Synthesis and Reactivity of Donor-Acceptor Substituted Aminocyclopropanes and Aminocyclobutanes

Synthesis and Reactivity of Donor-Acceptor Substituted Aminocyclopropanes and Aminocyclobutanes PDF 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.

Synthesis and Reactivity of Donor-Acceptor Substituted Aminocyclopropanes and Aminocyclobutanes

Synthesis and Reactivity of Donor-Acceptor Substituted Aminocyclopropanes and Aminocyclobutanes PDF 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.

Donor-Acceptor Cyclopropanes in Organic Synthesis

Donor-Acceptor Cyclopropanes in Organic Synthesis PDF Author: Prabal Banerjee
Publisher: John Wiley & Sons
ISBN: 3527349871
Category : Science
Languages : en
Pages : 469

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Book Description
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.

Exploring the Reactivity of Donor-acceptor Cyclopropanes and the Synthesis of (+/- )-Quebrachamine

Exploring the Reactivity of Donor-acceptor Cyclopropanes and the Synthesis of (+/- )-Quebrachamine PDF 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.

Lewis Acid Catalyzed Annulations of Donor-Acceptor Aminocyclopropanes and Aminocyclobutanes

Lewis Acid Catalyzed Annulations of Donor-Acceptor Aminocyclopropanes and Aminocyclobutanes PDF Author: Sophie Lucie Racine
Publisher:
ISBN:
Category :
Languages : en
Pages : 459

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Book Description
Mots-clés de l'autrice: donor-acceptor aminocyclopropanes ; donor-acceptor aminocyclobutanes ; Lewis acid catalysis ; annulations ; (carbo)nucleoside analogs ; nitrogen substituted cyclopentylenamines ; polycyclic isooxindoles ; Aspidospermidine.

The Synthesis and Reactivity of Novel Donor-Acceptor Cyclopropanes and Progress Towards Pyrrolidine Alkaloids

The Synthesis and Reactivity of Novel Donor-Acceptor Cyclopropanes and Progress Towards Pyrrolidine Alkaloids PDF Author: Michael R. Emmett
Publisher:
ISBN:
Category :
Languages : en
Pages : 510

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Book Description
The first chapter of this thesis focuses on the synthesis and reactivity of cyclopropane hemimalonates. The cyclopropane hemimalonates can easily be synthesized from 1,1-cyclopropanediesters. The reactivity of cyclopropane hemimalonates with indole under ultra-high pressure conditions leads to ring opened adducts that are complementary to previous research in the Kerr group. The tandem ring opening decarboxylation reaction of cyclopropane hemimalonates led to the synthesis of -aminobutyric acid analogues. When an external nucleophile was not present, the cyclopropane hemimalonates could rearrange to form butyrolactones in good to excellent yields. The stereochemical integrity of the cyclopropane hemimalonate is retained through this process, which is not usually seen in cyclopropane reactivity. The second chapter describes the progress towards the synthesis of Kainic acid. While the progress towards this natural product appeared to be going well, after closer analysis of the products, a new reactivity of diazo species and cyclopentadiene was realized. In the third chapter, the progress towards the synthesis of Actinophyllic acid is provided. Synthesis of advanced intermediates was completed, however the key formation of a 1,4-dicarbonyl species of the pyrrolidine ring eluded this study.

Synthesis and Properties of Donor/acceptor Substituted Expanded Radialenes

Synthesis and Properties of Donor/acceptor Substituted Expanded Radialenes PDF Author: Sharwatie Ramsaywack
Publisher:
ISBN:
Category : Carbon compounds
Languages : en
Pages : 380

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Book Description


Iron Catalysis

Iron Catalysis PDF Author: Bernd Plietker
Publisher: Springer Science & Business Media
ISBN: 3642146694
Category : Science
Languages : en
Pages : 227

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Book Description
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.

Iron Catalysis in Organic Chemistry

Iron Catalysis in Organic Chemistry PDF Author: Bernd Plietker
Publisher: John Wiley & Sons
ISBN: 3527623280
Category : Science
Languages : en
Pages : 295

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Book Description
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.

Catalytic Reduction in Organic Synthesis

Catalytic Reduction in Organic Synthesis PDF Author: Johannes G. de Vries
Publisher: Thieme Chemistry
ISBN: 9783132406223
Category : Catalysis
Languages : en
Pages : 0

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Book Description
Catalytic reductions are among the most used synthetic transformations, and the past 15 years have seen great progress in this field. Science of Synthesis: Catalytic Reduction in Organic Synthesis includes the latest developments, as well as selective coverage of more well-established methods. Both heterogeneous and homogeneous catalytic systems are covered, and enantioselective methodology is well represented. There is a focus on the use of metal nanoparticles, both in suspension as well as on solid supports. Furthermore, the advent of research on the conversion of renewable resources into fuels and chemicals has given a great impetus to the field, as deoxygenations are often the first step in the conversion of biomass and this can often be achieved using hydrogenation or hydrogenolysis reactions. Scope, limitations, and mechanism of the reactions are discussed and key experimental procedures are included.

Methods and Applications of Cycloaddition Reactions in Organic Syntheses

Methods and Applications of Cycloaddition Reactions in Organic Syntheses PDF Author: Nagatoshi Nishiwaki
Publisher: John Wiley & Sons
ISBN: 1118778200
Category : Science
Languages : en
Pages : 996

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Book Description
Advanced tools for developing new functional materials and applications in chemical research, pharmaceuticals, and materials science Cycloadditions are among the most useful tools for organic chemists, enabling them to build carbocyclic and heterocyclic structures. These structures can then be used to develop a broad range of functional materials, including pharmaceuticals, agrochemicals, dyes, and optics. With contributions from an international team of leading experts and pioneers in cycloaddition chemistry, this book brings together and reviews recent advances, trends, and emerging research in the field. Methods and Applications of Cycloaddition Reactions in Organic Syntheses focuses on two component cycloadditions, with chapters covering such topics as: N1 unit transfer reaction to C–C double bonds [3+2] Cycloaddition of α, β-unsaturated metal-carbene complexes Formal [3+3] cycloaddition approach to natural product synthesis Development of new methods for the construction of heterocycles based on cycloaddition reaction of 1,3-dipoles Cycloreversion approach for preparation of large π-conjugated compounds Transition metal-catalyzed or mediated [5+1] cycloadditions Readers will learn methods for seamlessly executing important reactions such as Diels-Alder and stereoselective dipolar reactions in order to fabricate heterocyclic compounds, natural products, and functional molecules. The book not only features cutting-edge topics, but also important background information, such as the contributors’ process for developing new methodologies, to help novices become fully adept in the field. References at the end of each chapter lead to original research papers and reviews for facilitating further investigation of individual topics. Covering the state of the science and technology, Methods and Applications of Cycloaddition Reactions in Organic Syntheses enables synthetic organic chemists to advance their research and develop new functional materials and applications in chemical research, pharmaceuticals, and materials science.