Asymmetric Synthesis Ii

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 Synthesis II written by Mathias Christmann and published by John Wiley & Sons. This book was released on 2013-03-19 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: After the overwhelming success of Asymmetric Synthesis - The Essentials, displaying a broad range of organic asymmetric syntheses, this is the second edition with latest subjects and authors. While the aim of the first edition was mainly to honor the achievements of the pioneers in asymmetric syntheses, the aim of this new edition was bringing the current developments, especially from younger colleagues, to the attention of students. The format of the book remained unchanged, i.e. short conceptual overviews by young leaders in their field including a short biography of the authors. The growing multidisciplinary research within chemistry is reflected in the selection of topics including metal catalysis, organocatalysis, physical organic chemistry, analytical chemistry, and its applications in total synthesis, materials research and industry. The prospective reader of this book is a graduate or undergraduate student of advanced organic chemistry as well as the industrial chemist who wants to get a brief update on the current developments in the field.

Download or read book Asymmetric Synthesis written by Garry Procter and published by Oxford University Press on Demand. This book was released on 1996 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers a wide range of reactions which are of importance in the asymmetric synthesis of organic compounds. The principles of asymmetric additions to carbonyls, enolate alkylation, aldol reactions, additions to C-C double bonds, reduction and oxidation, rearrangements, and hydrolysis/ esterification reactions are covered, and selected examples used to illustrated the various topics. Numerous references to original literature should be of ues to organic chemists interested in the area of asymmetric synthesis.

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.

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 Catalysis in Asymmetric Synthesis written by Vittorio Caprio and published by John Wiley & Sons. This book was released on 2009-03-09 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: Asymmetric synthesis has become a major aspect of modern organic chemistry. The stereochemical properties of an organic compound are often essential to its bioactivity, and the need for stereochemically pure pharmaceutical products is a key example of the importance of stereochemical control in organic synthesis. However, achieving high levels of stereoselectivity in the synthesis of complex natural products represents a considerable intellectual and practical challenge for chemists. Written from a synthetic organic chemistry perspective, this text provides a practical overview of the field, illustrating a wide range of transformations that can be achieved. The book captures the latest advances in asymmetric catalysis with emphasis placed on non-enzymatic methods. Topics covered include: Reduction of alkenes, ketones and imines Nucleophilic addition to carbonyl compounds Catalytic carbon-carbon bond forming reactions Catalytic reactions involving metal carbenoids Conjugate addition reactions Catalysis in Asymmetric Synthesis bridges the gap between undergraduate and advanced level textbooks and provides a convenient point of entry to the primary literature for the experienced synthetic organic chemist.

Download or read book The Chiral Carbon Pool and Chiral Sulfur, Nitrogen, Phosphorus, and Silicon Centers written by James D. Morrison and published by . This book was released on 1984 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Asymmetric Synthesis, Volume 4: The Chiral Carbon Pool and Chiral Sulfur, Nitrogen, Phosphorus, and Silicon Centers describes the practical methods of obtaining chiral fragments. Divided into five chapters, this book specifically examines initial chiral transmission and extension. The opening chapter describes the so-called chiral carbon pool, the readily available chiral carbon fragments used as building blocks in synthesis. This chapter also provides a list of 375 chiral building blocks, along with their commercial sources, approximate prices, and methods of synthesis. Schemes involving almo ...