Download or read book Preparation and Reactivity of a Novel Donor acceptor Cyclopropane written by Xiaomei Zheng and published by . This book was released on 2006 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Donor Acceptor Cyclopropanes in Organic Synthesis written by Prabal Banerjee and published by John Wiley & Sons. This book was released on 2024-05-06 with total page 469 pages. Available in PDF, EPUB and Kindle. Book excerpt: Facilitate milder, simpler reactions in organic synthesis with this cutting-edge family of building blocks Donor-Accepted Cyclopropanes, or DACs, have attracted a resurgence of interest from organic chemists in recent decades for their role in facilitating various reactions such as cycloadditions, annulations, ring-opening and enantioselective transformations. The structural arrangement of DACs leads to milder, simpler reaction conditions, which have made them indispensable for a range of fundamentally and industrially important processes. Donor-Acceptor Cyclopropanes in Organic Synthesis covers comprehensively the chemistry and applications of this compound class. The result is an invaluable guide for any researcher looking to bring DACs to bear in their own areas of research or development. Readers will also find: A brief introduction of the history and reactivity of DACs Detailed discussion of reactions including Lewis acid-catalyzed cycloadditions, metal-free activation, asymmetric transformations, organocatalysis, and many more Application of DACs in natural product synthesis and pharmaceutical/agrochemical research Donor-Acceptor Cyclopropanes in Organic Synthesis is ideal for organic chemists, experts in catalysis, pharmaceutical researchers, and any other scientists interested in facilitating milder, simpler reactions.
Download or read book Synthesis and Reactivity of Donor Acceptor Substituted Aminocyclopropanes and Aminocyclobutanes written by Florian de Nanteuil and published by Springer. This book was released on 2015-09-26 with total page 329 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a general approach to accessing nitrogen-substituted hetero- and carbocycles. In short, the annulation reactions developed in the thesis make it possible to access nitrogen-substituted four-, five- and six-membered rings, all essential building blocks for the synthesis of bioactive molecules. Many natural products display a saturated polycyclic core allowing a well-defined arrangement of functional groups in space. As such, they can interact with biological targets with a high degree of affinity and selectivity, surpassing many synthetic drugs. Nevertheless, the efficient synthesis of such complex ring systems poses a challenge for organic chemistry. Through careful tuning of the electronic properties of a nitrogen donor group and a diester acceptor group, the first [3+2] annulation reaction between aminocyclopropanes and enol ethers or carbonyl compounds is now possible. The reaction proceeded under mild catalytic conditions, and the building blocks obtained can be found at the core of bioactive alkaloids, drugs such as Ramipril and biomolecules such as DNA and RNA. Thanks to the dynamic kinetic asymmetric annulation of aminocyclopropanes with enol ethers and aldehydes, access to enantioenriched compounds is also now possible. Lastly, a synthesis of donor-acceptor aminocyclobutanes via [2+2] cycloaddition using a cheap iron catalyst was developed, allowing them to be used in [4+2] annulations to access cyclohexylamines.
Download or read book Cyclopropanes in Organic Synthesis written by Oleg G. Kulinkovich and published by John Wiley & Sons. This book was released on 2015-11-02 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a practical guidebook about cyclopropanes that thoroughly surveys derivatives and transformations, synthetic methods, and experimental efficiency as a gateway for further research and development in the field. • Provides comprehensive lists and synthetically-oriented synopses of cyclopropane chemistry review references along with publication data on applications in the syntheses of natural and related biologically active compounds • Acts as a resource to help readers better understand cyclopropane applications for the efficient realization of synthetically important organic transformations and popular experimental procedures • Includes new developments and up-to-date information that will lead to original methodologies for complex organic synthesis • Stresses universality, flexibility, and experimental efficiency of a strategy based on preparing cyclopropane derivatives and performing ring cleavage reactions with inexpensive reagents • Focuses on the synthetic potential of cyclopropane applications, for example the synthesis of natural compounds and other target-oriented syntheses via cyclopropane intermediaries, as well on their planning by retrosynthetic analysis
Download or read book Exploring the Reactivity of Donor acceptor Cyclopropanes and the Synthesis of Quebrachamine written by Huck K. Grover and published by . This book was released on 2014 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development and utility of cyclopropanes is an ever-growing field within organic chemistry. In particular, donor-acceptor cyclopropanes have been used in a vast array of methods to access a variety of different hetero and carbocyclic molecular scaffolds. Recently, we have developed a Zn(NTf2)2 catalyzed tandem reaction consisting of a nucleophilic ringopening of 1,1-cyclopropanediesters by 2-alkynyl indoles followed by a Conia-ene ring closure, resulting in the efficient one-step synthesis of tetrahydrocarbazoles. These adducts may be further elaborated to carbazoles. The scope and limitations of this method were determined along with a mechanistic study into the function of the zinc catalyst. In an expansion of our work with 1,1-cyclopropanediesters, we have explored the reactivity and utilization of hemimalonate cyclopropanes. To this end, we have developed two unique methods exploring the self-activating nature of these cyclopropanes under catalyst free conditions. Cyclopropane hemimalonates, when treated with sodium azide, undergo a tandem ring-opening decarboxylation to produce?-azidobutyric acids in good yields. These adducts were hydrogenated to form?-aminobutyric acid (GABA) methyl esters. Additionally, cyclopropane hemimalonates have led to the facile synthesis of?-substituted butanolides. Under microwave irradiation, cyclopropane hemimalonates undergo rapid conversion to butanolides in the presence of inorganic salts with an unprecedented retention of stereochemistry. This unique process, in conjunction with a newly developed crossmetathesis method, has been applied to the total synthesis of the naturally occurring, (R)- dodecan-4-olide. Finally, recent efforts to develop a unified approach to piperidine-containing indole natural products have shown great promise. A preliminary investigation into the prospect of a common synthetic intermediate for the synthesis of a variety of indole alkaloids has led to a synthesis of substituted piperidinones and the corresponding piperidines. These common natural product cores are accessed via a reductive amination/lactamization sequence of dimethyl 3-ethyl-3-formylpimelate. The synthetic utility of this initial study has been displayed in the formal synthesis of (+/- )-quebrachamine.
Download or read book The Application of Novel Donor Acceptor Cyclopropanes in the Synthesis of Linearly Fused Tricyclic Triazoles written by Michelle Elaine Flisar and published by . This book was released on 2014 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Previous work in the Kerr group has shown the su ccess of donor-acceptor cyclopropanes as substrates in a variety of synthetic reactions; this document will apply the use of donor acceptor cyclopropanes in various synthetic reactions. This was done using a 2-substituted 1,1 - cyclopropanediester, in the Overman Rearrangement, which has yet to be explored using DA cyclopropanes. Another useful DA cyclopropane is the novel a cetylene-bearing donor acceptor diester cyclopropanes which would be synthetically useful in a wide variety of reactions. In particular, the Conia-ene cyclization occurred intramolecularly with this alkyne DA cyclopropane with a large library of nucleophiles. Finally, taking this acetylene-bearing DA cyclopropane, it was converted to the hemimalonate version, and subjected to a ring-opening by azide as the nucleophile to generate an alkyl azide; which then underwent a [3+2] dipolar cycloaddition with the alkyne to form novel linearly fused tricyclic triazoles.
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.
Download or read book Donor Acceptor Cyclopropanes in Organic Synthesis written by Prabal Banerjee and published by John Wiley & Sons. This book was released on 2024-02-09 with total page 469 pages. Available in PDF, EPUB and Kindle. Book excerpt: Donor-Acceptor Cyclopropanes in Organic Synthesis Facilitate milder, simpler reactions in organic synthesis with this cutting-edge family of building blocks Donor-Accepted Cyclopropanes, or DACs, have attracted a resurgence of interest from organic chemists in recent decades for their role in facilitating various reactions such as cycloadditions, annulations, ring-opening and enantioselective transformations. The structural arrangement of DACs leads to milder, simpler reaction conditions, which have made them indispensable for a range of fundamentally and industrially important processes. Donor-Acceptor Cyclopropanes in Organic Synthesis covers comprehensively the chemistry and applications of this compound class. The result is an invaluable guide for any researcher looking to bring DACs to bear in their own areas of research or development. Readers will also find: A brief introduction of the history and reactivity of DACs Detailed discussion of reactions including Lewis acid-catalyzed cycloadditions, metal-free activation, asymmetric transformations, organocatalysis, and many more Application of DACs in natural product synthesis and pharmaceutical/agrochemical research Donor-Acceptor Cyclopropanes in Organic Synthesis is ideal for organic chemists, experts in catalysis, pharmaceutical researchers, and any other scientists interested in facilitating milder, simpler reactions.
Download or read book Synthesis of Novel Functionalised Calix n phyrin Porphyrin and Chlorin Derivates Using Donor acceptor substituted Cyclopropane Precursors written by Mohammad Hassan Beyzavi and published by . This book was released on 2013 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reactivity Studies of Donor Acceptor Cyclopropanes written by Alexander Kreft and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Total Synthesis of goniomitine Via a 3 2 Cyclization with Donor acceptor Cyclopropane written by Christian Leonardo Morales and published by . This book was released on 2007 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Donor acceptor Cyclopropanes as Building Blocks for the Synthesis of Natural Product Scaffolds written by Sinan Gai and published by . This book was released on 2018 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first chapter of this thesis provides an introduction to natural products and describes how they are a valuable source of bioactive compounds, which feature heavily in clinically used drugs. The recently reported bioactive natural product maoecrystal V was introduced followed by the chemistry of cyclopropanes, which were intended to be used in the synthesis of maoecrystal V.Synthetic strategies towards the synthesis of maoecrystal V were investigated in chapter 2. A retrosynthetic analysis of maoecrystal V was proposed, which featured a cyclopropane ring expansion. Using a model system, the key step, an intermolecular Diels-Alder cycloaddition was used to construct the [2.2.2]-bicyclooctane scaffold of maoecrystal V. Concurrently to this work, Baran and co-workers completed the synthesis of maoecrystal V and found that it possessed little to no bioactivity against a wide range of cancer cell lines.An introduction to spiroketals and the less common benzannulated spiroketals followed by the methodology to construct them are described in chapter 3. Based on some preliminary results from another study, attention was turned to utilising donor-acceptor cyclopropanes in the synthesis of benzannulated n,5-spiroketals (n = 6 or 5), which are found in numerous bioactive natural products.
Download or read book March s Advanced Organic Chemistry written by Michael B. Smith and published by John Wiley & Sons. This book was released on 2007-01-29 with total page 2379 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Sixth Edition of a classic in organic chemistry continues its tradition of excellence Now in its sixth edition, March's Advanced Organic Chemistry remains the gold standard in organic chemistry. Throughout its six editions, students and chemists from around the world have relied on it as an essential resource for planning and executing synthetic reactions. The Sixth Edition brings the text completely current with the most recent organic reactions. In addition, the references have been updated to enable readers to find the latest primary and review literature with ease. New features include: More than 25,000 references to the literature to facilitate further research Revised mechanisms, where required, that explain concepts in clear modern terms Revisions and updates to each chapter to bring them all fully up to date with the latest reactions and discoveries A revised Appendix B to facilitate correlating chapter sections with synthetic transformations
Download or read book Comprehensive Organic Synthesis written by and published by Newnes. This book was released on 2014-02-14 with total page 9815 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second edition of Comprehensive Organic Synthesis—winner of the 2015 PROSE Award for Multivolume Reference/Science from the Association of American Publishers—builds upon the highly respected first edition in drawing together the new common themes that underlie the many disparate areas of organic chemistry. These themes support effective and efficient synthetic strategies, thus providing a comprehensive overview of this important discipline. Fully revised and updated, this new set forms an essential reference work for all those seeking information on the solution of synthetic problems, whether they are experienced practitioners or chemists whose major interests lie outside organic synthesis. In addition, synthetic chemists requiring the essential facts in new areas, as well as students completely new to the field, will find Comprehensive Organic Synthesis, Second Edition, Nine Volume Set an invaluable source, providing an authoritative overview of core concepts. Winner of the 2015 PROSE Award for Multivolume Reference/Science from the Association of American Publishers Contains more than170 articles across nine volumes, including detailed analysis of core topics such as bonds, oxidation, and reduction Includes more than10,000 schemes and images Fully revised and updated; important growth areas—including combinatorial chemistry, new technological, industrial, and green chemistry developments—are covered extensively
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 Palladium catalyzed Asymmetric Formal 3 2 cycloadditions with Donor acceptor Cyclopropanes written by Patrick Joseph Morris and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The development of new methods for the synthesis of densely-functionalized enantioenriched five-membered hetero- and carbocycles is of importance in organic chemistry. Such functionalized five-membered ring are one of the motifs found in a wide array of biological targets. One atom- and step-economical method for the synthesis of these these five-membered ring systems is via a formal [3+2]-cycloaddition between a 1,3-dipole and a dipolarophile. Vicinally-substituted donor-acceptor cyclopropanes contain an electron-withdrawing group at the 1-position and an electron-donating group at the 2-position. This allows for their heterolytic cleavage to form a 1,3-dipoles under appropriate reaction conditions. Typically, Lewis acid-catalysis has been utilized to affect formal [3+2]-cycloadditions with donor-acceptor cyclopropanes. However, the use of palladium-catalysis to affect formal [3+2]-cycloadditions with donor-acceptor cyclopropanes has been relatively unexplored, and prior to this work had never been examined in an asymmetric fashion. The asymmetric allylic alkylation ligands developed by Trost and coworkers have been extensively used over the last 15 years in a variety of enantioselective reactions. However, the ability of these ligands to induce enantioselectivity in a bond-forming event two-bonds away from the [pi]-allyl-palladium center had never been demonstrated. The development of an asymmetric formal [3+2]-cycloaddition with donor-acceptor cyclopropanes and Meldrum's acid alkylidenes demonstrated the ability of this class of ligands to direct stereochemistry quite far away from the [pi]-allyl-palladium complex. A range of substituted cyclopentane derivatives were synthesized in this manner. An analysis of the relative stability of the donor-acceptor cyclopropanes in conjunction with the the palladium-ligand complex led to the development of a new class of donor-acceptor cyclopropane, the bis(2,2,2-trifluoroethyl)malonate-substituted vinyl cyclopropane. This new class of donor-acceptor cyclopropane was then utilized successfully in a formal [3+2]-cycloaddition with a variety of dipolarophiles, including the nitroolefins, isocyanates, and N-tosylimines. The azlactone alkylidenes, which represent protected amino acids, were further explored as dipolarophiles for this reaction, and a range of spirocyclic products were synthesized in high yield, enantiomeric excess and diastereomeric excess. Notably, three contiguous stereocenters were set in this reaction. In addition to this project, two approaches towards the synthesis of biyouyanagin A were explored. The initial approach, involving a proposed 11-endo-dig cyclization of an alcohol onto an alkyne ultimately proved to be unsuccessful. A secondary approach involved the use of a palladium-catalyzed dynamic kinetic asymmetric reaction between a hydroxyfuran and isoprene monoepoxide. Use of this strategy successfully synthesized hyperolactone C, which represented a formal synthesis of biyouyanagin A.
Download or read book Organic Chemistry Workbook written by Pierre Vogel and published by John Wiley & Sons. This book was released on 2019-08-20 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides references and answers to every question presented in the primary Organic Chemistry textbook Successfully achieving chemical reactions in organic chemistry requires a solid background in physical chemistry. Knowledge of chemical equilibria, thermodynamics, reaction rates, reaction mechanisms, and molecular orbital theory is essential for students, chemists, and chemical engineers. The Organic Chemistry presents the tools and models required to understand organic synthesis and enables the efficient planning of chemical reactions. This volume, Organic Chemistry: Theory, Reactivity, and Mechanisms in Modern Synthesis Workbook, complements the primary textbook—supplying the complete, calculated solutions to more than 800 questions on topics such as thermochemistry, pericyclic reactions, organic photochemistry, catalytic reactions, and more. This companion workbook is indispensable for those seeking clear, in-depth instruction on this challenging subject. Written by prominent experts in the field of organic chemistry, this book: Works side-by-side with the primary Organic Chemistry textbook Includes chapter introductions and re-stated questions to enhance efficiency Features clear illustrations, tables, and figures Strengthens reader?s comprehension of key areas of knowledge Organic Chemistry: Theory, Reactivity, and Mechanisms in Modern Synthesis Workbook is a must-have resource for anyone using the primary textbook.
