y. AU - Zhang, S. AU - Abreu, P.J.M. PY - 2006 TI - Heterocyclic Terpenes. Linear Furano- and Pyrroloterpenoids SP - 630-51 KW - Terpenes, heterocyclic Furanoterpenoids Pyrroloterpenoids AB - A review. The emphasis of this review is on linear furano- and pyrroloterpenoids, together with their relevant biol. activities, source organisms and country of origin. First total syntheses that lead to the revision of structures or stereochemistries were included, and 206 refs. are cited. JO - Natural Product Reports VL - 23 ER - TY - JOUR AU - Lopez, R. AU - Menendez, M.I. AU - Diaz, N. AU - Suarez, D. AU - Campomanes, P. AU - Ardura, D. AU - Sordo, T.L. PY - 2006 TI - Theoretical Studies on the Ring Opening of .b.-Lactams: Processes in Solution and in Enzymatic Media SP - 805-21 KW - Lactams, .b.-, cleavage AB - A review. Herein the authors present an overview of the theor. studies on the cleavage of the .b.-lactam C-N bond in aq. soln. and in enzymic media. The authors discuss first the alk. hydrolysis of .b.-lactams that was studied thoroughly by semiempirical, ab initio, and d. functional calcns., while solvent effects were typically included using a discrete and/or continuum representation of solvent. These computational studies study the origin of the energy barrier, the structure and stability of tetrahedral intermediates, substituent effects, catalysis by transition metals such as Zn(II) and Cu(II), etc. Other recent articles were devoted to the anal. of the acidic and neutral hydrolysis/alcoholysis of .b.-lactams as well as their ozonolysis. The authors also review theor. studies that describe the ammonolysis/aminolysis of monocyclic and bicyclic .b.-lactams using d. functional calcns. combined with a solvent continuum model. The aminolysis reaction between the lysine 199 residue of Human Serum Albumin and benzylpenicillin is also revised. The second part of this review concs. on the .b.-lactam ring opening catalyzed by the penicillin recognizing proteins family of bacterial enzymes, which includes both serine-proteases and zinc-proteases. For the serine proteases (.b.-lactamases and penicillin binding proteins), quantum chem. optimizations on cluster models of their active sites and JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Ma, J.-A. PY - 2006 TI - Catalytic Asymmetric Synthesis of .a.- and .b.-Amino Phosphonic Acid Derivatives SP - 630-6 KW - Amino phosphonic acid derivatives AB - A review. Catalytic asym. reactions provide one of the most powerful and economical synthetic approaches to a variety of enantiomerically enriched compds. As being analogs of the corresponding .a.- and .b.-amino acids, optically active .a.- and .b.-amino phosphonic acid derivs. have found widespread use in medicinal chem. and the pharmaceutical sciences. Using catalytic amts. of chiral materials, asym. synthesis of enantiomerically enriched .a.- and .b.-amino phosphonates has been a subject of growing interest. This tutorial review contains a compilation of the catalytic asym. synthetic methods developed to date and highlights their utility for obtaining these target compds. JO - Chemical Society Reviews VL - 35 ER - TY - JOUR AU - Maezaki, N. AU - Kojima, N. AU - Tanaka, T. PY - 2006 TI - Systematic Synthesis of Diastereomeric THF Ring Cores and Total Synthesis of Anti-Tumor Annonaceous Acetogenins SP - 993-1003 KW - Anti-tumor agents, Annonaceous acetogenins Polytetrahydrofuran ring core AB - A review. We have developed a systematic synthesis of the poly-THF ring cores of anti-tumor Annonaceous acetogenins by utilizing asym. alkynylation and subsequent stereodivergent THF ring formation as key steps. The asym. alkynylation of .a.-oxyaldehyde and .a.-tetrahydrofuranic aldehyde with an (S)-3-butyne-1,2-diol deriv. proceeded in good yield with very high diastereoselectivity. These adducts were converted into mono- and bis-THF cores by two different methods involving one-pot THF ring formation. The total syntheses of murisolin, 16,19-cis-murisolin, and longimicin D, which show cytotoxic activity against the human tumor cell, were accomplished by applying this methodol. JO - Synlett ER - TY - JOUR AU - Maifeld, S.V. AU - Lee, D. PY - 2006 TI - Progress Toward the Total Synthesis of Guanacastepene A SP - 1623-44 KW - Guanacastepene A AB - A review. Guanacastepene A, the leading member of a structurally diverse family of diterpene natural products, was isolated from the exts. of an unidentified fungus. The discovery of its potent antibiotic activity as well as its previously unreported tricyclic architecture render guanacastepene A an attractive and formidable target for total synthesis. Specifically, guanacastepene A's synthetic challenges include 2 ring-junction quaternary Me groups and a novel 5-7-6 tricyclic carbon skeleton possessing a dense array of oxygen and unsatd. functionalities. In this account, we will discuss our motivation and efforts toward the total synthesis of guanacastepene A as well as highlight the contributions from the synthetic community toward this pursuit. JO - Synlett ER - TY - JOUR AU - Mas-Balleste, R. AU - Que, L., Jr. PY - 2006 TI - Chemistry: Targeting Specific C-H Bonds for Oxidation SP - 1885-6 KW - C-H bonds, selective oxygenation Hydrogen bonds in molecular recognition AB - Catalysts mimic substrate orientation in oxidn. of C-H bonds as enzymes selectivity in activities. JO - Science VL - 312(5782) ER - TY - JOUR AU - Mascavage, L.M. AU - Wilson, M.L. AU - Dalton, D.R. PY - 2006 TI - Syntheses of Morphine and Codeine (1992-2002): Templates for Exploration of Synthetic Tools SP - 99-120 KW - Morphine synthesis Codeine synthesis AB - A review. Morphine and its O-methylated analog codeine, analgesic alkaloids of the opium poppy (Papaver Somniferium), were targets of org. chemists engaged in synthetic activities for at least half a century. The "first" (Gates) and "most efficient" (Rice) syntheses of morphine and codeine are well known and were reviewed and analyzed extensively numerous times. However, syntheses of the same two alkaloids that were reported since 1992 and which were used as devices to advance the art of org. synthesis are not as widely recognized and they have not been as thoroughly reviewed. Here they are analyzed in the spirit of the use of these two compds. as templates. Further, since both racemic and enantiospecific syntheses are important and since all 8 approaches (since 1992) are sufficiently different so as to warrant more than superficial examn., they are all considered. JO - Current Organic Synthesis VL - 3 ER - TY - JOUR AU - Matyus, P. AU - Elias, O. AU - Tapolcsanyi, P. AU - Polonka-Balint, A. AU - Halasz-Dajka, B. PY - 2006 TI - Ring-Closure Reactions of Ortho-Vinyl-Tert-Anilines and (Di)Aza-Heterocyclic Analogues via the Tert-Amino Effect. Recent Developments SP - 2625-39 KW - Anilines, tert-amino effect Tetrahydropyridine, fused, synthesis AB - A review. One version of the tert-amino effect operating in tert-anilines possessing an ortho-vinyl substituent affords a fused tetrahydropyridine ring by an isomerization process with the formation of a new carbon-carbon bond between the vinyl and tert-amino moieties. Since its discovery in 1984, this type of cyclization was efficiently used for the construction of fused-ring systems. However, it was found that the electron-deficient heterocyclic analogs of tert-anilines, such as diazines, may undergo isomerization at considerably lower reaction rates and, as a consequence, their reactions may require harsh conditions. Recent synthetic studies have indicated that the rate and yield may be improved by incorporating the .b.-vinylic carbon atom into an electron-deficient ring and/or buttressing the tert-amino group, and/or performing the reaction by means of microwave irradn. This review describes relatively recent synthetic transformations involving this type of tert-amino effect and devotes special attention to structure-reactivity relationships including regio- and stereo-chem. aspects. JO - Synthesis ER - TY - JOUR AU - McDowell, S.A.C. PY - 2006 TI - Studies of Neutral Rare-Gas Compounds and Their Non-Covalent Interactions with Other Molecules SP - 791-803 KW - Rare gas compounds AB - A review. The main focus of this review is a new class of neutral mols. contg. chem. bonded rare gas atoms. These compds. are given by the general formula HRgX, where Rg denotes a rare gas atom and X denotes an atom or group of atoms having high electron affinity. They are usually produced by photolysis of a HX precursor in low temp. rare-gas matrixes. These novel compds. are highly polar and form weakly bound metastable complexes with other mols. via noncovalent interactions. In this review, the authors discuss theor. studies of the structure, bonding, properties and factors influencing the energetic stability of these rare-gas species, the prepn. and vibrational spectroscopy of these mols. and some theor. approaches to understanding the nature of these mols., with exptl. studies discussed where appropriate. The complexes formed by the rare-gas compds. exhibit unusual structural and spectroscopic features, which are also discussed in the review. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - McGhee, A.M. AU - Procter, D.J. PY - 2006 TI - Radical Chemistry on Solid Support SP - 93-134 KW - Radical reactions, solid support AB - A review which covers recent advances in the field of radical chem. on solid phase. Intermol. processes using both immobilized radicals with soln.-phase acceptors and immobilized acceptors with radicals in soln. are discussed, as are radical cyclization reactions on polymer supports. Progress in the development of solid-phase asym. radical processes and the design of linkers cleaved by radical processes are also discussed. JO - Topics in Current Chemistry VL - 264 ER - TY - JOUR AU - Merino, P. PY - 2006 TI - Heterocyclic Nucleosides: Chemical Synthesis and Biological Properties SP - 539-45 KW - Heterocyclic nucleosides AB - A review with 18 refs. This update covers the literature for 2002 and 2003 dealing with the main topic of the previous review entitled Heterocyclic nucleosides. Chem. synthesis and biol. properties and published in Curr. Med. Chem.-AIA, 2002, 1, 389. As in the first review, the papers in this survey are grouped by the type of the heterocyclic system that acts as a spacer between the hydroxymethyl group and the base moiety. JO - Current Medicinal Chemistry VL - 13 ER - TY - JOUR AU - Mezailles, N. AU - Le Floch, P. PY - 2006 TI - The Chemistry of Phosphinines: Syntheses, Coordination Chemistry and Catalysis SP - 3-25 KW - Phosphinines AB - A review. This review deals with the chem. of phosphinines. As many reviews are available on the syntheses of these derivs., only the most versatile methods are presented, or the ones giving access to the phosphinines that were particularly studied. Then, recent results obtained in the coordination chem. of phosphinines are summarized with an emphasis on their analogy with CO ligands. Indeed, the 1st studies proved these ligands to be well adapted for the stabilization of electron rich metal centers. Shortly after, highly reduced complexes were obtained through the reaction of reduced 2,2'-biphosphinine dianions with transition metal fragments. Theor. calcns. were performed to establish the oxidn. state of the metal in these complexes. However, the various coordination studies have pointed out that phosphinines become sensitive toward nucleophiles once they are bound to (even slightly) oxidized metal centers. This sensitivity precluded their use in most catalytic processes, but the cases in which they could be used efficiently are presented in this review. Two ways to circumvent this drawback have been developed lately. The 1st method relies on the use of the high electrophilicity of the P atom of the phosphinine moiety. The ring is readily transformed into phosphacyclohexadienyl anions, which exhibit surprising coordination chem. and promising behavior in catalysis. Results in this domain are presented. The 2nd method is based on the involvement of the ring, as phosphadiene, into [4 + 2] Diels Alder type cycloaddns. leading to phosphabarrelene derivs. These ligands also show promising results in catalytic processes. Finally, phosphinines were used successfully to stabilize Au nanoparticles, which opens a whole new field of applications for these ligands. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Milyukov, V.A. AU - Budnikova, Y.H. AU - Sinyashin, O.G. PY - 2005 TI - Organic Chemistry of Elemental Phosphorus SP - 781-805 KW - Phosphorus, elemental AB - A review. The principal achievements and the modern trends in the development of the chem. of elemental P are analyzed, described systematically and generalized. The possibilities and advantages of the prepn. of organophosphorus compds. directly from white P are demonstrated. Attention is focused on the activation and transformation of elemental P in the coordination sphere of transition metal complexes. The mechanisms of the reactions of white P with nucleophilic and electrophilic reagents are discussed. Electrochem. approaches to the synthesis of org. P derivs. based on white P are considered. The bibliog. includes 251 refs. JO - Russian Chemical Reviews VL - 74 ER - TY - JOUR AU - Mindiola, D.J. PY - 2006 TI - Oxidatively Induced Abstraction Reactions. A Synthetic Approach to Low-Coordinate and Reactive Early Transition Metal Complexes Containing Metal-Ligand Multiple Bonds SP - 813-21 KW - Alkylidene-Ti complex Phosphinidene-Ti complex AB - A review. A library of low-coordinate Ti and V complexes contg. terminal metal-ligand multiply bonded functionalities such as alkylidenes, alkylidynes, and imides were prepd. by 1-electron oxidatively induced .a.-H abstraction reactions. In the case of the alkylidene motif, the nucleophilic nature of the M-C multiple bond permits subsequent reactions such as .a.-H migration to generate other rare functionalities such as phosphinidene-alkyl and imide-alkyls. Identifying and fine-tuning of the supporting ancillary ligand on the metal gave kinetically stable Ti alkylidene and phosphinidene systems. The former is a key functionality to generate transient Ti alkylidynes, which readily engage in intermol. C-H activation reactions of arenes and alkanes, and the ring-opening metathesis of arom. substrates such as pyridines. In this Account, the authors describe several synthetic strategies to achieve reactive functionalities, functionalities that were previously portrayed as incompatible or too kinetically reactive with 3d early transition metals. JO - Accounts of Chemical Research VL - 39 ER - TY - JOUR AU - Mo, Y. PY - 2006 TI - Intramolecular Electron Transfer: Computational Study Based on the Orbital Deletion Procedure (ODP) SP - 779-90 KW - Electron transfer, intramolecular AB - A review. The elucidation of the mol. structure-property relations requires the rational estn. of steric and electronic effects which govern the mol. structures. To this end, the authors proposed a simple ab initio method called orbital deletion procedure (ODP) which can quant. probe the intramol. electron transfer effect in carbocations and boranes. This method can not only explore the impact of electron transfer on mol. structures and stabilities, but probe the electron transfer efficiency in some electron donor-bridge-electron acceptor (DBA) complexes. In this Review, the authors will demonstrate the significance of the intramol. steric effect by comparing the planar and staggered structures of tetrahydrodiboron (B2H4) and halogenated diboranes (B2X4, X = F, Cl, Br). By deactivating the electronic effect, in these systems the staggered structures are consistently stabilized by 4-11 kcal/mol compared with the planar structures, which supports very recent conclusion that the ethane rotation barrier is dominated by the steric hindrance rather than the hyperconjugative interactions. The authors further analyzed a few carbocations and demonstrated how conjugation or hyperconjugation can remarkably influence the mol. structures and properties. Based on the ODP method, the authors proposed a two-state model which can straightforwardly compute the electron-transfer matrix element which is directly related to the electron transfer efficiency and kinetics in H2C-bridge-CH2+ DBA complexes. The authors employed this ODP-based two-state model to study the electron transport across strain-free linear alkyl chains (CH2)n (n = 1-8) and linear .p.-conjugated bridges (CH = CH)n (n = 1-5). JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Moberg, C. PY - 2006 TI - Can C3-Symmetric Receptors Differentiate Enantiomers SP - 4721-3 KW - Chiral recognition, C3-symmetric receptors Catalyst, C3-symmetric AB - A review. Symmetry and chiral recognition: In contrast to previous arguments, recent reports have demonstrated that C3-sym. receptors can bind chiral substrates with high enantioselectivity (H = host, G = (S) or (R)-configured guest; colored spheres represent different-sized substituents). JO - Angewandte Chemie, International Edition VL - 45 ER - TY - JOUR AU - Morton, D. AU - Stockman, R.A. PY - 2006 TI - Chiral Non-Racemic Sulfinimines: Versatile Reagents for Asymmetric Synthesis SP - 8869-905 KW - Sulfinimines, chiral JO - Tetrahedron VL - 62 ER - TY - BOOK AU - Mueller, T.J. AU - Ed PY - 2006 BT - Metal Catalyzed Cascade Reactions. [In: Top. Organomet. Chem., 2006; 19] CY - Berlin, Germany PB - Springer SP - 339 KW - Cascade reactions, metal catalyst, book ER - TY - JOUR AU - Muller, P. AU - Allenbach, Y.F. AU - Chappellet, S. AU - Ghanem, A. PY - 2006 TI - Asymmetric Cyclopropanations and Cycloadditions of Dioxocarbenes SP - 1689-96 KW - Dioxocarbenes, cyclopropanation Dioxocarbenes, cycloaddition Olefins, cyclopropanation AB - A review summerizes the methods recently developed for enantioselective transfer of carbenes starting from precursors carrying two carbonyl groups. A one-pot procedure for olefin cyclopropanation with CH-acidic precursors via intermediate phenyliodonium ylides has been developed. The [Rh2{(S)-nttl}4] catalyst was optimized to produce up to 98% ee in olefin cyclopropanations with di-Me malonate or Meldrum's acid. Highly selective Rh(II)-catalyzed olefin cyclopropanations could be obsd. upon replacement of Me diazoacetoacetate by Me (silyloxyvinyl)diazoacetate. Enantioselective dipolar cycloaddns. of diazopyruvate to polar olefins have been realized with Ru(II)-pybox catalysts. JO - Synthesis ER - TY - JOUR AU - Mulzer, J. AU - Castagnolo, D. AU - Felzmann, W. AU - Marchart, S. AU - Pilger, C. AU - Enev, V.S. PY - 2006 TI - Toward the Synthesis of the Antibiotic Branimycin: Novel Approaches to Highly Substituted Cis-Decalin Systems SP - 5992-6001 KW - Branimycin, synthesis Cis-decalin systems, preparation AB - A review. A variety of highly functionalized cis-decalin systems have been prepd. by means of the stereoselective transannular Diels-Alder (TADA) reaction of a (Z,E,Z,Z)-tetraene macrolide, and by means of JO - Chemistry--A European Journal VL - 12 ER - TY - JOUR AU - Murahashi, T. AU - Fujimoto, M. AU - Oka, M.-a. AU - Hashimoto, Y. AU - Uemura, T. AU - Tatsumi, Y. AU - Nakao, Y. AU - Ikeda, A. AU - Sakaki, S. AU - Kurosawa, H. PY - 2006 TI - Discrete Sandwich Compounds of Monolayer Palladium Sheets SP - 1104-7 KW - Sandwich complexes, Pd AB - Despite the abundance of sandwich complexes, in which two cyclic arom. hydrocarbon ligands flank a metal center, this motif was not extended to sheets of multiple metal atoms. The authors prepd. and isolated two such compds. In the 1st, three Pd centers form a planar triangular array, capped by chlorides, between two cycloheptatrienyl ligands. In the 2nd, a pentapalladium sheet adopts an edge-sharing triangle-trapezoid skeleton between two naphthacene rings. The compds. were characterized by x-ray crystallog. and NMR spectroscopy. The nature of the bonding in the clusters was analyzed by quantum mech. calcns. JO - Science VL - 313(5790) ER - TY - JOUR AU - Nair, V. AU - Menon, R.S. AU - Sreekanth, A.R. AU - Abhilash, N. AU - Biju, A.T. PY - 2006 TI - Engaging Zwitterions in Carbon-Carbon and Carbon-Nitrogen Bond-Forming Reactions: A Promising Synthetic Strategy SP - 520-30 KW - Zwitterions, C-C bond formation AB - A review. An Account of carbon-carbon and carbon-nitrogen bond-forming reactions mediated by zwitterions generated by the addn. of org. nucleophiles to activated unsatd. systems highlighting their synthetic potential is presented. JO - Accounts of Chemical Research VL - 39 ER - TY - JOUR AU - Nair, V. AU - Thomas, S. AU - Mathew, S.C. AU - Abhilash, K.G. PY - 2006 TI - Recent Advances in the Chemistry of Triaryl- and Triheteroarylmethanes SP - 6731-47 KW - Triheteroarylmethanes Triarylheteroarylmethanes JO - Tetrahedron VL - 62 ER - TY - JOUR AU - Nieto-Oberhuber, C. AU - Lopez, S. AU - Jimenez-Nunez, E. AU - Echavarren, A.M. PY - 2006 TI - The Mechanistic Puzzle of Transition-Metal-Catalyzed Skeletal Rearrangements of Enynes SP - 5916-23 KW - Enynes, cyclization Cyclobutenes, synthesis AB - A review. Three pathways actually compete in metal-catalyzed cyclizations of enynes in which the metal selectively activates the alkyne: an endocyclic process and two exo-cyclizations, one proceeding by anti attack of the alkene and a second one resulting in a syn addn. Although cyclobutenes may be formed in transition-metal-catalyzed cyclization of some enynes, particularly, 1,7-enynes, these compds. are not necessarily the intermediates in the skeletal rearrangement. Cyclobutenes are formed by ring expansion of syn-cyclopropyl metal-carbenes formed in the syn pathway. JO - Chemistry--A European Journal VL - 12 ER - TY - BOOK AU - Ning, Y.C. PY - 2005 BT - Structural Identification of Organic Compounds with Spectroscopic Techniques CY - Weinheim, Germany PB - Wiley-VCH SP - 340 KW - Spectroscopy, book ER - TY - JOUR AU - Nishibayashi, Y. AU - Uemura, S. PY - 2006 TI - Ruthenium-Catalyzed Novel Carbon-Carbon Bond Forming Reactions via Ruthenium-Allenylidene Complexes SP - 135-50 KW - Ruthenium, allenylidene complexes AB - A review. The authors' recent studies on novel C-C bond forming reactions using propargylic alcs. catalyzed only by thiolate-bridged diruthenium complexes are reviewed from the viewpoint of org. synthesis. The reactions are substitutions of hydroxyl group of the alcs. with a variety of C-centered nucleophiles such as simple ketones, cyclic 1,3-dicarbonyl compds., arom. and heteroarom. compds., phenols, naphthols, and alkenes. The asym. version of propargylic alkylation with acetone is also described. All of the reactions are considered to proceed via Ru-allenylidene complexes as key intermediates. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Odinets, I.L. AU - Vinogradova, N.M. AU - Matveeva, E.V. AU - Mastryukova, T.A. PY - 2005 TI - Synthesis and Coordination Chemistry of Cyano-Substituted Phosphines SP - 1899-934 KW - Phosphines, cyano-substituted AB - A review. Synthetic approaches to both linear and cyclic cyano-substituted phosphines (P?CN-phosphines) found an industrial application as catalyst precursors, pesticides, herbicides, flame retardants, precursors of aminophosphines etc., are reported. The main synthetic routes include redn. of P:O contg. precursors, alkylation of silylphosphines and metal phosphides by haloalkyl(aryl)carbonitriles, phosphorylation of the latter ones, decompn. of phosphonium salts and hydrophosphination of cyano-substituted olefins proceeding under noncatalytic conditions and using metal complex catalysis. Advantages and disadvantages of each approach are discussed. Phosphines bearing cyano function as an addnl. coordination site show diverse coordination behavior depending on the phosphine structure and nature of the metal. Four main types of complexes are obsd., those with P-monodentate coordination, with N-monodentate coordination and complexes where bidentate coordination mode of P and N atoms is realized either at the single metal atom or of bridged type between two different metal atoms. Thus coordination behavior of such P?CN-ligands relative to transition and nontransition metals, JO - Current Organic Chemistry VL - 9 ER - TY - BOOK AU - Orchin, M. AU - Macomber, R.S. AU - Pinhas, A.R. PY - 2005 BT - The Vocabulary and Concepts of Organic Chemistry, 2nd Edition CY - Chichester, U.K. PB - John Wiley & Sons SP - 800 KW - Vocabulary, book ER - TY - JOUR AU - Orito, Y. AU - Nakajima, M. PY - 2006 TI - Lewis Base Catalyzed Asymmetric Reactions Involving Hypervalent Silicate Intermediates SP - 1391-401 KW - Silicates, hypervalent Lewis bases, asymmetric reactions AB - A review. The development of catalytic enantioselective reactions is a challenging area in synthetic org. chem. In the last decade, numerous chiral metal complexes, which act as Lewis acids, have been very successful. However, Lewis base catalyzed asym. reactions are also attracting attention. Recent developments in silicon-based chem. have led to new asym. reactions, which involve so-called hypervalent silicates as intermediates, wherein new types of organocatalysts are often utilized as promoters. This review presents the progress in silicate-mediated asym. reactions catalyzed by chiral Lewis bases, particularly those based on various types of silicon compds. JO - Synthesis ER - TY - BOOK AU - Orru, R.V.A. AU - Ed PY - 2006 BT - Special Issue: Multicomponent Reactions. [In: QSAR Comb. Sci.; 2006, 25(5-6)] CY - Weinheim, Germany PB - Wiley-VCH Verlag KW - Multicomponent reactions, book ER - TY - JOUR AU - Pace, A. AU - Buscemi, S. AU - Vivona, N. PY - 2005 TI - The Synthesis of Fluorinated Heteroaromatic Compounds. Part 1. Five-Membered Rings with More Than Two Heteroatoms SP - 447-506 KW - Heteroaromatics, fluorinated JO - Organic Preparations and Procedures International VL - 37 ER - TY - JOUR AU - Palko, M. AU - Kiss, L. AU - Fulop, F. PY - 2005 TI - Syntheses of Hydroxylated Cyclic .b.-Amino Acid Derivatives SP - 3063-83 KW - Amino acids, .b.-, hydroxylated, cyclic AB - A review. This review is intended to give a short summary of the developments in the field of natural and synthetic alicyclic and heterocyclic hydroxylated .b.-amino acids and to focus on the main strategies that have been reported for their synthesis. Given the medicinal and biol. significance of the hydroxylated .b.-amino acids, an increasing vol. of research is currently being directed toward regio-, stereo- and enantioselective access to this class of compds. JO - Current Medicinal Chemistry VL - 12 ER - TY - JOUR AU - Parkin, G. PY - 2006 TI - A Simple Description of the Bonding in Transition-Metal Borane Complexes SP - 4744-7 KW - Borane complexes, bonding AB - A review of nomenclature of the description of the bonding in transition-metal borane complexes. JO - Organometallics VL - 25 ER - TY - JOUR AU - Parkins, A.W. PY - 2006 TI - The Migration and Cleavage of Substituents from Donor Atoms in Coordination Compounds of the Transition Metals SP - 449-67 KW - Organometallic compounds, cleavage Organometallic compounds, migration AB - A review brings together reactions involving the cleavage of org. substituents from donor atoms in coordination and organometallic compds. In some cases the substituent is lost, in others it migrates to the metal. A few cases of migration from the metal to the donor atom are included. The information is scattered widely in the literature, and was compiled as a survey of groups of the periodic table. JO - Coordination Chemistry Reviews VL - 250 ER - TY - JOUR AU - Pellissier, H. PY - 2006 TI - Use of Chiral Sulfoxides in Asymmetric Synthesis SP - 5559-601 KW - Sulfoxides, chiral AB - A review examines the recent (since 2000) advances in the use of non-racemic sulfoxides as chiral auxiliaries in asym. synthesis, focusing on their application in the synthesis of biol. active products. The article is divided according to the different types of reactions used for generation of new stereogenic centers and includes redn. and cycloaddn. reactions, addn. reactions of sulfoxide-stabilized carbanions, conjugate addn. to .a.,.b.-unsatd. sulfoxides, and Pummerer reactions. Diastereoselective processes promoted by transition metals are also discussed. JO - Tetrahedron VL - 62 ER - TY - JOUR AU - Pena, D. AU - Perez, D. AU - Guitian, E. PY - 2006 TI - Insertion of Arynes into .s. Bonds SP - 3579-81 KW - Arynes, insertion into .s.-bonds Arenes, ortho-disubstituted AB - A review. Following a quiet period, numerous reports have recently appeared regarding the insertion of arynes into .s. bonds as a result of milder, high-yielding methods for generating arynes and the introduction of palladium catalysis into aryne chem. The methodol. shows promise as a means of prepg. complex ortho-disubstituted arenes. JO - Angewandte Chemie, International Edition VL - 45 ER - TY - JOUR AU - Percece, V. AU - Ungar, G. AU - Peterca, M. PY - 2006 TI - Self-Assembly in Action SP - 55-6 KW - Self-assembly, supramolecules AB - A review. Growth of supramol. structure is in some respects analogous to a phase transition and thus can be described by familiar thermodn. models. JO - Science VL - 313(5783) ER - TY - JOUR AU - Pietrusiewicz, K.M. AU - Stankevic, M. PY - 2005 TI - Phosphinous Acid-Boranes SP - 1883-97 KW - Phosphinous acid-boranes AB - A review. Borane complexes of trivalent P compds. have attracted a continuously growing interest over the past four decades. Their remarkable air and configurational stability combined with a relative easiness of fully stereoretentive removal of the protecting borane moiety quickly made them reagents of choice for the elaboration of phosphine structures esp. suited for the prepn. of chiral phosphine ligands. Borane complexes of primary, secondary, and tertiary phosphines, phosphinites, phosphonites, and phosphites can be readily obtained by directly reacting the corresponding trivalent P compd. with a convenient borane donor like BH3-THF, BH3-SMe2 etc. Similarly, straightforward access to borane complexes of free trivalent P acids has for a long time been stymied by the fact that these acids exist predominantly as their tetracoordinate tautomers, which are unable to take part in the direct complexation with BH3. As a consequence, the known examples of borane complexes of trivalent P acids were very few in no., and all were obtained by the indirect routes. With the possible exception of borane-modified nucleotides, the properties and chem. of borane complexes of trivalent P acids have thus remained practically unexplored. This was esp. true for phosphinous acids-boranes, for which, until very recently, only two fully identified examples could be found in the literature. Recent developments of general methods for synthesis of such compds. have made them now readily available in a great structural variety and in the non-racemic forms as well, and allowed for a systematic study of their chem. and synthetic utility. The purpose of this account is to describe these new results and to demonstrate the utility of phosphinous acid-boranes as an emerging class of useful synthetic intermediates. Details of the studies of the reactions of secondary phosphine oxides with borane reagents that were rudimentary to the development of general synthetic routes to phosphinous acid-boranes will also be presented. JO - Current Organic Chemistry VL - 9 ER - TY - CHAP AU - Pilli, R., A. AU - et al. PY - 2006 BT - Alkaloids: Chemistry and Biology, Volume 62. ED - Cordell, G.A. AU - Ed CT - The Stemona Alkaloids CY - San Diego, CA PB - Elsevier SP - 266 KW - Alkaloids, book ER - TY - JOUR AU - Pinho e Melo, T.M.V.D. PY - 2006 TI - Conjugated Azomethine Ylides SP - 2873-88 KW - Azomethine ylides, cycloaddition Heterocycles, N-, synthesis AB - A review. The 1,3-dipolar cycloaddn. of azomethine ylides is an efficient and versatile tool for the construction of five-membered nitrogen-heterocycles. When the azomethine ylide is conjugated with a double bond or a 1,3-diene moiety, other reactivity pathways are also available, namely 1,5-electrocyclization or 1,7-electrocyclization. The present review is focused on the generation and reactivity of this type of dipoles, which offer general strategies for the formation of five- and seven-membered nitrogen-heterocyclic compds. JO - European Journal of Organic Chemistry ER - TY - JOUR AU - Prashar, S. AU - Antinolo, A. AU - Otero, A. PY - 2006 TI - Insights into Group 4 and 5 Ansa-bis(cyclopentadienyl) Complexes with a Single-Atom Bridge SP - 133-54 KW - Ansa-bis(cyclopentadienyl) complexes AB - A review. This review describes the different synthetic strategies employed in the prepn. of Group 4 and 5 ansa-bis(cyclopentadienyl) complexes contg. a Group 14 single-atom bridge. The general preparative routes can be summarized in: (i) metathesis reactions using alkali-metal ansa-ligand precursors; (ii) transmetalation with Sn substituted cyclopentadiene compds.; (iii) reaction of the metal amide derivs. with ansa-bis(cyclopentadiene) compds. Excluding fused ring systems, such as indenyl or fluorenyl, it is still nevertheless evident the wide variety of complexes that are reported. Substituents can be varied in nature, position and/or no. at the C5 ring and/or at the single-atom ansa-bridge. Functional groups also were introduced into the ansa-ligand framework and their reactivity in, for example, hydroboration, hydrosilylation or stereoselective .a.-olefin polymn. is described in this review. JO - Coordination Chemistry Reviews VL - 250 ER - TY - JOUR AU - Pratviel, G. AU - Meunier, B. PY - 2006 TI - Guanine Oxidation: One- and Two-Electron Reactions SP - 6018-30 KW - Guanine oxidation AB - A review discusses the oxidn. of guanine in DNA by various oxidizing agents, the structures of the products, the mechanisms of oxidn. by one- and two-electron oxidants, and the dependence of the chemoselectivity of oxidn. on reaction conditions. JO - Chemistry--A European Journal VL - 12 ER - TY - JOUR AU - Quiclet-Sire, B. AU - Zard, S.Z. PY - 2006 TI - Powerful Carbon-Carbon Bond Forming Reactions Based on a Novel Radical Exchange Process SP - 6002-16 KW - Olefins, intermolecular radical addition Xanthates, radical additions Aromatics, radical additions AB - A review. Xanthates and related derivs. have proved to be extremely useful for both inter- and intramol. radical addns. The broad applicability of the intermol. addn. to unactivated olefins opens tremendous opportunities for synthesis, since various functional groups can be brought together under mild conditions and complex structures can be rapidly assembled. The presence of the xanthate in the product is also a powerful asset for further modifications, by both radical and non-radical pathways. Of special importance is the access to highly substituted arom. and heteroarom. derivs. and the synthesis of block polymers through a controlled radical polymn. mediated by various thiocarbonylthio group contg. agents (RAFT and MADIX processes). JO - Chemistry--A European Journal VL - 12 ER - TY - JOUR AU - Quin, L.D. PY - 2006 TI - The Continuing Development of the Chemistry of Phospholes SP - 43-78 KW - Phospholes AB - A review. The last five years have seen many advances in the chem. of phospholes. Motivating much of the work was the potential for discovering valuable applications of phospholes, esp. as ligands in metal coordination compds. designed for use as homogeneous catalysts, and in the field of electrooptical substances. This review covers the research in the synthesis, properties and applications of phospholes that was published since the last comprehensive review by the author in 1999. While prepd. for the specialist, the review is designed to introduce some of the aspects of phosphole chem. to the general reader. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Radius, U. AU - Breher, F. PY - 2006 TI - To Boldly Pass the Metal-Metal Quadruple Bond SP - 3006-10 KW - Metal-metal quintuple bond AB - A review of the metal-metal quintuple bond. Minimizing the no. of sterically demanding ligands increases the no. of valence orbitals available to form metal-metal bonds. Following this concept, P. P. Power et al. have recently synthesized and structurally characterized a dinuclear Cr-Cr-bonded complex with one ligand per metal atom featuring a metal-metal quintuple bond. Driving this concept to an extreme, even larger bond orders than five should be feasible. JO - Angewandte Chemie, International Edition VL - 45 ER - TY - JOUR AU - Ragaini, F. AU - Cenini, S. AU - Gallo, E. AU - Caselli, A. AU - Fantauzzi, S. PY - 2006 TI - Fine Chemicals by Reductive Carbonylation of Nitroarenes, Catalyzed by Transition Metal Complexes SP - 1479-510 KW - Nitroarenes, reductive carbonylation Indoles, synthesis Quinolinones, synthesis Pyrroles, synthesis AB - A review. The application of reductive carbonylation of nitroarenes to the synthesis of fine chems. is described. The review focuses on the results reported from 1996 onwards and is mainly divided in two parts, resp. describing the intra-mol. cyclization reactions of nitroarenes bearing in the ortho position a suitable functional group and the inter-mol. reactions of nitroarenes with external olefins and alkynes. Benzo-fused heterocycles such as indoles and quinolinones were obtained by the 1st group of reactions, whereas allylic amines, oxazines, pyrroles and indoles are the products of inter-mol. reactions. Mechanistic studies are also discussed in a sep. section. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Rakhmankulov, D.L. AU - Shavshukova, S.Y. AU - Latypova, F.N. PY - 2005 TI - Synthesis and Transformations of Heterocyclic Compounds Under the Influence of Microwave Radiation SP - 951-61 KW - Heterocycles, microwaves AB - A review. Published data (38 ref.) on the synthesis and transformations of heterocyclic compds. with microwave treatment were analyzed and classified according to the types of products formed. The chapters included oxygen heterocycles, nitrogen and sulfur heterocycles, and rings contg. two different heteroatoms. The results of analogous reactions conducted with normal heating were given for comparison. JO - Chemistry of Heterocyclic Compounds VL - 41(8) ER - TY - JOUR AU - Ramachandran, P.V. AU - Burghardt, T.E. PY - 2006 TI - Recent Developments in the Chiral Synthesis of Homoallylic Amines via Organoboranes SP - 1397-406 KW - Amines, homoallylic, via organoboranes AB - A review. Among the plethora of protocols for the prepn. of chiral homoallylic amines, the use of boron-based reagents remains relatively undeveloped. However, the recent advances in the use of .a.-pinene-based versatile reagents for the synthesis of such amines confirmed that very high enantioselectivity and outstanding diastereoselectivity can be readily achieved. Addn. of the "allyl" boron reagents to various N-substituted imines provided the desired amine products in high yields and high to very high ee. The discovery that an addn. of 1.0 equiv of methanol or water to the "allyl" boration reaction with N-masked imines is crit. allowed for higher yields and noticeably improved ee. The use of N-aluminoimines, which are not only easy to prep. by a partial redn. of nitriles, but are also relatively stable for both enolizable and non-enolizable substrates, considerably expanded the scope of the reactions. In this review, the developments in the syntheses of chiral homoallylic amines using organoboranes, with the particular accent on the reagent-controlled reactions, are summarized. Addnl., the novel methodol. for the crotyl- and alkoxyallylboration of imines using trialkylboron "ate" complexes is described. JO - Pure and Applied Chemistry VL - 78 ER - TY - BOOK AU - Rappoport, Z. AU - Ed PY - 2006 BT - The Chemistry of Peroxides, Volume 2; Part 2 CY - Chichester, U.K. PB - John Wiley & Sons SP - 723 KW - Peroxides, book ER - TY - BOOK AU - Rappoport, Z. AU - Ed PY - 2006 BT - The Chemistry of Peroxides, Volume 2; Part 1 CY - Chichester, U.K. PB - John Wiley & Sons SP - 774 KW - Peroxides, book ER - TY - JOUR AU - Reeder, M.R. AU - Anderson, R.M. PY - 2006 TI - .a.-Aminoalkyl-.a.'-Halomethyl Ketones: Preparation and Application to Pharmaceutically Interesting Compounds SP - 2828-42 KW - Aminoalkylhalomethyl ketones Saquinavir synthesis, with aminoalkylhalomethyl ketones AB - A review. The prepn. of .a.-aminoalkyl-.a.'-(halomethyl) ketone derivs. was reviewed. The application of these compds. toward the synthesis of saquinavir (invirase), palinavir, nelfinavir (viracept), amprenavir (agenerase) was discussed. JO - Chemical Reviews VL - 106(7) ER - TY - JOUR AU - Reiser, O. PY - 2006 TI - Palladium-Catalyzed Coupling Reactions for the Stereoselective Synthesis of Tri- and Tetrasubstituted Alkenes SP - 2838-40 KW - Alkenes, tetrasubstituted AB - A review. Efficient strategies relying on palladium-catalyzed cross-coupling reactions are now available for the assembly of trisubstituted and tetrasubstituted alkenes with excellent stereocontrol. JO - Angewandte Chemie, International Edition VL - 45 ER - TY - JOUR AU - Renaud, J.-L. AU - Demerseman, B. AU - Mbaye, M.D. AU - Bruneau, C. PY - 2006 TI - .h.3-Allylruthenium Complexes and Ruthenium-Catalysed Nucleophilic Substitution of Allylic Substrates SP - 115-33 KW - Ruthenium, allyl complexes AB - A review. Recent developments in the chem. of .h.3-allylruthenium complexes (synthesis and reactivity) are described. Among different possible prepns., their straightforward formation via oxidative addn. of allylic substrates occurs either at Ru(0) or Ru(II) centers. Subsequent reaction with an electrophile or a nucleophile is the basis of their ambiphilic involvement in catalysis. In this review, the authors focus on catalytic substitution of allylic substrates by C, N, O and S-nucleophiles, and show that selected ligands make possible stereospecific, as well as regio- and enantioselective substitutions. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Ribiere, P. AU - Declerck, V. AU - Martinez, J. AU - Lamaty, F. PY - 2006 TI - 2-(Trimethylsilyl)ethanesulfonyl (or SES) Group in Amine Protection and Activation SP - 2249-2269 KW - Trimethylsilyl)ethanesulfonyl group Amines, protection Amines, activation JO - Chemical Reviews VL - 106(6) ER - TY - JOUR AU - Richardson, R.D. AU - Wirth, T. PY - 2006 TI - Hypervalent Iodine Goes Catalytic SP - 4402-4 KW - Oxidation, with hypervalent iodine Hydroxylation, with hypervalent iodine Acyloxylation, with hypervalent iodine AB - A review discusses the recent development of oxidn. and hydroxylation (acyloxylation) reactions and oxidative cyclizations using catalytic amts. of hypervalent iodine compds. generated from aryl iodides in situ with a stoichiometric oxidant. JO - Angewandte Chemie, International Edition VL - 45 ER - TY - JOUR AU - Richmond, M.G. PY - 2005 TI - Annual Survey of Organometallic Metal Cluster Chemistry for the Year 2003 SP - 2763-86 KW - Organometallic metal clusters AB - A review. The synthetic, mechanistic, and structural chem. of organometallic metal cluster compds. is reviewed for the year 2003. JO - Coordination Chemistry Reviews VL - 249 ER - TY - JOUR AU - Rinderhagen, H. AU - Waske, P.A. AU - Mattay, J. PY - 2006 TI - Facile Ring Opening of Siloxy Cyclopropanes by Photoinduced Electron Transfer. A New Way to .b.-Keto Radicals SP - 6589-93 KW - Cyclopropanes, siloxy, ring opening AB - A review of primarily the authors' work on the title subject. Siloxy cyclopropanes undergo ring opening and fragmentation of formal silyl cations under formation of .b.-keto radicals. These reactive intermediates can be used in inter- and intramol. addn. reactions leading to complex ring systems if more than one unsatd. side chain is present in the starting material. Beside some synthetic examples mainly the mechanism is discussed focusing on the structure of the primarily formed radical cations, the regioselectivity of cyclopropane cleavage (endo vs. exo ring opening), leaving of the silyl group, and termination by H-transfer. JO - Tetrahedron VL - 62 ER - TY - JOUR AU - Roesky, H.W. AU - Singh, S. AU - Yusuff, K.K.M. AU - Maguire, J.A. AU - Hosmane, N.S. PY - 2006 TI - Organometallic Hydroxides of Transition Elements SP - 3813-43 KW - Transition metal hydroxides JO - Chemical Reviews VL - 106(9) ER - TY - JOUR AU - Romanenko, V.D. AU - Kukhar, V.P. PY - 2006 TI - Fluorinated Phosphonates: Synthesis and Biomedical Application SP - 3868-935 KW - Phosphonates, fluorinated AB - A review. The synthesis, fundamental chem. properties, and biomedical uses of the phosphonic acid derivs. that bear at least one F substituent on the organyl moiety are the subject of this review, which is organized as follows. The 1st part is a survey of synthetic methods used for the prepn. of fluorinated phosphonates. The 2nd part consists of a presentation of the different types of fluorophosphonates having significant biol. importance. The 3rd part describes the use of fluorinated phosphonates in biomedical studies (e.g. enzyme inhibitors, catalytic antibodies, antiviral agents, antitumor agents, anti-platelet-aggregation agents). Discussion of basic aspects of phosphonate and organofluorine chem. is reduced to min. to avoid redundancy to the long series of papers already published in journals and books. Also no particular attention will be paid to subjects that have recently been reviewed. In such cases, only the most important trends are briefly summarized. Literature coverage for the review extends up to Apr. 2006. JO - Chemical Reviews VL - 106(9) ER - TY - JOUR AU - Rossi, R.A. AU - Martin, S.E. PY - 2006 TI - Syntheses and Applications of Organostannanes Bonded to Elements of Groups XIV, XV, and XVI SP - 575-601 KW - Organostannanes AB - A review. This review highlights the synthesis and applications of bimetallic and heteroatoms stannanes R3Sn-M (M = Si, Sn, Ge, P, As, Sb, S, Se, and Te) derived from elements of the groups XIV, XV, and XVI. Different types of reactions are described: transition metal-catalyzed addn. of hetero-bimetallic (R3Sn-SiR13 or R3Sn-SnR13) compds. to multiple bonds, transition metal-catalyzed cross-coupling reactions of the organostannanes with a variety of electrophiles and other general reactions, such as substitution or complex formation. JO - Coordination Chemistry Reviews VL - 250 ER - TY - JOUR AU - Rousseau, G. AU - Blanco, L. PY - 2006 TI - Heterocyclic Compounds with a Silicon Atom and Another Non-Adjacent Different Heteroatom SP - 7951-93 KW - Heterocycles, Si JO - Tetrahedron VL - 62 ER - TY - JOUR AU - Saraber, F.C.E. AU - de Groot, A. PY - 2006 TI - Ring C Closure as Key Step in the Synthesis of Steroids SP - 5363-83 KW - Steroids, synthesis, ring closure AB - A review. Syntheses of steroids can be achieved by partial synthesis, modification of readily available steroidal compds. or total synthesis. The latter is the most applied method and has been widely studied during the 20th century, the first total synthesis of a steroid being reported in 1939 by Bachmann, Cole and Wilds. Steroid total synthesis remains to this day a topic of interest for synthetic org. chemists and the pharmaceutical industry, even though many elegant syntheses have been developed. The efficiency of routes towards adequately functionalized steroid skeletons, which preferably also should be chiral, short and versatile, can, however, be improved, and this explains why research in this area is still ongoing. This review focused on approaches in which the formation of ring C is the crucial step. The review was further subdivided according to the reaction types used for the construction of ring C, thus giving an insight into closing methods used in this corner of steroid total synthesis. JO - Tetrahedron VL - 62 ER - TY - JOUR AU - Sasamori, T. AU - Tokitoh, N. PY - 2006 TI - Sila- and Germacyclopropabenzenes SP - 3522-32 KW - Germacyclopropabenzenes Silacyclopropabenzenes AB - This review article describes the initial work on the sila- and germacyclopropabenzenes, the heavier congeners of cyclopropabenzenes that have a silicon or germanium atom instead of a carbon atom as the bridging atom of its cyclopropabenzene skeleton. The key factor in their successful prepn. is the development of a synthetic method that is effective under mild conditions, i.e., the reaction of a dilithio compd. (Tbt(Dip)MLi2 (M = Si, Ge)) that has effective steric protective groups, 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl (denoted as Tbt) and 2,6-diisopropylphenyl (denoted as Dip), with 1,2-dibromobenzene at -78°. These were successfully applied to the synthesis of not only sila- and germacyclopropabenzenes but also stable bis(sila- and germacyclopropa)benzenes with two sila- and germacyclopropene rings fused to one benzene ring. These compds. are the heavier congeners of the unknown bis(cyclopropa)benzene deriv. JO - Organometallics VL - 25 ER - TY - JOUR AU - Scarso, A. AU - Rebek, J., Jr. PY - 2006 TI - Chiral Spaces in Supramolecular Assemblies SP - 1-46 KW - Supramolecules, chiral spaces AB - A review which is aimed at illustrating to the reader the state of the art on the construction of artificial chiral supramol. assemblies held together by weak intermol. noncovalent forces in soln. except metal-ligand coordination. Chiral supramols. are self-assembled finite aggregates characterized by the presence of chiral residues or by asym. arrangement of components. These assemblies proved to be powerful tools to explore chirality and its effects in host-guest interactions and represents important steps toward a superior control in asym. noncovalent synthesis, which is still a peculiar prerogative of natural systems. The introduction serves as a quick overview of weak (noncovalent) interactions refreshing concepts like cooperativity and multivalency that are crucial to mol. assembly, as well as providing selected examples of supramol. chiral systems found in nature. Four main strategies were so far employed for the prepn. of chiral supramol. assemblies: these are discussed on the bases of the nature of the monomeric components employed. Intrinsically chiral scaffolds were used both in the enantiopure or racemic mixt. form to assemble into chiral aggregates. A 2nd approach instead makes use of achiral building blocks to give racemic chiral supramols., and a step further consists of the enrichment of these species in one enantiomeric form exploiting the chiral memory effect. The last approach is based on encapsulation of chiral guests, which allows reciprocal sensing of chiral species confined in close proximity within an achiral host. JO - Topics in Current Chemistry VL - 265 ER - TY - JOUR AU - Schmidt, B. AU - Hermanns, J. PY - 2006 TI - "Ring Closing Metathesis of Substrates Containing More Than Two Carbon-Carbon Double Bonds: Rapid Access to Functionalized Heterocycles" SP - 1363-96 KW - Dienes, ring closing metathesis AB - A review. In most cases where ring closing metathesis is applied to the synthesis of heterocycles, .a.,.w.-dienes were used as precursors. If substrates contg. more than two double bonds are subjected to a metathesis reaction, carba- or heterocycles bearing addnl. exocyclic alkene functionality result, or multiple ring closing processes occur. This offers interesting and potentially very useful synthetic perspectives. However, selectivity problems need to be addressed as the cyclization of substrates with more than two double bonds available for olefin metathesis may result in constitutional isomers or stereoisomers. This review highlights problems and opportunities evolving from ring closing metathesis of tri-, tetra-, and polyenes as a strategy for the selective synthesis of functionalized heterocycles. The chapter on RCM of trienes is subdivided according to the symmetry of the metathesis precursor. The following two chapters deal with the double or multiple RCM of tetra- or polyenes. These processes are further classified according to the preferred cyclization mode. Finally, the application of cascade or domino metathesis reactions to the synthesis of heterocycles are discussed. These processes can be classified into those where exclusively carbon-carbon double bonds take part in the metathesis reaction, and those where one or more carbon-carbon triple bonds are involved. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Schnurch, M. AU - Flasik, R. AU - Khan, A.F. AU - Spina, M. AU - Mihovilovic, M.D. AU - Stanetty, P. PY - 2006 TI - Cross-Coupling Reactions on Azoles with Two and More Heteroatoms SP - 3283-307 KW - Azoles, cross-coupling AB - A review (178 refs.). Recent progress in the field of transition-metal-catalyzed cross-coupling reactions on various azole systems was summarized. Most important C-C- and C-X-bond formation methodologies (Negishi, Suzuki-Miyaura, Stille, Kumada-Corriu-Tamao, Hiyama, Sonogashira, Heck, C-H activation) were reviewed and discussed for the imidazole, oxazole, thiazole, pyrazole, isoxazole, and isothiazole system, as well as for azoles with more than two heteroatoms. This review covered the literature that appeared in the past ten years up to the end of 2005 with corresponding azoles used either as metal organyl or halide (including triflates and some other less frequently applied leaving groups). Literature describing azole structures only as ligands was not included. JO - European Journal of Organic Chemistry ER - TY - JOUR AU - Schramm, M.P. AU - Rebek, J., Jr. PY - 2006 TI - Moving Targets: Recognition of Alkyl Groups SP - 5924-33 KW - Alkyl chains, helixes AB - A review. Alkyl chains can adopt seemingly unusual conformations, such as helixes, when bound to natural and synthetic hydrophobic receptors. This plasticity allows the alkanes to assume shapes that are congruent to the receptor's space and fill that space properly. We describe here the use of cavitands and capsules as tools that expose the forces involved in the mol. recognition of hydrocarbons. Studies using NMR spectroscopy reveal how attractive interactions and solvophobic forces are maximized in soln. through unprecedented contortions of alkanes and hint at a new generation of nanoscale mech. devices. JO - Chemistry--A European Journal VL - 12 ER - TY - JOUR AU - Schultz, M.J. AU - Sigman, M.S. PY - 2006 TI - Recent Advances in Homogeneous Transition Metal-Catalyzed Aerobic Alcohol Oxidations SP - 8227-41 KW - Alcohol oxidation, Co,Cu,Pd AB - A review dealing with the homogeneous transition metal-catalyzed aerobic alc. oxidns. using catalysts contg. cobalt (e.g., cobalt acetate), copper (e.g., CuCl), palladium (e.g., palladium acetate), etc. JO - Tetrahedron VL - 62 ER - TY - JOUR AU - Scott, P.J.H. AU - Steel, P.G. PY - 2006 TI - Diversity Linker Units for Solid-Phase Organic Synthesis SP - 2251-68 KW - Solid-phase synthesis, linkers AB - A review. In recent years an ever-increasing no. of traditional soln.-phase reactions were adapted for solid-phase org. synthesis (SPOS) because of the ease of application of solid-phase techniques to combinatorial chem. and high-throughput screening. To accommodate the growing no. of reactions being attempted on solid supports, new linker units continue to be reported in the literature. Linker units are typically grouped according to the functionality left at the cleavage site in the target mol., and are normally classified as traditional (polar functionality remains following cleavage) or traceless (hydrogen residue left after cleavage) linkers. As the field continues to expand, however, more advanced linker units were reported, which use the cleavage step in SPOS to incorporate addnl. diversity into target libraries. These linker units were termed diversity or multifunctional linker units, and in this microreview the authors introduce this aspect of the field, giving representative examples indicating key stages of development including the linker units recently designed in lab. JO - European Journal of Organic Chemistry ER - TY - JOUR AU - Shvekhgeimer, M.G.A. PY - 2005 TI - Five-, Six-, and Seven-Membered Lactim Ethers. Methods of Synthesis and Chemical Properties SP - 551-91 KW - Lactim ethers AB - A review. Data on methods for the prodn. of 5-7-membered lactim ethers and their chem. transformations published after 1970 are reviewed. JO - Chemistry of Heterocyclic Compounds VL - 41(5) ER - TY - BOOK AU - Simonneaux, G. AU - Ed PY - 2006 BT - Bioorganometallic Chemistry. [In: Top. Organomet. Chem.; 2006, 17] CY - Berlin, Germany PB - Springer SP - 222 KW - Bioorganometallic chemistry, book ER - TY - JOUR AU - Sliwa, W. AU - Bachowska, B. PY - 2006 TI - Supramolecular Species Bearing Quaternary Azaaromatic Moieties SP - 1467-500 KW - Rotaxanes Catenanes Pretzelanes AB - A review. In the paper at first rotaxanes are presented; these species are divided into three classes, i.e. those contg. electron donor, electron acceptor and cyclodextrin mols. as rings. In following parts examples of catenanes, pretzelanes and mol. clips are described. JO - Heterocycles VL - 68 ER - TY - JOUR AU - Smirnova, N.G. AU - Zavarzin, I.V. AU - Krayushkin, M.M. PY - 2006 TI - Synthesis of Condensed Thiazoles SP - 144-65 KW - Thiazoles, condensed AB - A review. Data on the synthesis of the thiazole system condensed with heterocycles are classified. The principal directions in the practical application of these substances are briefly discussed. JO - Chemistry of Heterocyclic Compounds VL - 42(2) ER - TY - JOUR AU - Smith, K. AU - El-Hiti, G.A. PY - 2006 TI - Regioselective Electrophilic Aromatic Substitution Reactions over Reusable Zeolites SP - 1603-25 KW - Aromatics, substitution, zeolites Aryloxiranes, rearrangement, zeolites AB - A review. Zeolite catalysts can play an important role in the development of greener org. syntheses through their abilities to act as heterogeneous catalysts, support reagents, entrain byproducts, avoid aq. work-ups and enhance product selectivities via shape-selectivity. Zeolites under modest conditions can have advantages in para-regioselective nitration, alkylation, acylation, methanesulfonylation and halogenation of arom. compds. They can also assist in the electrophilic rearrangement of aryloxiranes. The zeolites can be easily removed from reaction mixts. by filtration and regenerated by heating and can then be reused several times to give the same selectivity. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Smith, K.M. PY - 2006 TI - Paramagnetic Organometallic Cr(II)/Cr(III) Redox-Active Catalysts SP - 1023-31 KW - Chromium complexes, Nozaki-Hiyama-Kishi reaction AB - A review. The synthesis and reactivity of well-defined paramagnetic organometallic complexes of the first-row transition metals is an area of increasing research, as new applications of these species are discovered. While most inorg. chemists studying paramagnetic organochromium compds. have been investigating their application for olefin polymn., redox-active chromium catalysts have been developed for C-C bond forming reactions for org. synthetic applications. In particular, a variety of chiral ligands have been introduced for the coupling of org. halides and aldehydes by chromium reagents, the Nozaki-Hiyama-Kishi (NHK) reaction. This article describes some of the coordination chem. of Cr(II) and Cr(III) that led to these asym. NHK catalysts and that continues to underpin the unique reactivity profile of these reagents, as well as reviewing recent progress in the development of these and other paramagnetic organometallic catalysts based on more than one oxidn. state of chromium. JO - Coordination Chemistry Reviews VL - 250 ER - TY - JOUR AU - Somei, M. AU - Iwaki, T. AU - Yamada, F. AU - Tanaka, Y. AU - Shigenobu, K. AU - Koike, K. AU - Suzuki, N. AU - Hattori, A. PY - 2006 TI - The Chemistry of Indoles. Part 128. The Ideal Synthetic Method Aimed at the Leads for an .a.2-Blocker, an Inhibitor of Blood Platelet Aggregation, and an Anti-Osteoporosis Agent SP - 1565-9 KW - Indoles, tryptamine derivatives AB - A review. According to the definition of the ideal synthetic method, an example aimed at the leads for an .a.2-blocker, an inhibitor of platelet aggregation, and an anti-osteoporosis agent was established starting from tryptamine. The originality rate, the intellectual property, and the application potential factors of the method are 71, 54, and 100, resp. The method employs only conventional reagents and reaction conditions without using any protecting groups. JO - Heterocycles VL - 68 ER - TY - JOUR AU - Stanovnik, B. AU - Tisler, M. AU - Katritzky, A.R. AU - Denisko, O.V. PY - 2006 TI - The Tautomerism of Heterocycles: Substituent Tautomerism of Six-Membered Ring Heterocycles SP - 1-134 KW - Heterocycles, tautomerism AB - A review covering compds. with one or more potentially tautomeric functional groups in oxo-hydroxy, thiono-mercapto, amino-imino and methylene tautomerism. JO - Advances in Heterocyclic Chemistry ER - TY - JOUR AU - Suginome, M. PY - 2006 TI - Aminoboranes as New Iminium Ion Generators in Amination Reactions SP - 1377-87 KW - Aminoboranes AB - A review describes the utilization of aminoborane derivs. in amination reactions such as Strecker-type aminative cyanation, Mannich-type reaction, and reductive amination developed in this research group. Bis(dialkylamino)cyanoboranes and bis(dialkylamino)boron enolates undergo the concurrent transfer of the amino group and either the cyano or the enoxy group from the boron to carbonyl carbon atom in their reaction with aldehydes, leading to the formation of .a.-amino nitriles and .b.-amino ketones, resp. Bis(dialkylamino)borane derivs. that lack the addnl. nucleophilic groups on the boron atoms serve as effective generators of iminium ions from aldehydes. In the presence of these aminoboranes, reactions of aldehydes with ketene silyl acetals or silyl enol ethers take place, giving Mannich-type products, i.e., .b.-amino esters and ketones, selectively. Using diisopropylamino-substituted boron compds., which are designed as "universal" iminium ion generators, reactions of free sec-amines, aldehydes, and ketene silyl acetals proceed efficiently, giving .b.-amino esters in which the amino groups are derived exclusively from the free amines. The use of the universal iminium ion generator is also effective for reductive amination of aldehydes, in which NaBH4 is used as a hydride donor. JO - Pure and Applied Chemistry VL - 78 ER - TY - JOUR AU - Suponitsky, K.Y. AU - Timofeeva, T.V. AU - Antipin, M.Y. PY - 2006 TI - Molecular and Crystal Design of Nonlinear Optical Organic Materials SP - 457-96 KW - Optical organic materials AB - A review. The results of theor. and exptl. studies on the second-order mol. and crystal nonlinear optical susceptibilities of org. and several classes of organoelement compds. are summarized. Modern methods used in these studies are briefly characterized, their advantages and drawbacks are outlined as regards their application to the systematic search for efficient nonlinear optical materials. Recent achievements and the main challenges in the field are thoroughly discussed and an optimum algorithm of the design of such materials is proposed. JO - Russian Chemical Reviews VL - 75 ER - TY - JOUR AU - Szabo, K.J. PY - 2006 TI - Palladium-Pincer-Complex-Catalyzed Transformations Involving Organometallic Species SP - 811-24 KW - Palladium pincer complex AB - A review. Highly selective palladium-catalyzed transformations involving organoboranes, silanes, stannanes and selenides were developed by employment of pincer-complex catalysts. A novel catalytic transformation was designed for allylation of aldehyde and imine electrophiles using allylstannanes and allylboranes. These reactions proceed under mild and neutral conditions to afford homoallyl alcs. and amines with a high level of functional group tolerance. The regio- and stereoselectivity of the transformations is very high, and promising levels of enantioselectivity could be obtained by application of chiral pincer complexes. The rest of the presented reactions involve synthesis of allylstannanes, allylboranes, allenyl stannanes/silanes and organoselenides using various dimetallic reagents. Most of the presented pincer-complex-catalyzed reactions are not amenable with traditional palladium(0) catalysis. The employed mild and neutral reaction conditions allow the isolation of stereo- and regiodefined organometallic species, which are useful building blocks in advanced org. synthesis and in natural product synthesis. The mechanistic studies have revealed some important differences between the mechanism of pincer-complex-catalyzed and palladium(0)-catalyzed processes. JO - Synlett ER - TY - JOUR AU - Tantillo, D.J. AU - Hoffmann, R. PY - 2006 TI - Snakes and Ladders. The Sigmatropic Shiftamer Concept SP - 477-86 KW - Sigmatropic shiftamers AB - A review. Sigmatropic shiftamers are org. mols. (conceived originally as polymers) in which bonds migrate back and forth along their frameworks. In this Account, we describe the origins of the sigmatropic shiftamer concept, theor. predictions of mol. architectures that may support shiftamer behavior, and possible future directions for research on this class of mols. JO - Accounts of Chemical Research VL - 39 ER - TY - JOUR AU - Tidwell, T.T. PY - 2006 TI - Blue, But Not a Mirage: Stable Aminoketenes by Carbene Carbonylation SP - 5580-2 KW - Aminoketenes, by carbene carbonylation Ketenes, HOMO-LUMO interactions AB - A review. A true oasis: The prepn. of the first isolable aminoketenes by carbon monoxide addn. to nitrogen-substituted carbenes fills a void in ketene chem. in unexpected ways, and further provides a visual demonstration of ketene HOMO-LUMO interactions. JO - Angewandte Chemie, International Edition VL - 45 ER - TY - JOUR AU - Togo, H. AU - Iida, S. PY - 2006 TI - Synthetic Use of Molecular Iodine for Organic Synthesis SP - 2159-75 KW - Iodine, molecular AB - A review. The synthetic use of mol. iodine is described. Iodine is a universal oxidizing agent, esp. for the oxidn. of alcs. and aldehydes to esters, nitriles and amides. Further applications are the introduction of protecting groups, deprotection, iodocyclization, C-C bond formation, and formation of heterocycles. JO - Synlett ER - TY - JOUR AU - Toniolo, C. AU - Formaggio, F. AU - Kaptein, B. AU - Broxterman, Q.B. PY - 2006 TI - You are Sitting on a Gold Mine! SP - 1295-310 KW - Amino acids, .a.,.a.-disubstituted AB - A review. The synthesis of peptides heavily based on C.a.,.a.-disubstituted .a.-amino acids, such as H2NC(Me)2CO2H (Aib), is a rather difficult task as the reactivity of these building blocks in amide bond formation is generally poor, which primarily results from the severe steric hindrance of the .a.-amino functionality. Nevertheless, such a synthetic approach is very relevant in view of the current extensive utilization of these peptides as membrane-active, antimicrobial, compds. and conformationally restricted, tunable, spacers and templates in modern org. and phys. chem. investigations. In this review, we discuss new mechanistic information, drawbacks, improvements, and successful results published over the years by a no. of research groups with special emphasis on the problems encountered and (often) solved in our own journey through this fascinating field. JO - Synlett ER - TY - JOUR AU - Trost, B.M. AU - Machacek, M.R. AU - Aponick, A. PY - 2006 TI - Predicting the Stereochemistry of Diphenylphosphino Benzoic Acid (DPPBA)-Based Palladium-Catalyzed Asymmetric Allylic Alkylation Reactions: A Working Model SP - 747-60 KW - Diphenylphosphino benzoic acid Allylic alkylation, asymmetric, Pd AB - A review. Palladium-catalyzed asym. allylic alkylation has proven to be a powerful method for the prepn. of a wide variety of chiral compds. and the rapid assembly of complex mol. architecture from simple starting materials. While many types of catalyst systems have been successfully employed with certain systems, diphenylphosphino benzoic acid (DPPBA) based ligands have found use over a broad range of substrate classes. This Account highlights the mechanistic aspects considered when designing reactions with DPPBA-based ligands and presents a working model for the a priori prediction of their stereochem. outcome. JO - Accounts of Chemical Research VL - 39 ER - TY - JOUR AU - Tsuzuki, S. AU - Uchimaru, T. PY - 2006 TI - Magnitude and Physical Origin of Intermolecular Interactions of Aromatic Molecules: Recent Progress of Computational Studies SP - 745-62 KW - Aromatics, computational chemistry AB - A review. Intermol. interactions of arom. mols. (.p./.p., OH/.p., NH/.p. and cation/.p. interactions) are important in many fields of chem. and biol. These interactions are important for crystal structures, stability of biol. systems and their mol. recognition processes. Detailed information on the interactions of arom. mols. is essential for improved material and drug design. However it is not an easy task to study the magnitude and phys. origin of these interactions by exptl. measurements only. Recent developments of computational methodologies and increasing computer performance enable us to study these interactions quant. by high-level ab initio MO calcns. High-level ab initio calcns. are rapidly increasing our knowledge on the intermol. interactions of arom. mols. This review attempts to introduce methodologies for studying weak intermol. interactions by ab initio calcns. and to summarize recent progress in quant. anal. of intermol. interactions of arom. mols. JO - Current Organic Chemistry VL - 10 ER - TY - BOOK AU - Uneyama, K. AU - Ed PY - 2006 BT - Organofluorine Chemistry CY - Oxford, U.K. PB - Blackwell SP - 339 KW - Organofluorines, book ER - TY - JOUR AU - Vaillancourt, F.H. AU - Yeh, E. AU - Vosburg, D.A. AU - Garneau-Tsodikova, S. AU - Walsh, C.T. PY - 2006 TI - Nature's Inventory of Halogenation Catalysts: Oxidative Strategies Predominate SP - 3364-78 KW - Halogenation enzymes Haloperoxidases Fluorinating enzymes AB - A review dealing with fluorinating enzymes, oxidative logic in JO - Chemical Reviews VL - 106(8) ER - TY - JOUR AU - Valentine, J.C. AU - McDonald, F.E. PY - 2006 TI - Biomimetic Synthesis of Trans,Syn,Trans-Fused Polycyclic Ethers SP - 1816-28 KW - Polycyclic ethers AB - A review. This account describes potentially biomimetic tandem regio- and stereoselective oxa-cyclizations of acyclic polyepoxide substrates to provide trans,syn,trans-fused polycyclic ether structures, as found in marine natural products exemplified by brevetoxins, ciguatoxins, and maitotoxin. JO - Synlett ER - TY - JOUR AU - Van Ornum, S.G. AU - Champeau, R.M. AU - Pariza, R. PY - 2006 TI - Ozonolysis Applications in Drug Synthesis SP - 2990-3001 KW - Ozonolysis, in drug synthesis Artemisinin, synthesis AB - A review. The application of ozonolysis in the total synthesis of artemisinin, indolizidine 251F, DL-camptothecin, 24(S)-hydroxyvitamin-D2 was discussed. Industrial-scale ozonolysis applied toward the synthesis of ceftibuten and cefaclor, 2-hydroxyindan-2-carboxaldehyde, oxandrolone was reviewed. JO - Chemical Reviews VL - 106(7) ER - TY - JOUR AU - Varchi, G. AU - Ojima, I. PY - 2006 TI - Synthesis of Heterocycles through Hydrosilylation, Silylformylation, Silylcarbocyclization and Cyclohydrocarbonylation Reactions SP - 1341-62 KW - Heterocycles, via hydrosilylation Heterocycles, via silylformylation Heterocycles, via silylcarbocyclization Heterocycles, via cyclohydrocarbonylation AB - A review. The design and development of highly efficient catalytic methods for the synthesis of carbocycles and heterocycles was the subject of extensive study, because of their relevance to life sciences and material sciences. Among various available synthetic methods, the transition-metal-catalyzed cyclization reactions has attracted much attention for the transformation of simple starting materials into heterocyclic scaffolds, which can be further elaborated into more specific targets. Accordingly, this review describes recent advances in the synthesis of heterocycles by intramol. hydrosilylation, intramol. silylformylation, silylcarbocyclization (SiCaC), and cyclohydrocarbonylation reactions. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Varela, J.A. AU - Saa, C. PY - 2006 TI - Pericyclic Reactions Involving Catalytic Metal-Vinylidene Complexes SP - 6450-6 KW - Pericyclic reactions, metal-vinylidenes Metal-vinylidenes AB - A review. The formation of complex polycyclic systems from terminal alkynes based on the concept of pericyclic reactions of catalytic metal-vinylidenes is presented. Metal-vinylidenes, easily formed from terminal alkynes with catalytic amts. of several metal complexes, can be used in electrocyclizations, cycloaddns. or sigmatropic rearrangements to afford valuable compds. JO - Chemistry--A European Journal VL - 12 ER - TY - JOUR AU - Vasapollo, G. AU - Mele, G. PY - 2006 TI - Synthesis of Heterocycles by Transition Metal-Catalyzed Cyclocarbonylation Reactions SP - 1397-421 KW - Lactones, via cyclocarbonylation Lactams, via cyclocarbonylation Pyrrolidinones, via cyclocarbonylation AB - A review. The synthesis of heterocyclic compds. such as lactones, lactams, pyrrolidinones and others can be achieved by cyclocarbonylation reactions catalyzed by transition metal complexes. The combination of Pd salts with certain different ligands turned out to be the most efficient catalyst systems to accomplish such cyclocarbonylation reactions. New synthetic strategies and novel approaches devoted to the prepn. of such compds. having different ring size still remain a stimulating area of academic and industrial research. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Vatsadze, S.Z. AU - Nuriev, V.N. AU - Zyk, N.V. PY - 2005 TI - Synthesis of Azoles with Two Pyridine Substituents at Carbon Atoms and Their Use in Coordination Chemistry SP - 1091-101 KW - Azoles, two pyridine substituents AB - A review (57 refs.). Published data on the synthesis of azoles contg. two pyridine substituents were analyzed in relation to the type of central five-membered ring. The applications of such mols. as ligands in coordination chem. were discussed. JO - Chemistry of Heterocyclic Compounds VL - 41(9) ER - TY - JOUR AU - Vicario, J.L. AU - Badia, D. AU - Carrillo, L. AU - Etxebarria, J. AU - Reyes, E. AU - Ruiz, N. PY - 2005 TI - The Asymmetric Aza-Michael Reaction. A Review SP - 513-38 KW - Aza-Michael reaction, asymmetric AB - A review discusses various methodologies reported for performing stereocontrolled aza-Michael reactions. These methods are subdivided to (i) reactions using chiral auxiliaries, (ii) reactions with chiral nucleophiles, (iii) reactions in the presence of chiral ligands, and (iv) catalytic asym. aza-Michael reactions. JO - Organic Preparations and Procedures International VL - 37 ER - TY - JOUR AU - Voit, B. PY - 2006 TI - Sequential One-Pot Reactions Using the Concept of "Site Isolation" SP - 4238-40 KW - Heterogeneous catalysts, site-isolation Heterogeneous catalysts, multistep AB - A review. Acidic and basic sites can be isolated by incorporation in the core of star-shaped polymers. J. M. J. Frechet (2005) et al. have used these polymer-based catalysts for homogeneous-phase one-pot multistep reactions. Similarly, K. Kaneda et al. (2004, 2005) have demonstrated the site-isolation concept in heterogeneous systems by use of different types of layered clays. JO - Angewandte Chemie, International Edition VL - 45 ER - TY - JOUR AU - Voitekhovich, S.V. AU - Gaponik, P.N. AU - Koldobskii, G.I. PY - 2005 TI - Organometallic Tetrazole Derivatives: Preparation and Application to Organic Synthesis SP - 1565-82 KW - Tetrazoles AB - A review. The data are integrated and systematized on prepn. procedures and application to the org. synthesis of organometallic tetrazole derivs., including 5-metalated tetrazoles and tetrazoles with a metal-carbon bond in a substituent, and also organotin tetrazoles. JO - Russian Journal of Organic Chemistry VL - 41 ER - TY - JOUR AU - Walton, J.C. PY - 2006 TI - Unusual Radical Cyclizations SP - 163-200 KW - Radical cylization AB - A review. Methods for solving the problems assocd. with reverse ring opening of small-ring intermediates are described. For three- and four-membered rings particular patterns of substituents are required. Rapid methods of trapping small cyclic structures and extg. them from unfavorable equil. depend on special new reagents. The new methods enable mono- and polycyclic cyclopropanes and cyclobutanes contg. a range of functionality to be readily prepd. Also, several of the newer reagents allow a good measure of stereocontrol to be exercised. Mols. contg. the azetidinone ring system (.b.-lactam) were made by no less than four different radical-based disconnections. Syntheses of medium-sized rings invoke endo-type cyclizations and are favored by precursors contg. electron-withdrawing groups at the terminus of the radical acceptor group. Promising routes to seven- and eight-membered lactams are described as well as to 11- and 12-membered lactams. Alternative radical-based strategies for making rings by intramol. cyclo-dimerizations of diradicals and by intramol. cyclo-coupling of radicals with carbanionic centers are included. JO - Topics in Current Chemistry VL - 264 ER - TY - JOUR AU - Wang, S.C. AU - Tantillo, D.J. PY - 2006 TI - Metal Promoted Vinylcyclopropane-Cyclopentene Rearrangements: Reactions Ripe for Mechanism-Based Catalyst Design SP - 4386-92 KW - Vinylcyclopropane-cyclopentene rearrangements AB - This brief review describes exptl. and theor. data relevant to the mechanisms of transition metal promoted vinylcyclopropane-cyclopentene rearrangements. In particular, reactions utilizing Pd(0), Rh(I), and Ni(0) are highlighted and compared to analogous reactions not involving transition metals. JO - Journal of Organometallic Chemistry VL - 691 ER - TY - JOUR AU - Weidenbruch, M. PY - 2006 TI - A Stable Silylenoid and a Donor-Stabilized Chlorosilylene: Low-Coordinate Silicon Compounds - A Never-Ending Story? SP - 4241-2 KW - Silicon-halogen compounds AB - A review. Since prepn. of the first stable mol. contg. an Si-Si double bond more than 50 compds. with this structural constituent have been described. Silylenoids contg. a silicon-halogen bond have been prepd. and should form the basis of interesting subsequent chem. JO - Angewandte Chemie, International Edition VL - 45 ER - TY - JOUR AU - Weinreb, S.M. PY - 2006 TI - Studies on Total Synthesis of the Cylindricine/Fasicularin/Lepadiformine Family of Tricyclic Marine Alkaloids SP - 2531-49 KW - Alkaloids, marine, tricyclic AB - A review. Studies on the total syntheses of tricyclic marine alkaloids in the cylindricine/fasicularin/lepadiformine family are reviewed. JO - Chemical Reviews VL - 106(6) ER - TY - JOUR AU - Wiklund, P. AU - Bergman, J. PY - 2006 TI - The Chemistry of Anthranilic Acid SP - 379-402 KW - Anthranilic acid Aminobenzoic acid Alkaloids, synthesis, with aminobenzoic acid AB - A review. Anthranilic acid (2-aminobenzoic acid, AA) is a versatile and low cost starting material for synthesis of benzo-fused heterocycles. It also plays a vital part in the biosynthesis of tryptophan and its derivs., as well as in several types of alkaloids. Therefore the chem. of anthranilic acid is of importance in medicinal and biol. chem. The main emphasis of this review article is on the use of anthranilic acid as a starting material for synthesis of heterocycles, but it also covers the history, synthesis and reactivity, as well as a short account of the medicinal chem. and biochem. of anthranilic acids. JO - Current Organic Synthesis VL - 3 ER - TY - JOUR AU - Wu, G. AU - Huang, M. PY - 2006 TI - Organolithium Reagents in Pharmaceutical Asymmetric Processes SP - 2596-616 KW - Organolithium reagents AB - A review. The applications of organolithium reagents in stereoselective alkylation, chiral auxiliary-mediated alkylation, intramol. alkylation, nucleophilic addn., alkynylation of imines and ketones, aldol condensation, Lewis acid-promoted condensation, conjugate addn., Michael reaction, and other aspects of asym. synthesis were discussed. JO - Chemical Reviews VL - 106(7) ER - TY - JOUR AU - Wu, J. AU - Chan, A.S.C. PY - 2006 TI - P-Phos: A Family of Versatile and Effective Atropisomeric Dipyridylphosphine Ligands in Asymmetric Catalysis SP - 711-20 KW - Atropisomeric dipyridylphosphine ligands AB - A review. This review outlines our efforts in the design and synthesis of a family of highly effective atropisomeric dipyridylphosphine ligands (P-Phos and its variants) and in the development of their widespread applications in transition-metal-catalyzed asym. reactions including hydrogenation, hydrosilylation, and C-C bond formation. Desirable attributes, such as air stability, broad substrate scope, fast rates of reaction, excellent enantioselectivities, low catalyst loading, and mild JO - Accounts of Chemical Research VL - 39 ER - TY - JOUR AU - Yam, V.W.-W. AU - Wong, K.M.-C. PY - 2005 TI - Luminescent Molecular Rods - Transition-Metal Alkynyl Complexes SP - 1-32 KW - Luminescent complexes AB - A review. A no. of transition-metal complexes are reported to exhibit rich luminescence, usually originating from phosphorescence. Such luminescence properties of the triplet excited state with a large Stoke's shift, long lifetime, high luminescence quantum yield as well as lower excitation energy, are envisaged to serve as an ideal candidate in the area of potential applications for chemosensors, dye-sensitized solar cells, flat panel displays, optics, new materials and biol. sciences. Org. alkynes (poly-ynes), with extended or conjugated .p.-systems and rigid structure with linear geometry, have become a significant research area due to their novel electronic and phys. properties and their potential applications in nanotechnol. Owing to the presence of unsatd. sp-hybridized C atoms, the alkynyl unit can serve as a versatile building block in the construction of alkynyl transition-metal complexes, not only through .s.-bonding but also via .p.-bonding interactions. By incorporation of linear alkynyl groups into luminescent transition-metal complexes, the alkynyl moiety with good .s.-donor, .p.-donor and .p.-acceptor abilities is envisaged to tune or perturb the emission behaviors, including emission energy (color), intensity and lifetime by its role as an auxiliary ligand as well as to govern the emission origin from its direct involvement. This review summarizes recent efforts on the synthesis of luminescent rod-like alkynyl complexes with different classes of transition metals and details the effects of the introduction of alkynyl groups on the luminescence properties of the complexes. JO - Topics in Current Chemistry VL - 257 ER - TY - JOUR AU - Yamaguchi, S. AU - Wakamiya, A. PY - 2006 TI - Boron as a Key Component for New .p.-Electron Materials SP - 1413-24 KW - Boron, .p.-conjugated AB - A review of the mol. design of .p.-electron materials; the incorporation of main group elements into the .p.-conjugated frameworks is a powerful approach to modifying the nature of the parent .p.-conjugated systems. In particular, the group 13 B is of interest, since the B element has several characteristic features, such as an effective orbital interaction with the .p.-conjugated frameworks through the vacant p-orbital (i.e., p.p.-.p.* conjugation), high Lewis acidity, and trigonal planar geometry. By exploiting these features of the B atom, several types of new .p.-electron materials have been designed and synthesized, including trianthrylborane- or dibenzoborole-based .p.-conjugated systems as a new F- ion sensor, boryl-substituted thienylthiazole as a new building unit for electron-transporting materials, and B,B',B''-trianthrylborazine (B3N3)-based materials as a model of the bundled system of .p.-conjugated frameworks. JO - Pure and Applied Chemistry VL - 78 ER - TY - JOUR AU - Yamamoto, Y. AU - Yamamoto, H. PY - 2006 TI - Recent Advances in Asymmetric Nitroso Diels-Alder Reactions SP - 2031-43 KW - Diels-Alder reactions, nitroso- AB - A review. During the past decade, the nitroso Diels-Alder (NDA) reaction has become a more practical tool for org. synthesis, and a no. of important compds. have been synthesized using this method. Until recently, no reports on a catalytic asym. version of this reaction had been reported; the major issues were the high reactivity of nitroso compds. and their chem. properties. This microreview outlines recent advances in the area of asym. NDA reaction following the review by Streith and Defoin in 1994. JO - European Journal of Organic Chemistry ER - TY - JOUR AU - You, S.-L. AU - Dai, L.-X. PY - 2006 TI - Enantioselective Palladium-Catalyzed Decarboxylative Allylic Alkylations SP - 5246-8 KW - Decarboxylative allylic alkylations Ketones, enantioenriched AB - A review discusses the recent developments in palladium-catalyzed decarboxylative asym. allylic alkylation reactions, which provide an easy access to highly enantioenriched ketones with .a.-positioned quaternary or tertiary carbon stereocenters under mild conditions. JO - Angewandte Chemie, International Edition VL - 45 ER - TY - JOUR AU - Yus, M. AU - Foubelo, F. PY - 2006 TI - Homologation of Heterocycles by a Sequential Reductive Opening Lithiation-Electrophilic Substitution-Cyclization SP - 135-58 KW - Heterocycles, substituted, using Li AB - A review covering the application of the title reactions to oxetanes, thietanes, tetrahydrofurans, tetrahydrothiophenes, phthalan, thiophthalan, 2,3-dihydrobenzofuran, 2,3-dihydrobenzothiophene, 2,3-benzofuran, isochroman, thioisochroman, phenoxathiin, phenothiazine, thianthrene, 1H,3H-benzo[de]isochromene, and 2,7-dihydrobenzothiepine and their derivs. JO - Advances in Heterocyclic Chemistry ER - TY - JOUR AU - Yutilov, Y.M. PY - 2005 TI - Imidazopyridines: 1- and 3-Deazapurines SP - 159-270 KW - Imidazopyridines Deazapurines AB - A review covering the syntheses and chem. and other properties of imidazo[4,5-b]pyridines and imidazo[4,5-c]pyridines and their derivs. JO - Advances in Heterocyclic Chemistry ER - TY - BOOK AU - Zaragoza, D.F. PY - 2004 BT - Side Reactions in Organic Synthesis: A Guide to Successful Synthesis Design CY - Weinheim, Germany PB - Wiley-VCH Verlag SP - 374 KW - Synthesis, side reactions, book ER - TY - JOUR AU - Zhang, W. AU - Moore, J.S. PY - 2006 TI - Shape-Persistent Macrocycles: Structures and Synthetic Approaches from Arylene and Ethynylene Building Blocks SP - 4416-39 KW - Macrocyles, shape-persistent Macrocyclic alkynes AB - A review discusses the prepn. of shape-persistent macrocycles, particularly macrocyclic alkynes; the characteristics and uses of kinetic and thermodynamically-driven macrocyclization reactions in the prepn. of shape-persistent macrocycles are discussed. JO - Angewandte Chemie, International Edition VL - 45 ER - TY - JOUR AU - Zhang, Z. AU - Zhu, G. AU - Tong, X. AU - Wang, F. AU - Xie, X. AU - Wang, J. AU - Jiang, L. PY - 2006 TI - Transition Metal-Catalyzed Intramolecular Enyne Cyclization Reaction SP - 1457-78 KW - Enyne cyclization AB - A review which summarizes the recent developments in transition metal-catalyzed 1,n-enyne cyclization reactions that are reported in the literature from Jan. 1, 2002 to Apr. 30, 2005. The cyclizations described herein include four parts according the reaction mechanism, i. e. cyclization initiated by oxidative cyclometalation; by activation of the triple bond to form a vinyl metal species; by electrophilic activation of the triple bond; and by activation of the double bond. Enyne cyclizations that do not follow the above reaction mechanism are not included. JO - Current Organic Chemistry VL - 10 ER - TY - JOUR AU - Zheng, J. AU - Kwak, K. AU - Xie, J. AU - Fayer, M.D. PY - 2006 TI - Ultrafast Carbon-Carbon Single-Bond Rotational Isomerization in Room-Temperature Solution SP - 1951-5 KW - C-C bond, rotational isomerization AB - Generally, rotational isomerization about the carbon-carbon single bond in simple ethane derivs. in room-temp. soln. under thermal equil. conditions has been too fast to measure. We achieved this goal using two-dimensional IR vibrational echo spectroscopy to observe isomerization between the gauche and trans conformations of an ethane deriv., 1-fluoro-2- isocyanatoethane (1), in a CCl4 soln. at room temp. The isomerization time const. is 43 ps (ps, 10-12 s). Based on this value and on d. functional theory calcns. of the barrier heights of 1, n-butane, and ethane, the time consts. for n-butane and ethane internal rotation under the same conditions are ?40 and ?12 ps, resp. JO - Science VL - 313(5795) ER - TY - JOUR AU - Zimmerman, J. AU - Sibi, M.P. PY - 2006 TI - Enantioselective Radical Reactions SP - 107-62 KW - Radical reactions AB - A review. Over the past two decades, many researchers have been interested in "taming" the reactive free radical intermediate and utilizing it in enantioselective transformations. This review highlights the substantial progress made in this area of synthetic org. chem. The main classes of radical reactions that have received the most attention include atom transfer, conjugate addn., addn. and trapping, and electron transfer reactions. Also, the possibility of establishing multiple stereocenters in one simple transformation makes enantioselective free radical chem. a very attractive tool for org. chemists. JO - Topics in Current Chemistry VL - 263 ER - TY - JOUR AU - Zipse, H. PY - 2006 TI - Radical Stability - A Theoretical Perspective SP - 163-89 KW - Radicals, stability AB - A review. The thermodn. stability of radicals as defined through isodesmic hydrogen transfer reactions was explored at a variety of theor. levels. Radical stabilization energies (RSEs) derived from single point calcns. at the ROMP2/ 6-311+G(3df,2p)//UBecke3LYP/6-31G(d) level of theory in combination with scaled zero point vibrational energies calcd. at the UBecke3LYP/6-31G(d) level were detd. for a broad variety of systems. For the three radical types considered in this study (carbon-, nitrogen-, and oxygen-centered radicals) the radical stabilization energy (RSE) depends on the same fundamental effects such as resonance stabilization of the unpaired spin, electron donation through adjacent alkyl groups or lone pairs, and through inductive electron donation/electron withdrawal. The influence of ring strain effects as well as the synergistic combination of individual substituent effects also were explored. JO - Topics in Current Chemistry VL - 263 ER - TY - JOUR AU - Zsigmond, A. AU - Notheisz, F. PY - 2006 TI - Selective Syntheses on Heterogenized Metal Complexes SP - 1655-80 KW - Heterogenized metal complexes AB - A review. The prepn. and application of heterogenized metal complexes is a relatively new field of research resulting in a new way of catalysis, that we cannot realize either with traditional homogeneous or heterogeneous catalysts. The heterogenized metal complexes can successfully combine the excellent performance (high activity and selectivity) of homogeneous catalysts with the easy sepn. and recycling of the heterogeneous catalysts. Addnl., in several cases the immobilization of metal complexes leads to enhanced stereo-, chemo- and enantioselectivity, interpreted by a mechanism related to the "confinement concept". This review gives a summary of the different ways of prepn. of heterogenized metal complexes on inorg. matrixes and shows some applications of such catalysts in synthetic org. chem. JO - Current Organic Chemistry VL - 10 ER -