Author: Prabal Banerjee
Publisher: John Wiley & Sons
ISBN: 3527835644
Category : Science
Languages : en
Pages : 469
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Book Description
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.
Author: Oleg G. Kulinkovich
Publisher: John Wiley & Sons
ISBN: 1118057430
Category : Science
Languages : en
Pages : 428
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Book Description
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
Author: Kengadarane Anebouselvy
Publisher: Royal Society of Chemistry
ISBN: 1782620907
Category : Science
Languages : en
Pages : 220
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Book Description
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.
Author: Florian de Nanteuil
Publisher: Springer
ISBN: 3319230069
Category : Science
Languages : en
Pages : 329
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Book Description
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.
Author: Michael P. Doyle
Publisher: Wiley-Interscience
ISBN:
Category : Science
Languages : en
Pages : 680
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Book Description
This much-needed resource brings together a wealth of procedures for the synthesis and practical use of diazocarbonyl compounds. It features methods for the preparation of important catalysts and for applications of diazocarbonyl compounds within each of the main transformation categories-including in-depth coverage of cyclopropanation, C-H and X-H insertion, Wolff rearrangement, ylide formation, aromatic cycloaddition and substitution, and many other useful reactions. Written by leading experts in the field, this book contains cutting-edge material on highly enantioselective transformations, and presents new ways of thinking about diazocarbonyl compounds and their applications, from donor-acceptor cyclopropanes in organic synthesis to macrocyclic cyclopropanation. Complete with illustrative examples of procedures in each chapter, clear diagrams, and a detailed bibliography, this practical reference gives readers the tools they need to put diazocarbonyl compounds to work for their own projects-an invaluable source of guidance for synthetic organic chemists, chemical scientists, and advanced students.
Author: Tristan Chidley
Publisher:
ISBN:
Category :
Languages : en
Pages : 252
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Book Description
Cyclopropane 1,1-diesters have been investigated as a source of donor-acceptor cyclopropanes, providing an understanding of the mechanism of reaction between these cyclopropanes and nitrosoarenes, as well as azo dicarboxylates. Cross-over experiments have been utilized to provide key pieces of experimental evidence that help generate a theoretical model of the reactions. By understanding these reactions with precision, the avenue to expand the reaction scope and develop other useful reactions is opened up. This allows the chemistry to be better utilized, providing easier access to important molecules when needed, and contributes to advancing the field of synthetic organic chemistry. In addition, cyclobutane 1,1-diesters were also investigated as a source of donor-acceptor cyclobutanes. Specifically, their use in cycloaddition reactions has been developed to include the reaction of cyclobutanes with cis-diazenes, providing access to hexahydropyridazines. These compounds are synthesized in an efficient manner and are known to contain biologically active properties.
Author: Huck K. Grover
Publisher:
ISBN:
Category :
Languages : en
Pages : 556
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Book Description
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.
Author: Eder João Lenardão
Publisher: Elsevier
ISBN: 0128194502
Category : Science
Languages : en
Pages : 341
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Book Description
Organochalcogen compounds reviews the state of the art in new green protocols involving organochalcogen compounds (Se, S, and Te), including the use of nonconventional reaction media, alternative solvents, and solvent-free protocols to prepare these important compounds. Bringing together several leading researchers in organochalcogen chemistry, it provides an authoritative overview of the current state of the field and compiles recent advances in methodologies for the application of green chemistry principles in compound development. These include the use of organochalcogen compounds as intermediates, catalysts, or target products across a range of applications. The recent developments outlined in in the book reflect the efforts of the researchers in this area to move toward a more sustainable chemistry, giving the book the dual benefit of highlighting the latest developments in the field while also showing how the principles of green chemistry can effectively be included in active research projects. Thus it is a valuable reference for chemists, particularly those working in organic, green, and synthetic chemistry across both academia and industry. Highlights green synthetic methods with potential application in the synthesis of natural compounds or other biologically active scaffolds Explores the chemical modification of natural compounds by insertion of organochalcogen groups for the preparation of boosted bioactive semisynthetic molecules Discuss how redox catalysis and catalysis in flow conditions using eco-friendly oxidant can provide new opportunities for the synthesis of linear ad cyclic derivatives
Author: Jianbo Wang
Publisher: John Wiley & Sons
ISBN: 3527829156
Category : Science
Languages : en
Pages : 450
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Book Description
Presents an up-to-date overview of the rapidly growing field of carbene transformations Carbene transformations have had an enormous impact on catalysis and organometallic chemistry. With the growth of transition metal-catalyzed carbene transformations in recent decades, carbene transformations are today an important compound class in organic synthesis as well as in the pharmaceutical and agrochemical industries. Edited by leading experts in the field, Transition Metal-Catalyzed Carbene Transformations is a thorough summary of the most recent advances in the rapidly expanding research area. This authoritative volume covers different reaction types such as ring forming reactions and rearrangement reactions, details their conditions and properties, and provides readers with accurate information on a wide range of carbene reactions. Twelve in-depth chapters address topics including carbene C-H bond insertion in alkane functionalization, the application of engineered enzymes in asymmetric carbene transfer, progress in transition-metal-catalyzed cross-coupling using carbene precursors, and more. Throughout the text, the authors highlight novel catalytic systems, transformations, and applications of transition-metal-catalyzed carbene transfer. Highlights the dynamic nature of the field of transition-metal-catalyzed carbene transformations Summarizes the catalytic radical approach for selective carbene cyclopropanation, high enantioselectivity in X-H insertions, and bio-inspired carbene transformations Introduces chiral N,N'-dioxide and chiral guanidine-based catalysts and different transformations with gold catalysis Discusses approaches in cycloaddition reactions with metal carbenes and polymerization with carbene transformations Outlines multicomponent reactions through gem-difunctionalization and transition-metal-catalyzed cross-coupling using carbene precursors Transition Metal-Catalyzed Carbene Transformations is essential reading for all chemists involved in organometallics, including organic and inorganic chemists, catalytic chemists, and chemists working in industry.
Author: Oleg G. Kulinkovich
Publisher: John Wiley & Sons
ISBN: 1118978412
Category : Science
Languages : en
Pages : 428
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Book Description
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
