Asymmetric Synthesis of Chiral Bipyridine-based Ligands for Use in Asymmetric Catalysis

Download Asymmetric Synthesis of Chiral Bipyridine-based Ligands for Use in Asymmetric Catalysis PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 260 pages
Book Rating : 4.:/5 (388 download)

DOWNLOAD NOW!


Book Synopsis Asymmetric Synthesis of Chiral Bipyridine-based Ligands for Use in Asymmetric Catalysis by : David A. Regan

Download or read book Asymmetric Synthesis of Chiral Bipyridine-based Ligands for Use in Asymmetric Catalysis written by David A. Regan and published by . This book was released on 2008 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Design, Synthesis and Evaluation of Chiral Nonracemic Ligands and Catalysts for Asymmetric Synthesis

Download Design, Synthesis and Evaluation of Chiral Nonracemic Ligands and Catalysts for Asymmetric Synthesis PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (755 download)

DOWNLOAD NOW!


Book Synopsis Design, Synthesis and Evaluation of Chiral Nonracemic Ligands and Catalysts for Asymmetric Synthesis by : Michael P. A. Lyle

Download or read book Design, Synthesis and Evaluation of Chiral Nonracemic Ligands and Catalysts for Asymmetric Synthesis written by Michael P. A. Lyle and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work described in this thesis concerns the design, synthesis and evaluation of new chiral nonracemic ligands and catalysts for use in asymmetric reactions. A series of chiral nonracemic chloroacetals were prepared from 2-chloro-4- methyl-6,7-dihydro-5H-[l]pyrindine-7-one and a variety of C2-symmetric and chiral nonracemic 1,2-ethanediols (R = Me, i-Pr and Ph). These chloroacetals were further elaborated, in a modular fashion, to provide a series of chiral ligands and catalysts. A new class of C2-symmetric 2,2'-bipyridyl ligands were prepared in one step fiom the chloroacetals via a nickel(0)-mediated homo-coupling reaction. These ligands were then evaluated as chiral directors in copper@)-catalyzed asymmetric cyclopropanation reactions of styrene and diazoesters (up to 44% ee). A chiral pyridine N-oxide and a C2-symmetric 2,2'-bipyridyl N, N'-dioxide were also prepared by direct oxidation of the corresponding pyridine and the 2,2'-bipyridine, respectively. These chiral N-oxides were evaluated as chiral catalysts in desymmeterization reactions of cis-stilbene oxide (up to 20% ee). A series of pyridylphosphine ligands (P, N-ligands) were subsequently prepared in two steps from the chloroacetals via a Suzuki coupling reaction with orthofluorophenylboronic and on subsequent displacement of the fluoride with the potassium anion of diphenylphosphine. These ligands were then evaluated in palladium-catalyzed asymmetric allylic substitution reactions of racemic 3-acetoxy-l,3-diphenyl-1-propene with dimethyl malonate. Optimization of the reaction conditions resulted in the formation of the alkylated product in excellent yield (91%) and in high enantiomeric excess (90%). A related chiral nonracemic and C2-symmetric 2,2'-bipyridyl ligand was prepared from 2-chloro-4-methyl-5H-[llpyrindine. This pyrindine was prepared from a common intermediate that was used in the synthesis of the first generation of ligands. The chirality of this second generation ligand was installed by a Sharpless asymmetric dihydroxylation reaction (90% ee). The subsequently elaborated 2,2'-bipyridyl ligand (enriched to>99% ee) was then evaluated in copper(1)-catalyzed asymmetric cyclopropanation reactions of alkenes and diazoesters. In the case of the reaction of para-fluorostyrene and tert-butyl diazoacetate, the corresponding cyclopropane was formed in good diastereoselectivity (92:8) and in excellent enantioselectivity (99% ee). This ligand was also evaluated in copper(I1)-catalyzed asymmetric Friedel-Crafts alkylation reactions of various substituted indoles (up to 90% ee) and in copper(1)- catalyzed asymmetric allylic oxidation reactions of cyclic alkenes with tert-butyl peroxybenzoate (up to 9 1 % ee).

Chiral Diazaligands for Asymmetric Synthesis

Download Chiral Diazaligands for Asymmetric Synthesis PDF Online Free

Author :
Publisher : Springer
ISBN 13 : 9783642065385
Total Pages : 0 pages
Book Rating : 4.0/5 (653 download)

DOWNLOAD NOW!


Book Synopsis Chiral Diazaligands for Asymmetric Synthesis by : Marc Lemaire

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.

Chiral Sulfur Ligands

Download Chiral Sulfur Ligands PDF Online Free

Author :
Publisher : Royal Society of Chemistry
ISBN 13 : 1847559247
Total Pages : 403 pages
Book Rating : 4.8/5 (475 download)

DOWNLOAD NOW!


Book Synopsis Chiral Sulfur Ligands by : Hélène Pellissier

Download or read book Chiral Sulfur Ligands written by Hélène Pellissier and published by Royal Society of Chemistry. This book was released on 2009 with total page 403 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this book is to show the high potential of chiral sulfur-containing ligands to promote numerous asymmetric catalytic transformations. These ligands can now be recognised as real competitors to the more usual phosphorus- or nitrogen-containing ligands.

Chiral Ligands

Download Chiral Ligands PDF Online Free

Author :
Publisher : CRC Press
ISBN 13 : 1000379000
Total Pages : 298 pages
Book Rating : 4.0/5 (3 download)

DOWNLOAD NOW!


Book Synopsis Chiral Ligands by : Montserrat Diéguez

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

Privileged Chiral Ligands and Catalysts

Download Privileged Chiral Ligands and Catalysts PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 3527635211
Total Pages : 670 pages
Book Rating : 4.5/5 (276 download)

DOWNLOAD NOW!


Book Synopsis Privileged Chiral Ligands and Catalysts by : Qi-Lin Zhou

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

Chiral Ferrocenes in Asymmetric Catalysis

Download Chiral Ferrocenes in Asymmetric Catalysis PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 3527322809
Total Pages : 433 pages
Book Rating : 4.5/5 (273 download)

DOWNLOAD NOW!


Book Synopsis Chiral Ferrocenes in Asymmetric Catalysis by : Li-Xin Dai

Download or read book Chiral Ferrocenes in Asymmetric Catalysis written by Li-Xin Dai and published by John Wiley & Sons. This book was released on 2010-02-01 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book meets the long-felt need for a reference on ferrocenes with the focus on catalysis. It provides a thorough overview of the synthesis and characterization of different types of chiral ferrocene ligands, their application to various catalytic asymmetric reactions, and versatile chiral materials as well as drug intermediates synthesized from them. Written by the "who's who" of ferrocene catalysis, this is a guide to the design of new ferrocene ligands and synthesis of chiral synthetic intermediates, and will thus be useful for organic, catalytic and synthetic chemists working in academia, industrial research or process development.

Principles and Applications of Asymmetric Synthesis

Download Principles and Applications of Asymmetric Synthesis PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 0471465240
Total Pages : 536 pages
Book Rating : 4.4/5 (714 download)

DOWNLOAD NOW!


Book Synopsis Principles and Applications of Asymmetric Synthesis by : Guo-Qiang Lin

Download or read book Principles and Applications of Asymmetric Synthesis written by Guo-Qiang Lin and published by John Wiley & Sons. This book was released on 2003-05-29 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt: Asymmetric synthesis remains a challenge to practicing scientistsas the need for enantiomerically pure or enriched compoundscontinues to increase. Over the last decade, a large amount ofliterature has been published in this field. Principles andApplications of Asymmetric Synthesis consolidates and evaluates themost useful methodologies into a one-volume resource for theconvenience of practicing scientists and students. Authored by internationally renowned scientists in the field, thisreliable reference covers more than 450 reactions and includesimportant stoichiometric as well as catalytic asymmetric reactions.The first chapter reviews the basic principles, commonnomenclature, and analytical methods, and the remainder of the bookis organized according to reaction type. The text examines suchtopics as: Carbon-carbon bond formations involving carbonyls, enamines,imines, and enolates Asymmetric C-O bond formations including epoxidation,dihydroxylation, and aminohydroxylation Asymmetric synthesis using the Diels-Alder reaction and othercyclizations Applications to the total synthesis of natural products Use of enzymes in asymmetric synthesis Practicing chemists in the pharmaceutical, fine chemical, andagricultural professions as well as graduate students will findthat Principles and Applications of Asymmetric Synthesis affordscomprehensive and current coverage.

Axially Chiral Compounds

Download Axially Chiral Compounds PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 3527347127
Total Pages : 338 pages
Book Rating : 4.5/5 (273 download)

DOWNLOAD NOW!


Book Synopsis Axially Chiral Compounds by : Bin Tan

Download or read book Axially Chiral Compounds written by Bin Tan and published by John Wiley & Sons. This book was released on 2021-11-22 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: Axially Chiral Compounds Explore this comprehensive and current volume summarizing the characteristics, synthesis, and applications of axial chirality Appearing widely in natural products, biologically active molecules, asymmetric chemistry, and material science, axially chiral motifs constitute the core backbones of the majority of chiral ligands and organocatalysts in asymmetric catalysis. In a new work of particular relevance to synthetic chemists, Axially Chiral Compounds: Asymmetric Synthesis and Applications delivers a clearly structured and authoritative volume covering the classification, characteristics, synthesis, and applications of axial chirality. A must read for every synthetic chemist practicing today, the book follows the development history, research status, and applications of axial chirality. An introductory chapter familiarizes the reader with foundational material before the distinguished authors describe the different classes and the synthesis of axial chiral compounds used in asymmetric synthesis. The book concludes with a focus on the applications of chiral ligands, chiral catalysts, and materials. Readers will also benefit from the inclusion of: A thorough introduction to asymmetric synthesis, including biaryls atropisomers, heterobiaryls atropisomers, and non-biaryls atropisomers Explorations of chiral allene, spiro skeletons, and natural products Practical discussions of asymmetric transformation, chiral ligands, and chiral catalysts An examination of miscellaneous applications of axially chiral compounds Perfect for organic chemists, chemists working with or on organometallics, catalytic chemists, and materials scientists, Axially Chiral Compounds: Asymmetric Synthesis and Applications will also earn a place in the libraries of natural products chemists who seek a one-stop reference for compounds exhibiting axial chirality.

Synthesis and Purification of Chiral Ligands for Use in Asymmetric Catalysis

Download Synthesis and Purification of Chiral Ligands for Use in Asymmetric Catalysis PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 150 pages
Book Rating : 4.:/5 (164 download)

DOWNLOAD NOW!


Book Synopsis Synthesis and Purification of Chiral Ligands for Use in Asymmetric Catalysis by : Alexander V. Rupert

Download or read book Synthesis and Purification of Chiral Ligands for Use in Asymmetric Catalysis written by Alexander V. Rupert and published by . This book was released on 2007 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Catalytic Asymmetric Synthesis

Download Catalytic Asymmetric Synthesis PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 047122054X
Total Pages : 879 pages
Book Rating : 4.4/5 (712 download)

DOWNLOAD NOW!


Book Synopsis Catalytic Asymmetric Synthesis by : Iwao Ojima

Download or read book Catalytic Asymmetric Synthesis written by Iwao Ojima and published by John Wiley & Sons. This book was released on 2004-08-27 with total page 879 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the reviews of the First Edition . . . "An excellent text . . . will no doubt provide the benchmark for comparative works for many years."-Journal of the American Chemical Society "A resounding success . . . the definitive current summaries on their respective subjects."-Synthesis Since this important work was first published in 1993, the field of catalytic asymmetric synthesis has grown explosively, spawning effective new methods for obtaining enantiomerically pure compounds on a large scale and stimulating new applications in diverse fields-from medicine to materials science. Catalytic Asymmetric Synthesis, Second Edition addresses these rapid changes through new or substantially revised contributions from highly recognized world leaders in the field. It presents detailed accounts of the most important catalytic asymmetric reactions known today, discusses recent advances, and retains from the previous edition essential and intriguing information on the initial development of certain processes. An excellent working resource for academic researchers and industrial chemists alike, the Second Edition features: * Contributions from Noyori, Sharpless, Kagan, Trost, Overman, Shibasaki, Doyle, Okamoto, Bolm, Carreira, and many other internationally renowned authorities * New chapters on asymmetric carbometallations, asymmetric amplification and autocatalysis, and asymmetric polymerization * Extended coverage of asymmetric carbene reactions, including asymmetric intramolecular carbene insertion to C-H bonds as well as asymmetric dihydroxylation and aminohydroxylation * Extended coverage of asymmetric carbon-carbon bond-forming reactions and applications * An appendix listing all chiral ligands in the book

Handbook of Chiral Chemicals

Download Handbook of Chiral Chemicals PDF Online Free

Author :
Publisher : CRC Press
ISBN 13 : 1420027301
Total Pages : 632 pages
Book Rating : 4.4/5 (2 download)

DOWNLOAD NOW!


Book Synopsis Handbook of Chiral Chemicals by : David Ager

Download or read book Handbook of Chiral Chemicals written by David Ager and published by CRC Press. This book was released on 2005-10-21 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: As pharmaceutical companies look to develop single enantiomers as drug candidates, chemists are increasingly faced with the problems associated with this subclass of organic synthesis. "The Handbook of Chiral Chemicals, Second Edition" highlights the problems associated with the production of chiral compounds on a commercial scale. The handbook fir

Asymmetric Synthesis of Three-Membered Rings

Download Asymmetric Synthesis of Three-Membered Rings PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 3527802037
Total Pages : 800 pages
Book Rating : 4.5/5 (278 download)

DOWNLOAD NOW!


Book Synopsis Asymmetric Synthesis of Three-Membered Rings by : Hélène Pellissier

Download or read book Asymmetric Synthesis of Three-Membered Rings written by Hélène Pellissier and published by John Wiley & Sons. This book was released on 2017-03-28 with total page 800 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first handbook to focus on the asymmetric synthesis of different types of three-membered rings. The outstanding and experienced authors have an excellent international reputation and cover cyclopropanes, epoxides and aziridines as well as chiral oxaziridines in equal measure. To this end, they describe in detail different synthetic approaches starting with chiral substrates as well as the application of chiral metal- or organocatalysts. Furthermore, methods for the kinetic resolution of initially racemic products are treated alongside recent advances and novel developments in established techniques for the synthesis of three-membered rings. With its structured composition this is of high interest to scientists in methodological and natural product synthesis as well as those in industrial and pharmaceutical chemistry.

Chiral Auxiliaries and Ligands in Asymmetric Synthesis

Download Chiral Auxiliaries and Ligands in Asymmetric Synthesis PDF Online Free

Author :
Publisher : Wiley-Interscience
ISBN 13 :
Total Pages : 744 pages
Book Rating : 4.3/5 (91 download)

DOWNLOAD NOW!


Book Synopsis Chiral Auxiliaries and Ligands in Asymmetric Synthesis by : J. Seyden-Penne

Download or read book Chiral Auxiliaries and Ligands in Asymmetric Synthesis written by J. Seyden-Penne and published by Wiley-Interscience. This book was released on 1995-10-23 with total page 744 pages. Available in PDF, EPUB and Kindle. Book excerpt: Table of Contents Preface Abbreviations Introduction 1 1 Enantiomerically Pure Chiral Auxiliaries 43 2 Chiral Reagents 87 3 Chiral Catalysis and Catalysts Bearing Chiral Ligands 117 4 Asymmetric Deprotonations and Protonations 143 5 Alkylations and Related Reactions 157 6 Additions to C=O and C=N Double Bonds 209 7 Additions to Carbon-Carbon Double Bonds 367 8 Additions to Double Bonds Bearing Heteroatoms. Oxidations of Sulfides and Selenides 503 9 Cycloadditions 513 10 Sigmatropic Rearrangements 593 11 Transition Metal Catalyzed Reactions 619 References 637 Index 707.

Nickel-catalyzed Asymmetric Cross-couplings of Secondary Allylic Chlorides and Planar-chiral Compounds in Asymmetric Synthesis

Download Nickel-catalyzed Asymmetric Cross-couplings of Secondary Allylic Chlorides and Planar-chiral Compounds in Asymmetric Synthesis PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 185 pages
Book Rating : 4.:/5 (367 download)

DOWNLOAD NOW!


Book Synopsis Nickel-catalyzed Asymmetric Cross-couplings of Secondary Allylic Chlorides and Planar-chiral Compounds in Asymmetric Synthesis by : Sunghee Son

Download or read book Nickel-catalyzed Asymmetric Cross-couplings of Secondary Allylic Chlorides and Planar-chiral Compounds in Asymmetric Synthesis written by Sunghee Son and published by . This book was released on 2008 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Part I, nickel-catalyzed asymmetric carbon-carbon bond-forming reactions are described. A nickel/Pybox system effectively catalyzes regio- and enantioselective cross-couplings between racemic secondary allylic chlorides and readily available alkylzinc halides. This method is applied to generate two stereo centers in a formal total synthesis of fluvirucinine A1. In Part II, the use of planar-chiral compounds as ligands or catalysts in organic synthesis is described. A C2-symmetric planar-chiral bipyridine is an efficient ligand for copper-catalyzed asymmetric [4+1]-cycloadditions between enones and diazoacetates to form 2,3-dihydrofurans. The highly substituted dihydrofurans are not only obtained in good stereoselectivity but also readily converted to other useful molecules. This method is applied to the first catalytic enantioselective synthesis of a deoxy-C-nucleoside. The synthesis of new C2-symmetric planar-chiral catalysts is described. The diastereoslective functionalization of ferrocene using a chiral directing group enables the formation of a number of amines in enantiopure form. These catalysts are tested as several asymmetric catalysts.

Principles of Asymmetric Synthesis

Download Principles of Asymmetric Synthesis PDF Online Free

Author :
Publisher : Elsevier
ISBN 13 : 0080514774
Total Pages : 395 pages
Book Rating : 4.0/5 (85 download)

DOWNLOAD NOW!


Book Synopsis Principles of Asymmetric Synthesis by : R.E. Gawley

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.

Synthesis of Chiral Nonracemic C2-symmetric 2,2'-bipyridines and Their Evaluation as Ligands in Copper-catalyzed Asymmetric Reactions

Download Synthesis of Chiral Nonracemic C2-symmetric 2,2'-bipyridines and Their Evaluation as Ligands in Copper-catalyzed Asymmetric Reactions PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 528 pages
Book Rating : 4.:/5 (112 download)

DOWNLOAD NOW!


Book Synopsis Synthesis of Chiral Nonracemic C2-symmetric 2,2'-bipyridines and Their Evaluation as Ligands in Copper-catalyzed Asymmetric Reactions by : Brendan John Whelan

Download or read book Synthesis of Chiral Nonracemic C2-symmetric 2,2'-bipyridines and Their Evaluation as Ligands in Copper-catalyzed Asymmetric Reactions written by Brendan John Whelan and published by . This book was released on 2010 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis concerns the synthesis and evaluation of a series of new chiral nonracemic C2-symmetric 2,2'-bipyridines for use as ligands in catalytic asymmetric reactions. The 2,2'-bipyridines were prepared using a divergent synthetic strategy which employed an asymmetric dihydroxylation reaction of a 2-chloropyrindine as the key step. The resultant chiral diol was condensed with a series of symmetrical ketones to afford chiral acetals which were converted into the requisite ligand series. These ligands were evaluated in the asymmetric copper(I)-catalyzed cyclopropanation reaction of styrene and ethyldiazoacetate. The major Trans-cyclopropane products were isolated in good yield and very high enantioselectivities were achieved (up to 94% ee). These are amongst the highest enantioselectivities reported for chiral 2,2'-bipyridyl ligands. The most effective ligand, an adamantanone derivative, was evaluated in the copper(I)-catalyzed asymmetric allylic oxidation of cyclic alkenes with Tert-butyl peroxybenzoate. High enantioselectivities were also obtained in these reactions (up to 91% ee).