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Enantioselective Formal Total Synthesis Of Aspergillide C Iodine Mediated Oxidation Of Nitrogen Heterocycles Directed Towards Natural Product Synthesis
Download Enantioselective Formal Total Synthesis Of Aspergillide C Iodine Mediated Oxidation Of Nitrogen Heterocycles Directed Towards Natural Product Synthesis full books in PDF, epub, and Kindle. Read online Enantioselective Formal Total Synthesis Of Aspergillide C Iodine Mediated Oxidation Of Nitrogen Heterocycles Directed Towards Natural Product Synthesis ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Enantioselective Formal Total Synthesis of (+)-aspergillide C ; Iodine-mediated Oxidation of Nitrogen Heterocycles Directed Towards Natural Product Synthesis by : Joseph David Panarese
Download or read book Enantioselective Formal Total Synthesis of (+)-aspergillide C ; Iodine-mediated Oxidation of Nitrogen Heterocycles Directed Towards Natural Product Synthesis written by Joseph David Panarese and published by . This book was released on 2012 with total page 638 pages. Available in PDF, EPUB and Kindle. Book excerpt: A facile aromatization of tetrahydro-[Greek bata]-carbolines with both phenyl and aliphatic substituents at C-I has been accomplished. This oxidation, mediated by 2-iodoxybenzoic acid, occurs at room temperchure in two hours. A library of aromatic [Greek beta]-carbolines has been produced, and this methodology has been utilized in a total synthesis of the marine bis-indole alkaloid eudistomin U.
Book Synopsis Strategies and Tactics in Organic Synthesis by : Joseph D. Panarese
Download or read book Strategies and Tactics in Organic Synthesis written by Joseph D. Panarese and published by Elsevier Inc. Chapters. This book was released on 2013-07-29 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 2008, (+)-aspergillide C, a structurally novel marine metabolite bearing a 14-membered macrolactone around a 2,6-dihydropyran core, was isolated from a marine-derived fungus, Aspergillus ostianus. In a biological assay, (+)-aspergillide C displayed promising anticancer activity (LD50=2.0μg/ml) against mouse lymphocytic leukemia cells (L1210). Due to its notable biological activity and interesting architecture, we viewed aspergillide C as an attractive synthetic target. Moreover, the aspergillide scaffold could lend itself to diverse structural modifications in projected syntheses of biologically active congeners. In this account, we describe our enantioselective approach to aspergillide C from (S)-(−)-glyceraldehyde acetonide and the Danishefsky–Kitahara diene. Strategic transformations include a heterocyclocondensation reaction, a Ferrier-type addition, and a palladium-catalyzed oxidative lactonization to set key stereocenters within the dihydropyran core, followed by fragment coupling through an (E)-selective Julia–Kocienski olefination.
Book Synopsis Enantioselective Total Synthesis Of Diverse, Bioactive Natural Products by :
Download or read book Enantioselective Total Synthesis Of Diverse, Bioactive Natural Products written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Natural product synthesis is one of the most creative branch of chemistry in terms of its boundless scope for innovation and has stimulated several generations of synthetic organic chemists. With advancement in the technology, particularly in the isolation and purification techniques, high-field NMR and X-ray crystallography, it has become fairly routine to isolate and assign the structures, high-field NMR and X-ray crystallography, it has become fairly routine to isolate and assign the structures, even to those complex molecules, which are available only in microscopic quantities from natural sources. Concurrently, one has witnessed tremendous advances in the availability of new synthetic methodologies with high region-, stereo-, and enantiocontrol for one or multiple C-C bond formations and rapid generation of molecular complexity. These developments have rekindled interest with total synthesis of natural products as platforms for testing and validating new reactions and strategies. Many natural products exhibit wide range of biological activities and thus provide good leads in drug discovery but quite often such bioactive compounds are obtained only in minute quantities from Nature. Hence, there is need to synthesize them to obtain requisite quantities and build diversity around their scaffold to further explore their therapeutic potential. Thus, natural product synthesis combines both intellectual challenge and possible application for human wellbeing. Our research group is actively engaged in the synthesis of structurally complex, bioactive natural products and as a part of this endeavour, total syntheses of several bioactive compounds have been accomplished in our laboratory in recent past. The present thesis has also evolved around the ongoing theme directed towards natural product synthesis and is organized under three chapters. Chapter I: Total synthesis of (+)-1S-Minwanenone Chapter II: Enantioselective total synthesis of the bioactive natural product (+)-
Book Synopsis Enantioselective Organocatalyzed Reactions I by : Rainer Mahrwald
Download or read book Enantioselective Organocatalyzed Reactions I written by Rainer Mahrwald and published by Springer Science & Business Media. This book was released on 2011-08-03 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Transition Metal Catalyzed Enantioselective Allylic Substitution in Organic Synthesis by : Uli Kazmaier
Download or read book Transition Metal Catalyzed Enantioselective Allylic Substitution in Organic Synthesis written by Uli Kazmaier and published by Springer. This book was released on 2011-10-28 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Development of the Enantioselective Oxidation of Secondary Alcohols and Natural Products Total Synthesis by : Jeffrey Thomas Bagdanoff
Download or read book Development of the Enantioselective Oxidation of Secondary Alcohols and Natural Products Total Synthesis written by Jeffrey Thomas Bagdanoff and published by . This book was released on 2006 with total page 758 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Asymmetric Metal Catalysis in Enantioselective Domino Reactions by : Helene Pellissier
Download or read book Asymmetric Metal Catalysis in Enantioselective Domino Reactions written by Helene Pellissier and published by John Wiley & Sons. This book was released on 2019-11-11 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Enantioselective Chemical Synthesis by : Elias J. Corey
Download or read book Enantioselective Chemical Synthesis written by Elias J. Corey and published by Elsevier. This book was released on 2013-10-23 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by world-renowned and best-selling experts, Nobel Laureate E. J. Corey and Laszlo Kurti, Enantioselective Chemical Synthesis offers an authoritative and comprehensive overview of the field's progress; the processes and tools for key formations; future development for complex, stereocontrolled (enantiomeric or diastereoisomeric) molecules; and valuable examples of multi-step syntheses. Utilizing a color-coded scheme to illustrate chemical transformations, Enantioselective Chemical Synthesis provides clear explanation and guidance through vital asymmetrical syntheses and insight into the next steps for the field. Researchers, professionals, and academics will benefit from this valuable, thorough, and unique resource. - In Part I, the authors present clearly, comprehensively and concisely the most useful enantioselective processes available to synthetic chemists. - Part II provides an extensive discussion of the most logical ways to apply these new enantioselective methods to the planning of syntheses of stereochemically complex molecules. This hitherto neglected area is essential for the advancement of enantioselective synthesis to a more rational and powerful level. - Part III describes in detail many reaction sequences which have been used successfully for the construction of a wide variety of complex target molecules - Clearly explains stereochemical synthesis in theory and practice - Provides a handy tool box for scientists wishing to understand and apply chiral chemical synthesis - Describes almost 50 real life examples of asymmetric synthesis in practice and examines how the chiral centers were introduced at key synthetic stages
Book Synopsis The Enantioselective Synthesis of Complex Natural Products by : Ryan E. Stites
Download or read book The Enantioselective Synthesis of Complex Natural Products written by Ryan E. Stites and published by . This book was released on 2005 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Efforts Directed Toward the Enantioselective Synthesis of Ircinianin by : Marshall Hartwell Parker
Download or read book Efforts Directed Toward the Enantioselective Synthesis of Ircinianin written by Marshall Hartwell Parker and published by . This book was released on 1991 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Approaches to the Enantioselective Total Synthesis of the Natural Product Neoliacinic Acid by : Steven D. Paget
Download or read book Approaches to the Enantioselective Total Synthesis of the Natural Product Neoliacinic Acid written by Steven D. Paget and published by . This book was released on 1997 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis NEW METHODOLOGIES FOR THE ASYMMETRIC SYNTHESES OF AMINES AND NITROGEN HETEROCYCLES FROM ENANTIOPURE SULFINIMINES (N-SULFINYL IMINES) by : HUI Qiu
Download or read book NEW METHODOLOGIES FOR THE ASYMMETRIC SYNTHESES OF AMINES AND NITROGEN HETEROCYCLES FROM ENANTIOPURE SULFINIMINES (N-SULFINYL IMINES) written by HUI Qiu and published by . This book was released on 2009 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this research was to development new methodologies for the asymmetric syntheses of amine and natural products from enantiopure sulfinimines (N-sulfinyl imines). In this context, new methods was devised for the asymmetric synthesis of 2,5-cis and trans-disubstituted pyrrolidines from 3-oxo pyrrolidine 2-phosphonates, prepared by an intramolecular metal carbenoid N-H insertion from a sulfinimine derived delta-amino-alpha-diazo- beta-ketophosphonate. Horner-Wadsworth-Emmos reaction of the 3-oxo pyrrolidine 2-phosphonates and aldehydes provided pyrrolidine enones. Hydrogenation (Pd/H2) of the pyrrolidine enones gave cis-2,5-disubstituted pyrrolidines. Luche reduction the pyrrolidine enones followed by a TFA-NaBH3CN mediated hydroxy directed reduction provided the 2,5-trans products. (+)-Preussin, a potent antiviral and antitumor agent was prepared in 9 steps in 28% overall yield from the sulfinimine. An acid catalyzed intramolecular Mannich cyclization of a sulfinimine-derived N-sulfinyl syn-alpha-methyl-beta-amino ketones was employed for the asymmetric synthesis of 2,3,5,6-tetrasubstituted piperidinones. The beta-amino ketones were prepare by treatment of prochiral lithium Weinreb amide enolates with enantiopure (E)-N-(4-(benzyloxy)butylidene)-2,4,6-triisopropylbenzenesulfinamide. This new methodology was highlighted in the first asymmetric synthesis of the poison frog alkaloid (-)-indolizidine 221T. By manipulation of water concentration in tetrahydrofuran, syn- and anti-2,3-diamino esters were prepared by treatment of the lithium enolate of N-(diphenylmethylene) glycine ethyl ester with sulfinimines. Anhydrous THF afforded enantiopure syn-2,3-diamino esters with a syn/anti selectivity of better than 25:1. In a THF-H2O the anti-2,3-diamino esters were formed. The mechanism involves the generation of H2O-LDA species in the formation of enolate which inhibited the retro-Mannich fragmentation in the diamino ester species. (SR,2S,3R)-(-)-Ethyl-2-(N,N-dibenzylamino)-3-N-(p-toluenesulfinyl)amino-pent-4-enoate was employed in an improved total synthesis of the anti-tumor antibiotic (-)-agelastatin A. A series of N-sulfinyl aza-Morita-Baylis-Hillman products were prepared by addition of vinylaluminum and N-methylmorpholine-N-oxide reagents to enantiopure N-(p-toluenesufinyl)- and N-(2-methypropanesulfinyl)-derived sulfinimines from the least hindered direction via a non-chelation control mechanism. Hydrogenation of the these acrylates with a rhodium(I) catalyst afforded anti-alpha-substituted-beta-amino esters with a anti/syn selectivity of better than 17:1. This new methodology is useful for the asymmetric synthesis of anti-alpha-alkyl-beta-amino esters, which are valuable chiral building blocks for the preparation of biologically active nitrogen-containing natural products.
Book Synopsis Studies Towards the Enantioselective Synthesis of Aspidosperma Natural Products by : Christopher Gartshore
Download or read book Studies Towards the Enantioselective Synthesis of Aspidosperma Natural Products written by Christopher Gartshore and published by . This book was released on 2013 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt: The indole alkaloid (-)-aspidophytine was isolated from Haplophyton cimicidium, a plant traditionally known throughout Mexico for its insecticidal properties. The structural complexity of (-)-aspidophytine, characterized by the presence of a bridging lactone and unsaturation in the C ring appended to the characteristic aspidosperma [6.5.6.6.5] ABCDE ring system, has made it an appealing target for total synthesis. This thesis details studies focused on the development of new chemical reactions, and strategies, applicable to the enantioselective synthesis of aspidosperma alkaloids, in particular (-)-aspidophytine. The first chapter provides an introduction to the natural product (-)-aspidophytine and its parent compound (+)-haplophytine, detailing previous synthetic approaches, and the specific challenges expected in realising this goal. The latter section describes the development of new approaches suited to the synthesis of (-)-aspidophytine. Chapter two introduces the application of transition metal/nitroxide based oxidation reactions for the kinetic resolution and desymmetrisation of alcohols. The chapter then details the synthesis and application of a range of chiral racemic bi-functional nitroxide catalysts for the oxidation of activated alcohols. The employment of these catalysts to the synthesis of a range of aldehydes is outlined and efforts towards the development of enantioselective variant are discussed. The third chapter of this thesis details the development of a palladium catalyzed enantioselective decarboxylative allylation reaction of heterocycles bearing the indolone motif. The reaction provided an expedient approach to the synthesis of enantioenriched indolecontaining heterocycles with good yields and high levels of enantioinduction achieved. The scope of this reaction was examined with the synthesis of a range of functionalised carbazolones and indolones achieved. Having successful assembled a range of enantioenriched carbazolones, chapter four discusses the derivatisation of these substrates towards the synthesis of aspidosperma natural products. Challenges encountered when attempting to construct the aspidosperma tetracyclic core are detailed, specifically, formation of the D-ring and diastereoselective reduction of the resultant cyclic imine are outlined. In addition, manipulation of the allyl functionality is outlined culminating in the formal synthesis of (-)-aspidophytine. Chapter five of this thesis describes a related class of compounds belonging to the kopsia family of alkaloids. This chapter gives a brief introduction to kopsia alkaloids, specifically the recently discovered (+)-kopsihainanine A and B, then details efforts towards the synthesis of these compounds from the enantioenriched carbazolones introduced in chapter 3. The chapter concludes by outlining the first enantioselective formal synthesis of (+)-kopsihainanine A. Finally, the sixth chapter contains experimental procedures utilised within this project and the spectroscopic data derived from the compounds introduced in the preceding chapters.
Book Synopsis Organic Synthesis by : Belakatte Parameshwarappa Nandeshwarappa
Download or read book Organic Synthesis written by Belakatte Parameshwarappa Nandeshwarappa and published by BoD – Books on Demand. This book was released on 2020-05-27 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book ‘Organic Synthesis - A Nascent Relook’ is a compendium of the recent progress in all aspects of organic chemistry including bioorganic chemistry, organo-metallic chemistry, asymmetric synthesis, heterocyclic chemistry, natural product chemistry, catalytic, green chemistry and medicinal chemistry, polymer chemistry, as well as analytical methods in organic chemistry. The book presents the latest developments in these fields. The chapters are written by chosen experts who are internationally known for their eminent research contributions. Organic synthesis is the complete chemical synthesis of a target molecule. In this book, special emphasis is given to the synthesis of various bioactive heterocycles. Careful selection of various topics in this book will serve the rightful purpose for the chemistry community and the industrial houses at all levels.
Book Synopsis Studies Toward the Synthesis of Ortho-quinol-derived Natural Products and Derivatives by : Suwei Dong
Download or read book Studies Toward the Synthesis of Ortho-quinol-derived Natural Products and Derivatives written by Suwei Dong and published by . This book was released on 2011 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: An enantioselective approach to bicyclo[2.2.2]octenone structures utilizing a copper-mediated asymmetric oxidative dearomatization/[4+2] dimerization cascade has been developed. This approach takes advantage of the diastereoselective dimerization of chiral ortho -quinols, which arc prepared from oxidation of disubstituted phenols with a [(-)-sparteine]2Cu202(PF6)2 complex. Utilizing this methodology, the total synthesis and absolute stereochemistry assignment of the novel bis -sesquiterpene (+)-aquaticol has been achieved. We have also investigated a retro-Diels-Alder/Diels-Alder cascade of enantiomerically pure ortho -quinol dimers. By utilizing a microwave-assisted parallel screen of dienophiles and dienes, the reactivity of ortho -quinols in [4+2] reactions has been evaluated. Computational studies have also been conducted in order to rationalize the observed diastereoselectivity. Furthermore, biological evaluation of prepared bicyclo[2.2.2]octenones and cis -decalins has identified an inhibitor of the transcription factor activator proteine-1 (AP-1). Utilizing the tandem retro-Diels-Alder/Diels-Alder reaction, the total synthesis of the microtubule inhibitor (+)-chamaecypanone C has been achieved. Moreover, rhodium- catalyzed dehydrogenation of diarylcyclopentenones has been developed to in situ generate the corresponding diarylcyclopentadienones, which were further elaborated into derivatives of chamaecypanone C. Initial biological studies demonstrate that (+)- chamaecypanone C is an inhibitor of tubulin assembly and binds at the colchicine site. A hypervalent iodine(III) reagent-mediated dearomatization/acyl migration cascade has been developed. Preliminary studies toward the synthesis of the antileukemic agent sorbicillactone A using this methodology, including the construction of the desired bicyclic core structure, will be described.
Book Synopsis Catalytic Enantioselective Synthesis of Oxindoles and Benzofuranones Bearing a Quaternary Stereocenter and Reactions of Palladium Bisphosphine Complexes Relevant to Catalytic C-C Bond Formation by : Ivory Derrick Hills
Download or read book Catalytic Enantioselective Synthesis of Oxindoles and Benzofuranones Bearing a Quaternary Stereocenter and Reactions of Palladium Bisphosphine Complexes Relevant to Catalytic C-C Bond Formation written by Ivory Derrick Hills and published by . This book was released on 2004 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Application of the Type 2 Intramolecular Diels-Alder Reaction to Natural Product Synthesis: I. an Enantioselective Total Synthesis of (+)-adrenosterone ; II. Studies Toward the Synthesis of 9-deoxyphorbol by : Carolyn Diane Dzierba
Download or read book Application of the Type 2 Intramolecular Diels-Alder Reaction to Natural Product Synthesis: I. an Enantioselective Total Synthesis of (+)-adrenosterone ; II. Studies Toward the Synthesis of 9-deoxyphorbol written by Carolyn Diane Dzierba and published by . This book was released on 1997 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt:
