Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Extending Applications Of Magnesium Amide Bases In Asymmetric Synthesis And A Mild And Selective N Debenzylation Method
Download Extending Applications Of Magnesium Amide Bases In Asymmetric Synthesis And A Mild And Selective N Debenzylation Method full books in PDF, epub, and Kindle. Read online Extending Applications Of Magnesium Amide Bases In Asymmetric Synthesis And A Mild And Selective N Debenzylation Method ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Extending Applications of Magnesium Amide Bases in Asymmetric Synthesis and a Mild and Selective N-debenzylation Method by : Natalie R. Monks
Download or read book Extending Applications of Magnesium Amide Bases in Asymmetric Synthesis and a Mild and Selective N-debenzylation Method written by Natalie R. Monks and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Expansion of the application of readily available chiral magnesium-bisamides was the overall focus of the majority of this study. Comparing a structurally simple C2-symmetric magnesium bisamide and a chelating magnesium bisamide, a range of cyclobutanone substrates have been desymmetrised. Early studies employed the chlorotriethylsilane electrophile, however, efficiency of the processes with the chosen base system with cyclobutanone substrates was low. When the alternative electrophile, diphenylphosphoryl chloride, was utilised, however, a drastic improvement in both reactivity and selectivity was achieved. Optimisation of the reaction conditions with both a C2-symmetric magnesium bisamide and a chelating magnesium bisamide revealed selectivities of up to 99:1 er for the enantioenriched enol phosphate products. Furthermore, it was found that no additives are required within this novel base system and the deprotonation can be performed at a more elevated temperature of -40 °C whilst maintaining high selectivity. This efficient desymmetrisation was applied to a range of cyclobutanone substrates and seven novel enol phosphate products were formed in enantioselectivities between 76:24 and 99:1er, with the majority producing ratios greater than 89:11 er. Further application of a C2-symmetric magnesium bisamide was also sought by employing this base reagent within the synthetic route towards the natural product (+)-(S)-Sporochnol A. To this end, a scalable pathway towards a novel 4,4-disubstituted cyclohexanone was devised. The asymmetric deprotonation of this intermediate, utilising a C2-symmetric magnesium bisamide, subsequently embedded the all carbon quaternary stereocentre required within the natural product. Trapping the resulting chiral enolate with diphenylphosphoryl chloride furnished the desired enol phosphate in 88:12 er, which is an excellent level of enantioselectivity for a substrate of this type at a reaction temperature of -78 °C. Furthermore, the utility of the enol phosphate product was highlighted through a palladium-catalysed cross-coupling reaction with a Grignard reagent. Although completion of the synthesis of (+)-(S)-Sporochnol A was not achieved, the key asymmetric deprotonation and subsequent cross-coupling step were successful and high yielding. An additional study was the development of an improved method for the oxidation of secondary N-benzylamines. The application of DIAD as a means to oxidise secondary N-benzylamines, followed by a subsequent hydrolysis step has been employed to afford debenzylated free amines. This oxidation methodology has thus been applied to a range of amine substrates as an improved, mild, and selective method for benzyl deprotection. High yields of the free amines were obtained and the reaction proved to be tolerant of other functional groups and heteroatoms. Moreover, when an enantiopure secondary N-benzylamine was deprotected, the free primary amine remained optically pure, proving that these mild conditions do not interfere with other functionality within the molecule.
Book Synopsis The Development and Application of Magnesium Amide Bases in Asymmetric Synthesis by : Linsey S. Bennie
Download or read book The Development and Application of Magnesium Amide Bases in Asymmetric Synthesis written by Linsey S. Bennie and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A range of bridged bicyclic ketones were then prepared in order to probe their application in magnesium amide-mediated asymmetric deprotonation reactions. Initial studies were performed using a simple oxabicyclic substrate and our C2-symmetric bisamide. Pleasingly, after a short period of optimisation, the enantioenriched silyl enol ether was obtained in unprecedented yield and enantioselectivity. Attention was then turned to the analogous thiabicyclic ketone substrate. When performing the asymmetric deprotonation of this novel substrate under the previously optimised conditions at -78 oC, an outstanding level of enantioselection was observed (99:1 er), and the silyl enol ether product was obtained in good yield. Having achieved such impressive results at -78 oC, the efficiency of the transformation at room temperature was probed. Pleasingly, the enantioenriched silyl enol ether was obtained in excellent enantioselectivity (94:6 er) and yield, without the requirement for subambient temperatures. This is in marked contrast to the results achieved using the corresponding lithium amide, which delivered the silyl enol ether with a lower level of enantioselectivity (93:7) at -78 oC. Impressive results could also be achieved when the analogous alkylmagnesium amide was applied to the desymmetrisation of the thiabicyclic substrate. Studies within the area of magnesium base chemistry have been extended to the enantioselective total synthesis of the bicyclic eicosanoid, (-)-mucosin. The synthetic strategy which has been devised involves a magnesium base-mediated enantioselective deprotonation as the key transformation. As such, the required meso-ketone substrate has been prepared efficiently using a series of simple synthetic transformations. With the mesoketone in hand, conversion to the racemic enol silane has been achieved by utilising carboncentred magnesium base chemistry. In addition, preparation of the required allylic bromide electrophile has been completed in a short number of synthetic steps using readily available starting materials, and the racemic enol silane and allylic bromide coupling partners were reacted to give the required -substituted ketone in moderate yield. Efforts were then focused on the development of an asymmetric method for the preparation of the enol silane intermediate, delivering the optically-enriched enol silane in high enantioselectivity using our C2-symmetric magnesium bisamide (93:7 er) or the C2-symmetric lithium amide (94:6 er) at - 78 oC.
Book Synopsis Advances in Asymmetric Synthesis by :
Download or read book Advances in Asymmetric Synthesis written by and published by Elsevier. This book was released on 1995-03-01 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Asymmetric Synthesis
Book Synopsis Amide Bond Activation by : Michal Szostak
Download or read book Amide Bond Activation written by Michal Szostak and published by MDPI. This book was released on 2019-07-12 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: The amide bond represents a privileged motif in chemistry. The recent years have witnessed an explosion of interest in the development of new chemical transformations of amides. These developments cover an impressive range of catalytic N–C bond activation in electrophilic, Lewis acid, radical, and nucleophilic reaction pathways, among other transformations. Equally relevant are structural and theoretical studies that provide the basis for chemoselective manipulation of amidic resonance. This monograph on amide bonds offers a broad survey of recent advances in activation of amides and addresses various approaches in the field.
Book Synopsis Asymmetric Synthesis by : James D. Morrison
Download or read book Asymmetric Synthesis written by James D. Morrison and published by Elsevier. This book was released on 2012-12-02 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: The chapters in this volume have been written by some of the foremost practictioners in the field and should be of interest to both mechanistic and synthetic chemists.
Book Synopsis Side Reactions in Organic Synthesis by : Florencio Zaragoza Dörwald
Download or read book Side Reactions in Organic Synthesis written by Florencio Zaragoza Dörwald and published by John Wiley & Sons. This book was released on 2006-03-06 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most syntheses in the chemical research laboratory fail and usually require several attempts before proceeding satisfactorily. Failed syntheses are not only discouraging and frustrating, but also cost a lot of time and money. Many failures may, however, be avoided by understanding the structure-reactivity relationship of organic compounds. This textbook highlights the competing processes and limitations of the most important reactions used in organic synthesis. By allowing chemists to quickly recognize potential problems this book will help to improve their efficiency and success-rate. A must for every graduate student but also for every chemist in industry and academia. Contents: 1 Organic Synthesis: General Remarks 2 Stereoelectronic Effects and Reactivity 3 The Stability of Organic Compounds 4 Aliphatic Nucleophilic Substitutions: Problematic Electrophiles 5 The Alkylation of Carbanions 6 The Alkylation of Heteroatoms 7 The Acylation of Heteroatoms 8 Palladium-Catalyzed C-C Bond Formation 9 Cyclizations 10 Monofunctionalization of Symmetric Difunctional Substrates
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.
Book Synopsis Isocyanide-based Multicomponent Reactions by : Jonathan G. Rudick
Download or read book Isocyanide-based Multicomponent Reactions written by Jonathan G. Rudick and published by Frontiers Media SA. This book was released on 2020-02-20 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact.
Book Synopsis Greene's Protective Groups in Organic Synthesis by : Peter G. M. Wuts
Download or read book Greene's Protective Groups in Organic Synthesis written by Peter G. M. Wuts and published by John Wiley & Sons. This book was released on 2012-12-20 with total page 1108 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Fourth Edition of Greene's Protective Groups in Organic Synthesis continues to be an indispensable reference for controlling the reactivity of the most common functional groups during a synthetic sequence. This new edition incorporates the significant developments in the field since publication of the third edition in 1998, including... New protective groups such as the fluorous family and the uniquely removable 2-methoxybenzenesulfonyl group for the protection of amines New techniques for the formation and cleavage of existing protective groups, with examples to illustrate each new technique Expanded coverage of the unexpected side reactions that occur with protective groups New chart covering the selective deprotection of silyl ethers 3,100 new references from the professional literature The content is organized around the functional group to be protected, and ranges from the simplest to the most complex and highly specialized protective groups.
Download or read book Iron Catalysis written by Bernd Plietker and published by Springer Science & Business Media. This book was released on 2011-01-05 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: Juan I. Padrón and Víctor S. Martín: Catalysis by means of Fe-based Lewis acids; Hiroshi Nakazawa*, Masumi Itazaki: Fe–H Complexes in Catalysis; Kristin Schröder, Kathrin Junge, Bianca Bitterlich, and Matthias Beller: Fe-catalyzed Oxidation Reactions of Olefins, Alkanes and Alcohols: Involvement of Oxo- and Peroxo Complexes; Chi-Ming Che, Cong-Ying Zhou, Ella Lai-Ming Wong: Catalysis by Fe=X Complexes (X=NR, CR2); René Peters, Daniel F. Fischer and Sascha Jautze: Ferrocene and Half Sandwich Complexes as Catalysts with Iron Participation; Markus Jegelka, Bernd Plietker: Catalysis by Means of Complex Ferrates.
Book Synopsis Asymmetric Phase Transfer Catalysis by : Keiji Maruoka
Download or read book Asymmetric Phase Transfer Catalysis written by Keiji Maruoka and published by John Wiley & Sons. This book was released on 2008-09-08 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Edited by the leading expert on the topic, this is the first book to present the latest developments in this exciting field. Alongside the theoretical aspects, the top contributors provide practical protocols to give readers additional important information otherwise unavailable. A must for every synthetic chemist in academia and industry.
Book Synopsis Iron Catalysis in Organic Chemistry by : Bernd Plietker
Download or read book Iron Catalysis in Organic Chemistry written by Bernd Plietker and published by John Wiley & Sons. This book was released on 2008-09-08 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first comprehensive book to cover this exciting field also deals with the biological aspects, such as enzymes with iron. Following an introduction, this handy reference and handbook goes on to deal with reductions, oxidations of C, H- and C=C bonds, oxidative allylic oxygenation and amination, the oxidation of heteroatoms, cross coupling reactions, aromatic and nucleophilic substitutions, addition to carbonyl compounds, and cyclisations as well as ring opening reactions. The chapters are clearly classified according to the reaction type, allowing readers to quickly locate the desired information.
Book Synopsis Heterocyclic N-Oxides by : Oleg V. Larionov
Download or read book Heterocyclic N-Oxides written by Oleg V. Larionov and published by Springer. This book was released on 2017-07-12 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Topics in Heterocyclic Chemistry presents critical reviews on present and future trends in the research of heterocyclic compounds. Overall the scope is to cover topics dealing with all areas within heterocyclic chemistry, both experimental and theoretical, of interest to the general heterocyclic chemistry community. The series consists of topic related volumes edited by renowned editors with contributions of experts in the field. All chapters from Topics in Heterocyclic Chemistry are published Online First with an individual DOI. In references, Topics in Heterocyclic Chemistry is abbreviated as Top Heterocycl Chem and cited as a journal.
Book Synopsis Hypervalent Iodine Chemistry by : Viktor V. Zhdankin
Download or read book Hypervalent Iodine Chemistry written by Viktor V. Zhdankin and published by John Wiley & Sons. This book was released on 2013-10-01 with total page 630 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hypervalent Iodine Chemistry is the first comprehensive text covering all of the main aspects of the chemistry of organic and inorganic polyvalent iodine compounds, including applications in chemical research, medicine, and industry. Providing a comprehensive overview of the preparation, properties, and synthetic applications of this important class of reagents, the text is presented in the following way: The introductory chapter provides a historical background and describes the general classification of iodine compounds, nomenclature, hypervalent bonding, structural features, and the principles of reactivity of polyvalent iodine compounds. Chapter 2 gives a detailed description of the preparative methods and structural features of all known classes of organic and inorganic derivatives of polyvalent iodine. Chapter 3, the key chapter of the book, deals with the many applications of hypervalent iodine reagents in organic synthesis. Chapter 4 describes the most recent achievements in hypervalent iodine catalysis. Chapter 5 deals with recyclable polymer-supported and nonpolymeric hypervalent iodine reagents. Chapter 6 covers the "green" reactions of hypervalent iodine reagents under solvent-free conditions or in aqueous solutions. The final chapter provides an overview of the important practical applications of polyvalent iodine compounds in medicine and industry. This book is aimed at all chemists interested in iodine compounds, including academic and industrial researchers in inorganic, organic, physical, medicinal, and biological chemistry. It will be particularly useful to synthetic organic and inorganic chemists, including graduate and advanced undergraduate students. It comprehensively covers the green chemistry aspects of hypervalent iodine chemistry, making it especially useful for industrial chemists.
Book Synopsis Dienamine Catalysis for Organic Synthesis by : Kengadarane Anebouselvy
Download or read book Dienamine Catalysis for Organic Synthesis written by Kengadarane Anebouselvy and published by Royal Society of Chemistry. This book was released on 2018-03-02 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last decade a new era in asymmetric catalysis has been realised by the discovery of L-proline induced chiral enamines from carbonyls. Inspired by this, researchers have developed many other primary catalytic species in situ, more recently secondary catalytic species such as aminals have been identified for use in asymmetric synthesis. High-yielding asymmetric synthesis of bioactive and natural products through mild catalysis is an efficient approach in reaction engineering. In the early days, synthetic chemists mainly focused on the synthesis of complex molecules, with less attention on the reaction efficiency and eco-friendly conditions. Recent investigations have been directed towards the development of atom economy, eco-friendly and enantioselective synthesis for more targeted and efficient synthesis. Building on the momentum of this rapidly expanding research area, Dienamine catalysis for organic synthesis will provide a comprehensive introduction, from the preformed species, in situ generation and onto their applications in the synthesis of bioactive molecules and natural products.
Book Synopsis Total Synthesis of Natural Products by : Jie Jack Li
Download or read book Total Synthesis of Natural Products written by Jie Jack Li and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: 'Total Synthesis of Natural Products' is written and edited by some of today's leaders in organic chemistry. Eleven chapters cover a range of natural products, from steroids to alkaloids. Each chapter contains an introduction to the natural product in question, descriptions of its biological and pharmacological properties and outlines of total synthesis procedures already carried out. Particular emphasis is placed on novel methodologies developed by the respective authors and their research groups. This text is ideal for graduate and advanced undergraduate students, as well as organic chemists in academia and industry.
Book Synopsis Aziridines and Epoxides in Organic Synthesis by : Andrei K. Yudin
Download or read book Aziridines and Epoxides in Organic Synthesis written by Andrei K. Yudin and published by John Wiley & Sons. This book was released on 2006-02-20 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aziridines and epoxides are among the most widely used intermediates in organic synthesis, acting as precursors to complex molecules due to the strains incorporated in their skeletons. Besides their importance as reactive intermediates, many biologically active compounds also contain these three-membered rings. Filling a gap in the literature, this clearly structured book presents the much needed information in a compact and concise way. The renowned editor has succeeded in gathering together excellent authors to cover synthesis, applications, and the biological aspects in equal depth. Divided roughly equally between aziridines and epoxides, the twelve chapters discuss: * Synthesis of aziridines * Nucleophilic ring-opening of aziridines and epoxides * Organic synthesis with aziridine building blocks * Vinyl aziridines in organic synthesis * Diastereoselective aziridination reagents * Synthetic aspects of aziridinomitocene chemistry * Biosynthesis of biologically important aziridines * Organic catalysis of epoxide and aziridine ring formation * Metal-mediated synthesis of epoxides * Asymmetric epoxide ring opening chemistry * Epoxides in complex molecule synthesis * Biological activity of epoxide-containing molecules A high-quality reference manual for academic and industrial chemists alike.
