Download or read book Asymmetric C C Bond Formation with Chiral Catalysts written by Menapara Tusharkumar and published by Alibaba. This book was released on 2023-05-25 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book "Asymmetric C-C Bond Formation with Chiral Catalysts" by Menapara Tusharkumar explores the fascinating field of asymmetric catalysis for carbon-carbon bond formation reactions. The book emphasizes on the use of chiral catalysts for the synthesis of enantiopure compounds that are critical for the development of new drugs, agrochemicals, and materials. The use of chiral catalysts offers high enantioselectivity and stereoselectivity, and therefore, provides an efficient way for the synthesis of organic compounds with desired stereochemistry. The book covers the design and synthesis of chiral catalysts, including ligands and transition metal complexes. The author discusses the chemical properties of chiral catalysts and their influence on the reaction mechanisms and stereoselectivity. The book also highlights the importance of molecular recognition in asymmetric catalysis and its application in various catalytic reactions. The book covers various types of asymmetric catalysis, including organocatalysis, metal-catalyzed reactions, and enzymatic catalysis. It discusses the advantages and limitations of each type of catalysis and provides examples of their applications in organic synthesis. The author also emphasizes the importance of green chemistry and sustainability in asymmetric catalysis. The book covers a range of topics related to asymmetric C-C bond formation, including diastereoselectivity, substrate specificity, kinetic resolution, and stereochemical control. The book also provides examples of the synthesis of natural products, alkene coupling, palladium-catalyzed cross-coupling reactions, oxidative coupling reactions, Diels-Alder reactions, and Michael addition reactions using chiral catalysts. Overall, "Asymmetric C-C Bond Formation with Chiral Catalysts" is an essential reference for organic chemists, catalysis researchers, and students who are interested in asymmetric catalysis, enantioselective synthesis, and stereochemistry. The book provides a comprehensive overview of the field, including recent advances and challenges, and offers practical guidance for the design and optimization of chiral catalysts for asymmetric C-C bond formation reactions.

Download or read book Catalytic Asymmetric Synthesis written by Takahiko Akiyama and published by John Wiley & Sons. This book was released on 2022-06-15 with total page 798 pages. Available in PDF, EPUB and Kindle. Book excerpt: Catalytic Asymmetric Synthesis Seminal text presenting detailed accounts of the most important catalytic asymmetric reactions known today This book covers the preparation of enantiomerically pure or enriched chemical compounds by use of chiral catalyst molecules. While reviewing the most important catalytic methods for asymmetric organic synthesis, this book highlights the most important and recent developments in catalytic asymmetric synthesis. Edited by two well-qualified experts, sample topics covered in the work include: Metal catalysis, organocatalysis, photoredox catalysis, enzyme catalysis C–H bond functionalization reactions Carbon–carbon bond formation reactions, carbon–halogen bond formation reactions, hydrogenations, polymerizations, flow reactions Axially chiral compounds Retaining the best of its predecessors but now thoroughly up to date with the important and recent developments in catalytic asymmetric synthesis, the 4th edition of Catalytic Asymmetric Synthesis serves as an excellent desktop reference and text for researchers and students, from upper-level undergraduates all the way to experienced professionals in industry or academia.

Download or read book New Frontiers in Asymmetric Catalysis written by Koichi Mikami and published by John Wiley & Sons. This book was released on 2007-05-04 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: A compilation of recent advances and applications in asymmetric catalysis The field of asymmetric catalysis has grown rapidly and plays a key role in drug discovery and pharmaceuticals. New Frontiers in Asymmetric Catalysis gives readers a fundamental understanding of the concepts and applications of asymmetric catalysis reactions and discusses the latest developments and findings. With contributions from preeminent scientists in their respective fields, it covers: * "Rational" ligand design, which is critically dependent on the reaction type (reduction, oxidation, and C-C bond formation) * Recent findings on activation of C-H bonds, C-C bonds, and small molecules (C=O, HCN, RN=C, and CO2) and the latest developments on C-C bond reorganization, such as metathesis * Advances in "chirally economical" non-linear phenomena, racemic catalysis, and autocatalysis * Some of the recent discoveries that have led to a renaissance in the field of organocatalysis, including the development of chiral Brönstead acids and Lewis acidic metals bearing the conjugate base of the Brönstead acids as the ligands and the chiral bi-functional acid/base catalysts The book ends with a thought-provoking perspective on the future of asymmetric catalysis that addresses both the challenges and the unlimited potential in this burgeoning field. This is an authoritative, up-to-date reference for organic chemists in academia, government, and industries, including pharmaceuticals, biotech, fine chemicals, polymers, and agriculture. It is also an excellent textbook for graduate students studying advanced organic chemistry or chemical synthesis.

Download or read book Development and Evaluation of Chiral Catalysts for Asymmetric C C and C H Bond forming Reactions written by Christian Ebner and published by Cuvillier Verlag. This book was released on 2012-03-05 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work was dedicated to the development and evaluation of new chiral catalysts for asymmetric C-C and C-H bond forming reactions. In the first part of the thesis an ESI-MS screening method is described, which allows the determination of a chiral catalyst´s selectivity in the palladium catalyzed asymmetric allylic alkylation by testing its racemic form. The value of this new method was demonstrated when different new aryl-PHOX-type ligands, which are not easily accessible in their enantiopure form, were evaluated. In the second part new PHOX-type ligands were tested in the iridium-catalyzed asymmetric hydrogenation of different unsaturated compounds. Although low activities and selectivities were found in most cases, one ligand showed promising results in the hydrogenation of allylic alcohols and imines. Furthermore air- and moisture-stable secondary phosphine oxide (SPO) containing bidentate ligands were tested in the palladium-catalyzed asymmetric allylic alkylation reaction. SPO,N-ligands bearing a PHOX type backbone were inactive in this transformation as they tend to form inactive palladium-bis-ligand complexes. SPO,P ligands however, were able to promote the desired reaction in a highly selective fashion although only low activities were found. During this work as well a new organo-catalyst, based on the structure of 2,3-dihydrobenzo[1,4]oxazine, was developed which allows for the asymmetric organo-catalyzed transfer-hydrogenation of α,β-unsaturated aldehydes. This catalyst was able to reduce for the first time β, β-diaryl acrylaldehydes with very good activities and high enantioselectivities. Moreover an ESI-MS based mechanistic study on the tripeptide catalyzed conjugate addition reaction of aldehydes to nitroolefins was carried out. By this all reaction intermediates postulated for an enamine mechanism have been detected. Furthermore the attack of the enamine onto the nitroolefin was found to be the selectivity determining step in this process. The last part of this work aimed for the asymmetric α -allylation of carbonyl compounds by a tandem-catalysis approach. An intensive screening of both the organo-catalyst and the palladium-ligand led to reaction conditions which allowed for the selective mono-allylation of ketones in high yields. The formation of a quaternary center by α -allylation of α -branched aldehydes was also achieved. However, only low enantiomeric excesses were obtained in this transformation for the different catalyst systems tested.

Download or read book Enantioselective C C Bond Forming Reactions written by and published by Elsevier. This book was released on 2023-12-01 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: Enantioselective C-C Bond Forming Reactions: From Metal Complex-, Organo-, and Bio-catalyzed Perspectives, Volume 73 in the Advances in Catalysis series, highlights new advances in the field, with this new volume presenting interesting chapters on topics such as An introduction to Chirality, Metal-catalyzed stereoselective C-C-bond forming reactions, Enantioselective C-C bond forming reactions promoted by organocatalysts based on unnatural amino acid derivatives, Enantioselective C-C bond formation in complex multicatalytic system, Gold-based multicatalytic systems for enantioselective C-C Bond forming reactions, Novel enzymatic tools for C-C bond formation through the development of new-to-nature biocatalysis, and more. Provides the authority and expertise of leading contributors from an international board of authors Presents the latest release in Advances in Catalysis serials Updated release includes the latest information in the field

Download or read book Chiral Diazaligands for Asymmetric Synthesis written by Marc Lemaire and published by Springer. This book was released on 2010-02-12 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of phosphine derivatives has historically induced the tremendous development of catalysis (both non-asymmetric and asymmetric). Although the chemistry of amines is more documented, the use of nitrogen-containing ligands only appeared recently. Nevertheless, during the last ten years, the results describing chiral diamine preparations and their uses in asymmetric catalysis and synthesis are increasing faster than their phosphorus counterparts. The reader will find in this volume the most recent methods for the synthesis of chiral diamines as well as their applications in asymmetric catalysis of CC bond formation. Particular attention will be given to spartein and derivatives of such diamines. Recently, the particular properties and the chemistry of amines allowed to obtain catalysts easy to separate and recycle and new types of ligands such as diaminocarbenes, ureas and thioureas. Finally, the complexing properties of some diamines allowed the formation of complexes with chirality "at the metal " which is of major theoretical interest and presents numerous potential applications.

Download or read book Reagents Auxiliaries and Catalysts for C C Bond Formation written by Robert M. Coates and published by John Wiley & Sons. This book was released on 1999-07-09 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Reagents for Organic Synthesis Reagents, Auxiliaries and Catalysts for C-C Bond Formation Robert M. Coates and Scott E. Denmark The University of Illinois, Urbana, USA Recognising the critical need for bringing a handy reference work that deals with the most popular reagents in synthesis to the laboratory of practising organic chemists, the Editors, of the acclaimed Encyclopedia of Reagents for Organic Synthesis (EROS) have selected the most important and useful reagents employed in contemporary organic synthesis. The Handbook of Reagents for Organic Synthesis; Reagents Auxiliaries and Catalysts for C-C Bond Formation, provides practical and concise information on a diverse group of reagents. To familiarise the user with the spectrum of reagents contained within this volume, the editors have subdivided more than 200 entries into 22 classes based on their chemical structures and function. The articles, arranged alphabetically, contain all of the information found in EROS as well as expanded reagents listings. In addition, new listings of recently published review articles and monographs are included, as well as relevant Organic Syntheses procedures that deal with either the preparations or reactions of the featured reagents. This comprehensive and well referenced handbook will prove of great value to all practitioners in the field of organic chemistry.

Download or read book Synthesis and Use of C2 symmetric Chiral Phenols for Asymmetric C C Bond Formation Using Organozinc Reagents written by Lai Chu Lin and published by . This book was released on 2002 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Several C2-symmetric chiral phenols were synthesized from derivatives of natural products (1R,2S)-ephedrine, (1S,2S)-pseudoephedrine and (L)-proline. The use of these ligands for asymmetric alkylation of benzaldehyde, Cu-catalyzed and Ni-catalyzed conjugate addition to chalcone using diethylzinc were explored. Moderate enantiomeric excess of 37% was obtained in the alkylation of benzaldehyde, whereas 60% ee and ̃40% ee were obtained for the Ni-catalyzed and Cu-catalyzed conjugate addition to chalcone, respectively, with moderate yields in all cases. Although these ligands were shown not be very efficient chiral catalysts for these types of reactions, they provided some structural information for future improvement on design of chiral auxiliaries for asymmetric induction.

Download or read book Privileged Chiral Ligands and Catalysts written by Qi-Lin Zhou and published by John Wiley & Sons. This book was released on 2011-02-10 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt: Catalytic asymmetric synthesis has been one of the most active research areas in chemistry (Nobel Prize in 2001). The development of efficient chiral catalysts plays a crucial role in asymmetric catalysis. Although many chiral ligands/catalysts have been developed in the past decades, the most efficient catalysts are derived from a few core structures, called "privileged chiral catalysts". This ultimate "must have" and long awaited reference for every chemist working in the field of asymmetric catalysis starts with the core structure of the catalysts, explaining why a certain ligand or catalyst is so successful. It describes in detail the history, the basic structural characteristics, and the applications of these "privileged catalysts". This novel presentation provides readers with a much deeper insight into the topic and makes it a must-have for organic chemists, catalytic chemists, chemists working with/on organometallics, chemists in industry, and libraries. From the contents: * BINAP * Bisphosphacycles - From DuPhos and BPE to a Diverse Set of Broadly Applied Ligands * Josiphos Ligands: From Discovery to Technical Applications * Chiral Spiro Ligands * Chiral Bisoxazoline Ligands * PHOX Ligands * Chiral Salen Complexes * BINOL * TADDOLate Ligands * Cinchona Alkaloids * Proline Derivatives

Download or read book Fundamentals of Asymmetric Catalysis written by Patrick J. Walsh and published by University Science Books. This book was released on 2009-01-02 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work describes the essential aspects of enantioselective catalysis, with chapters organised by concept rather than by reaction type. Each concept is supported by examples to give the reader broad exposure to a wide range of catalysts, reactions and reaction mechanisms.

Download or read book Stereoselective Organocatalysis written by Ramon Rios Torres and published by John Wiley & Sons. This book was released on 2013-04-29 with total page 581 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sets forth an important group of environmentally friendly organic reactions With contributions from leading international experts in organic synthesis, this book presents all the most important methodologies for stereoselective organocatalysis, fully examining both the activation mode as well as the type of bond formed. Clear explanations guide researchers through all the most important methods used to form key chemical bonds, including carbon-carbon (C–C), carbon-nitrogen (C–N), and carbon-halogen (C–X) bonds. Moreover, readers will discover how the use of non-metallic catalysts facilitates a broad range of important reactions that are environmentally friendly and fully meet the standards of green chemistry. Stereoselective Organocatalysis begins with an historical overview and a review of activation modes in asymmetric organocatalysis. The next group of chapters is organized by bond type, making it easy to find bonds according to their applications. The first of these chapters takes a detailed look at the many routes to C–C bond formation. Next, the book covers: Organocatalytic C–N bond formation C–O bond formation C–X bond formation C–S, C–Se, and C–B bond formation Enantioselective organocatalytic reductions Cascade reactions forming both C–C bonds and C–heteroatom bonds The final chapter is devoted to the use of organocatalysis for the synthesis of natural products. All the chapters in the book are extensively referenced, serving as a gateway to the growing body of original research reports and reviews in the field. Based on the most recent findings and practices in organic synthesis, Stereoselective Organocatalysis equips synthetic chemists with a group of organocatalytic reactions that will help them design green reactions and overcome many challenges in organic synthesis.

Download or read book Asymmetric Catalysis of Carbon carbon Bond Forming Reactions written by Souvagya Biswas and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Nature has established numerous methods for synthesis of complex molecules utilizing simple and abundant resources such as the use of CO2, H2O and N2 using sunlight as a source of energy. Even more impressive are the high chemo-, regio-, and stereoselectivites observed in these transformations with a wide variety of both prochiral and chiral substrates. However, methods for the enantioselective incorporation of feedstock materials such as CO, HCN, CO2 or simple alkenes into prochiral molecules are limited and remain an important challenge in the field. The hydrovinylation reaction (HV), where ethylene is added across a carbon-carbon double bond, has been known for nearly fifty years, starting with the works of Hata, Alderson and Wilke. During the past few years, through an approach that relied mostly on mechanistic insights and systematic examination of ligand effects, our group discovered a number of protocols for Ni(II)- and Co(II)-catalyzed enantioselective hydrovinylation (HV) reactions of vinylarenes, 1,3-dienes and strained olefins. While the Ni(II)-catalyzed hydrovinylation (HV) reaction is one of the most selective asymmetric catalyzed carbon-carbon bond forming reactions, its use has been limited to alkenes conjugated to an aromatic ring and strained alkenes. We recently found Co(II)-bisphosphine complexes show much improved regioselectivity with broader functional group compatibility in 1,3-dienes. By utilizing finely tuned catalysts derived from Co(II)-bisphosphine complexes and Me3Al or methylaluminoxane (MAO) acyclic (E) and (Z)-1,3-dienes were found to undergo efficient hydrovinylation giving mostly 1,4-hydrovinylation products in an atmosphere of ethylene. In order to expand the hydrovinylation chemistry, we turned our attention to one of the mostly widely used intermediates on organic chemistry, viz., silyl enol ethers. Trialkylsilyl enol ethers are exceptionally versatile intermediates often used as enolate surrogates for the synthesis of carbonyl compounds. Yet there are no reports of broadly applicable, catalytic methods for the synthesis of chiral silyl enol ethers carrying latent functionalities useful for synthetic operations beyond the many possible reactions of the enol ether moiety itself. The work presented herein reports a general procedure for highly catalytic (substrate : catalyst ratio up to 1000:1) and enantioselective (96% to 98% major enantiomer) synthesis of silyl enol ethers bearing a vinyl group at a chiral carbon at the beta-position. The reactions, run under ambient conditions, use trialkylsiloxy-1,3-dienes and ethylene (1 atmosphere) as precursors, and readily available (bis-phosphine)-cobalt(II) complexes as catalysts. Once we have established the HV reaction conditions of the siloxydienes, we turn our attention towards diastereoselective functionalization of the hydrovinylated products. Under optimized conditions, we are able to successfully utilize our 1,4-hydrovinylated products as reactive nucleophilic synthons for several electrophilic reactions keeping moderate to good diastereomeric ratios. The silyl enolates can be readily converted into novel enantiopure vinyl triflates, a class of highly versatile cross-coupling reagents, enabling the syntheses of other enantiomerically pure trisubstituted alkene intermediates not easily accessible by current methods.

Download or read book Chiral Ligands written by Montserrat Diéguez and published by CRC Press. This book was released on 2021-05-13 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many new drugs on the market are chiral compounds, that is, they can exist in two non-superimposable mirror-image forms. Asymmetric catalysis encompasses a large variety of processes for obtaining such compounds. The performance of the catalyst in those processes largely depends on the ligand that makes up the catalyst. This book describes the most relevant ligand libraries for some key processes, including an overview of the state of art and the key mechanistic aspects that favor a high catalytic performance. Key Features: The book presents historical content from the time of discovery for each family of ligands. Provides a description of the synthetic route and the ligand library's application in various catalytic asymmetric reactions Suitable as supplementary reading for courses targeting the design, synthesis and application of chiral catalysts, asymmetric catalysis and sustainable production Edited by a distinguished scientist in the field, the book has a diverse audience including research groups in homogeneous catalysis, particularly asymmetric transformations

Download or read book C H Activation for Asymmetric Synthesis written by Françoise Colobert and published by John Wiley & Sons. This book was released on 2019-11-11 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides, in one handbook, comprehensive coverage of one of the hottest topics in stereoselective chemistry Written by leading international authors in the field, this book introduces readers to C-H activation in asymmetric synthesis along with all of its facets. It presents stereoselective C-H functionalization with a broad coverage, from outer-sphere to inner-sphere C-H bond activation, and from the control of olefin geometry to the induction of point, planar and axial chirality. Moreover, methods wherein asymmetry is introduced either during the C-H activation or in a different elementary step are discussed. Presented in two parts?asymmetric activation of C(sp3)-H bonds and stereoselective synthesis implying activation of C(sp2)-H bonds?CH-Activation for Asymmetric Synthesis showcases the diversity of stereogenic elements, which can now be constructed by C-H activation methods. Chapters in Part 1 cover: C(sp3)-H bond insertion by metal carbenoids and nitrenoids; stereoselective C-C bond and C-N bond forming reactions through C(sp3)?H bond insertion of metal nitrenoids; enantioselective intra- and intermolecular couplings; and more. Part 2 looks at: C-H activation involved in stereodiscriminant step; planar chirality; diastereoselective formation of alkenes through C(sp2)?H bond activation; amongst other methods. -Covers one of the most rapidly developing fields in organic synthesis and catalysis -Clearly structured in two parts (activation of sp3- and activation of sp2-H bonds) -Edited by two leading experts in C-H activation in asymmetric synthesis CH-Activation for Asymmetric Synthesis will be of high interest to chemists in academia, as well as those in the pharmaceutical and agrochemical industry.

Download or read book Supramolecular Catalysis written by Piet W.N.M. van Leeuwen and published by John Wiley & Sons. This book was released on 2021-12-31 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supramolecular Catalysis Provides a timely and detailed overview of the expanding field of supramolecular catalysis The subdiscpline of supramolecular catalysis has expanded in recent years, benefiting from the development of homogeneous catalysis and supramolecular chemistry. Supramolecular catalysis allows chemists to design custom-tailored metal and organic catalysts by devising non-covalent interactions between the various components of the reaction. Edited by two world-renowned researchers, Supramolecular Catalysis: New Directions and Developments summarizes the most significant developments in the dynamic, interdisciplinary field. Contributions from an international panel of more than forty experts address a broad range of topics covering both organic and metal catalysts, including emergent catalysis by self-replicating molecules, switchable catalysis using allosteric effects, supramolecular helical catalysts, and transition metal catalysis in confined spaces. This authoritative and up-to-date volume: Covers ligand-ligand interactions, assembled multi-component catalysts, ligand-substrate interactions, and supramolecular organocatalysis and non-classical interactions Presents recent work on supramolecular catalysis in water, supramolecular allosteric catalysis, and catalysis promoted by discrete cages, capsules, and other confined environments Highlights current research trends and discusses the future of supramolecular catalysis Includes full references and numerous figures, tables, and color illustrations Supramolecular Catalysis: New Directions and Developments is essential reading for catalytic chemists, complex chemists, biochemists, polymer chemists, spectroscopists, and chemists working with organometallics.

Download or read book Principles of Asymmetric Synthesis written by R.E. Gawley and published by Elsevier. This book was released on 1996-11-21 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt: The world is chiral. Most of the molecules in it are chiral, and asymmetric synthesis is an important means by which enantiopure chiral molecules may be obtained for study and sale. Using examples from the literature of asymmetric synthesis (more than 1300 references), the aim of this book is to present a detailed analysis of the factors that govern stereoselectivity in organic reactions. It is important to note that the references were each individually checked by the authors to verify relevance to the topics under discussion. The study of stereoselectivity has evolved from issues of diastereoselectivity, through auxiliary-based methods for the synthesis of enantiomerically pure compounds (diastereoselectivity followed by separation and auxiliary cleavage), to asymmetric catalysis. In the latter instance, enantiomers (not diastereomers) are the products, and highly selective reactions and modern purification techniques allow preparation - in a single step - of chiral substances in 99% ee for many reaction types. After an explanation of the basic physical-organic principles of stereoselectivity, the authors provide a detailed, annotated glossary of stereochemical terms. A chapter on "Analytical Methods" provides a critical overview of the most common methods for analysis of stereoisomers. The authors then follow the 'tried-and-true' format of grouping the material by reaction type. Thus, there are four chapters on carbon-carbon bond forming reactions (enolate alkylations, organometal additions to carbonyls, aldol and Michael reactions, and cycloadditions and rearrangements), one chapter on reductions and hydroborations (carbon-hydrogen bond forming reactions), and one on oxidations (carbon-oxygen and carbon-nitrogen bond forming reactions). Leading references are provided to natural product synthesis that have been accomplished using a given reaction as a key step. In addition to tables of examples that show high selectivity, a transition state analysis is presented to explain - to the current level of understanding - the stereoselectivity of each reaction. In one case (Cram's rule) the evolution of the current theory is detailed from its first tentative (1952) postulate to the current Felkin-Anh-Heathcock formalism. For other reactions, only the currently accepted rationale is presented. Examination of these rationales also exposes the weaknesses of current theories, in that they cannot always explain the experimental observations. These shortcomings provide a challenge for future mechanistic investigations.

Download or read book Asymmetric C C Bond Formation written by Mushtaq Mulla and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: