Author: Ivory Derrick Hills
Publisher:
ISBN:
Category :
Languages : en
Pages : 376
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Book Description
In Part I the development of a new method for the construction of oxindoles and benzofuranones bearing quaternary stereocenters is discussed. A planar-chiral PPY derivative catalyzes the O-to-C acyl group migration (Black rearrangement) in a highly efficient and enantioselective manner. The utility of this method is further demonstrated by the formal total synthesis of the natural product aplysin. In Part II reactivity of bisphosphine palladium-complexes is discussed. It is shown that the oxidative addition of bisphosphine palladium-complexes bearing P(t-Bu2)Me occurs through an SN2-type mechanism. This discovery allows us rationalize the difference in catalytic activity between Pd(P(t-Bu2)Me)2 and Pd(P(t-Bu2)Et)2 for the cross-coupling of alkyl electrophiles. The reductive elimination of H-X from bisphosphine palladium-hydride complexes is also discussed. The discovery that (P(t-Bu)3)2PdHCl undergoes facile reductive elimination in the presence of Cy2NMe, while (PCy3)2PdHCl does not, is explained using X-ray crystal structures. These reactivity patterns may help to explain why Pd(P(t-Bu)3)2 is a much better catalyst than Pd(PCy3)2 for the Heck coupling of aryl chlorides. Finally, Part III describes preliminary work on a palladium-hydride catalyzed isomerization of allylic alcohols as well as initial attempts to study the mechanism of nickel-catalyzed cross-couplings of secondary alkyl-electrophiles.
Author: Helene Pellissier
Publisher: John Wiley & Sons
ISBN: 3527346198
Category : Science
Languages : en
Pages : 402
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Book Description
Introduces an innovative and outstanding tool for the easy synthesis of complex chiral structures in a single step Covering all of the literature since the beginning of 2006, this must-have book for chemists collects the major progress in the field of enantioselective one-, two-, and multicomponent domino reactions promoted by chiral metal catalysts. It clearly illustrates how enantioselective metal-catalyzed processes constitute outstanding tools for the development of a wide variety of fascinating one-pot asymmetric domino reactions, thereby allowing many complex products to be easily generated from simple materials in one step. The book also strictly follows the definition of domino reactions by Tietze as single-, two-, as well as multicomponent transformations. Asymmetric Metal Catalysis in Enantioselective Domino Reactions is divided into twelve chapters, dealing with enantioselective copper-, palladium-, rhodium-, scandium-, silver-, nickel-, gold-, magnesium-, cobalt-, zinc-, yttrium and ytterbium-, and other metal-catalyzed domino reactions. Most of the chapters are divided into two parts dealing successively with one- and two-component domino reactions, and three-component processes. Each part is subdivided according to the nature of domino reactions. Each chapter of the book includes selected applications of synthetic methodologies to prepare natural and biologically active products. -Presents the novel combination of asymmetric metal catalysis with the concept of fascinating domino reactions, which allows high molecular complexity with a remarkable level of enantioselectivity -Showcases an incredible tool synthesizing complex and diverse chiral structures in a single reaction step -Includes applications in total synthesis of natural products and biologically active compounds -Written by a renowned international specialist in the field -Stimulates the design of novel asymmetric domino reactions and their use in the synthesis of natural products, pharmaceuticals, agrochemicals, and materials Asymmetric Metal Catalysis in Enantioselective Domino Reactions will be of high interest to synthetic, organic, medicinal, and catalytic chemists in academia and R&D departments.
Author: Aziza Hatice Sahin
Publisher:
ISBN: 9781124223438
Category :
Languages : en
Pages :
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Book Description
In Chapter One, a catalytic enantioselective method for the synthesis of 3- hydroxy-2-oxindoles is described. 3-Hydroxy-2-oxindoles were synthesized by a nucleophilic addition of electron-rich arenes and aromatic heterocycles to substituted indole-2,3-diones (isatins) catalyzed by scandium(III) and indium(III)-inda-pybox complexes. The use of a bulky chiral ligand hindered the formation of the achiral 3,3-diaryl-2-oxindole side product. Substituted 3-hydroxy-2-oxindoles were formed in high yield and high enantioselectivity (up to 99% ee). In Chapter Two, a method for the synthesis of chiral 3,3-disubstituted-2-oxindoles from a nucleophilic substitution at the stereocenter of a substituted 3-hydroxy-2-oxindole is described. This SN̳1-like process is catalyzed by a Lewis or a Brønsted acid, which eliminates water to form an indolenium ion intermediate. Chiral BINOL-derived phosphoric acids and phosphoramides are promising catalysts for an asymmetric process, as the conjugate base can act as a counteranion that coordinates to the carbocation intermediate to direct an asymmetric nucleophilic addition. Catalyst and solvent effects have been investigated with yields ranging from 68-97%. Preliminary enantioselectivity has been observed and further optimization is underway.
Author: Jose L Vicario
Publisher: Royal Society of Chemistry
ISBN: 1849732183
Category : Science
Languages : en
Pages : 365
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Book Description
This book, unique in its field, is a comprehensive description of all the methodologies reported for carrying out conjugate addition reactions in a stereoselective way, using small chiral organic molecules as catalysts (organocatalysts). In the last 3-4 years, this has been a rapidly growing field in organic chemistry, and many papers have appeared reporting excellent protocols for carrying out these highly efficient transformations that compete well with other classical approaches using transition metal catalysts. A particularly attractive feature of this transformation relies upon the fact that the conjugate addition (Michael and Hetero-Michael reactions) is an extraordinarily effective means to initiate cascade processes which result in the formation of complex molecules from very small and simple starting blocks. The book, written by noted experts, covers all recent advances in this hot topic, and provides a good state-of-the-art review for organic chemists working in this field and all those who wish to start projects in this area.
Author: Hélène Pellissier
Publisher: Royal Society of Chemistry
ISBN: 1849739889
Category : Science
Languages : en
Pages : 254
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Book Description
A comprehensive overview of enantioselective multicatalysed tandem reactions involving organocatalysts, transition metals as well as enzymes in all possible combinations.
Author: Peter I. Dalko
Publisher: John Wiley & Sons
ISBN: 3527610952
Category : Science
Languages : en
Pages : 559
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Book Description
In this reference leaders at the forefront of research provide an insight into one of the hottest topics in organic synthesis, focusing on the most important enantioselective reactions. Clearly structured, each entry begins with a concise introduction, including a mechanistic discussion of the reaction, followed by preparative guidelines for newcomers, such as carefully selected working procedures with critical notes for bench chemists, rules of thumb and tips and tricks.
Author: Angela Marinetti
Publisher: World Scientific
ISBN: 9811248443
Category : Science
Languages : en
Pages : 501
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Book Description
This book illustrates the broad field of enantioselective catalysis by highlighting a few topics, out of myriads, with the double aim to typify selected synthetic achievements and future challenges. Eleven research groups have highlighted topics of interest in either organo- or organometallic catalysis, related to their own expertise. For mature fields, these short chapters, far from being exhaustive, show updated overviews including major recent advances and disclose a few prospects. Other chapters focus on upcoming topics in enantioselective catalysis, i.e. on classes of reactions or families of catalysts that are expected to provide appealing synthetic tools when suitably mastered. For all these areas, recent studies demonstrate highly promising perspectives.
Author: Uli Kazmaier
Publisher: Springer
ISBN: 364222749X
Category : Science
Languages : en
Pages : 354
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Book Description
Giovanni Poli, Guillaume Prestat, Frédéric Liron, Claire Kammerer-Pentier: Selectivity in Palladium Catalyzed Allylic Substitution.- Jonatan Kleimark and Per-Ola Norrby: Computational Insights into Palladium-mediated Allylic Substitution Reactions.- Ludovic Milhau, Patrick J. Guiry: Palladium-catalyzed enantioselective allylic substitution.- Wen-Bo Liu, Ji-Bao Xia, Shu-Li You: Iridium-Catalyzed Asymmetric Allylic Substitutions.- Christina Moberg: Molybdenum- and Tungsten-Catalyzed Enantioselective Allylic Substitutions.- Jean-Baptiste Langlois, Alexandre Alexakis: Copper-catalyzed enantioselective allylic substitution.- Jeanne-Marie Begouin, Johannes E. M. N. Klein, Daniel Weickmann, B. Plietker: Allylic Substitutions Catalyzed by Miscellaneous Metals.- Barry M. Trost, Matthew L. Crawley: Enantioselective Allylic Substitutions in Natural Product Synthesis.
Author: Rainer Mahrwald
Publisher: Springer Science & Business Media
ISBN: 9048138671
Category : Science
Languages : en
Pages : 400
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Book Description
Organocatalyzed Reactions I and II presents a timely summary of organocatalysed reactions including: a) Enantioselective C-C bond formation processes e.g. Michael-addition, Mannich-reaction, Hydrocyanation (Strecker-reaction), aldol reaction, allylation, cycloadditions, aza-Diels-Alder reactions, benzoin condensation, Stetter reaction, conjugative Umpolung, asymmetric Friedel-Crafts reactions; b) Asymmetric enantioselective reduction processes e.g. Reductive amination of aldehydes or ketones, asymmetric transfer hydrogenation; c) Asymmetric enantioselective oxidation processes; d) Asymmetric epoxidation, Bayer-Villiger oxidation; e) Enantioselective a-functionalization; f) A-alkylation of ketones, a-halogenation and a-oxidation of carbonyl compounds.
Author: Rainer Mahrwald
Publisher: Springer Science & Business Media
ISBN: 9048138655
Category : Science
Languages : en
Pages : 333
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Book Description
Organocatalyzed Reactions I and II presents a timely summary of organocatalysed reactions including: a) Enantioselective C-C bond formation processes e.g. Michael-addition, Mannich-reaction, Hydrocyanation (Strecker-reaction), aldol reaction, allylation, cycloadditions, aza-Diels-Alder reactions, benzoin condensation, Stetter reaction, conjugative Umpolung, asymmetric Friedel-Crafts reactions; b) Asymmetric enantioselective reduction processes e.g. Reductive amination of aldehydes or ketones, asymmetric transfer hydrogenation; c) Asymmetric enantioselective oxidation processes; d) Asymmetric epoxidation, Bayer-Villiger oxidation; e) Enantioselective a-functionalization; f) A-alkylation of ketones, a-halogenation and a-oxidation of carbonyl compounds.
