Investigations Into the Ruthenium Catalyzed Ring Opening and Dimerization Reactions of Oxabicyclic Alkenes

Investigations Into the Ruthenium Catalyzed Ring Opening and Dimerization Reactions of Oxabicyclic Alkenes PDF Author: Kelsey Jack
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Languages : en
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Investigations Into the Ruthenium Catalyzed Ring Opening and Dimerization Reactions of Oxabicyclic Alkenes

Investigations Into the Ruthenium Catalyzed Ring Opening and Dimerization Reactions of Oxabicyclic Alkenes PDF Author: Kelsey Jack
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Languages : en
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Rhodium-Catalyzed Asymmetric Ring Opening of Oxabicyclic Alkenes and Palladium-Catalyzed Carbon-Halogen Bond Forming Reactions

Rhodium-Catalyzed Asymmetric Ring Opening of Oxabicyclic Alkenes and Palladium-Catalyzed Carbon-Halogen Bond Forming Reactions PDF Author: Christine Le
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Languages : en
Pages : 0

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Atom-economical addition reactions to unsaturated carbonâ carbon bonds represent a powerful class of transformations in organic chemistry, since a great deal of molecular complexity can be generated from simple starting materials. Highly regio- and stereoselective processes have been made possible through the use of transition metal catalysts, alongside specialized ancillary ligands and in combination with rational substrate design. One area of research in the Lautens group involves the transition metal catalyzed asymmetric ring opening (ARO) of strained alkenes, which provides access to enantioenriched carbocyclic frameworks. Although a variety of coupling partners have been applied in this transformation, the use of soft carbon nucleophiles remains limited in scope. The first chapter describes a rhodium(I)-catalyzed ARO of meso-oxabicyclic alkenes using silyl enol ethers and ketene acetals. In analogy to the Mukaiyama aldol reaction, a novel silyl migration occurs, enabling an in situ protection of the chiral alcohols obtained. Developing new reactivity from Heck-type carbopalladation processes represents another research interest in the Lautens group. Oxidative addition into a carbonâ halogen bond constitutes the first step of nearly all palladium(0)-catalyzed cross-couplings. Conversely, reductive elimination from palladium(II) to yield an organohalide product represents a rare and often thermodynamically unfavoured process. The next two chapters address challenges in the synthesis of vinyl halides using palladium(0) catalysis via the intramolecular carbohalogenation and chlorocarbamoylation of alkynes. During our investigations, we discovered that the steric bulk of both the substrate and the phosphine ligand play an important role in promoting the desired reactivity. Mechanistic insight has been gained through combined experimental and computational studies, which implicate a palladium-catalyzed stereoisomerization in both of these transformations. Under certain conditions, we demonstrate that highly stereoselective trans-additions to alkynes can be achieved, which illustrates that specific substrate/catalyst combinations can override the inherent cis-selectivity in carbometallations. In the fourth chapter, a formal palladium(II)-catalyzed alkyne chlorocarbamoylation reaction is presented, which provides access to medicinally relevant methylene oxindole scaffolds. In contrast to the analogous protocol using palladium(0) catalysts, the reaction is initiated by an alkyne chloropalladation step, followed by intramolecular cross-coupling with a carbamoyl chloride. Experimental and computational studies provide insight into the mechanism of this reaction.

Ruthenium-Catalyzed [2+2] Cycloaddition Reactions Between a 3-Aza-2-oxabicyclo[2.2.1]hept-5-ene and Unsymmetrical Alkynes

Ruthenium-Catalyzed [2+2] Cycloaddition Reactions Between a 3-Aza-2-oxabicyclo[2.2.1]hept-5-ene and Unsymmetrical Alkynes PDF Author: Robin Durham
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Languages : en
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Inter- and Intramolecular Ring-Opening Reactions of Oxabicyclic Substrates

Inter- and Intramolecular Ring-Opening Reactions of Oxabicyclic Substrates PDF Author: Christopher Wicks
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Languages : en
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Oxabenzonorbornadiene (OBD) and derivatives thereof have become key substrates of interest within synthetic organic chemistry and natural product synthesis as they enable the formation of multiple stereocenters in a single transformation. The present work expands on previous studies to investigate various intramolecular transformations, and regiochemical implications regarding ring-opening reactions of asymmetric oxabicyclic alkenes. Acid-catalyzed intramolecular ring-opening reactions of cyclopropanated oxabenzonorbornadiene (CPOBD) derivatives were investigated to afford novel medium-sized ring systems in moderate to good yields and good to excellent regioselectivity. Similarly, a Ni catalyzed intramolecular ring-opening reaction of alkyl halide tethered OBD compounds was optimized, thus generating a naphthalene derivative in excellent yields. Lastly, iridium-catalyzed ring-opening reactions of unsymmetrical C1-substituted OBD derivatives is presented using alcohols and water as nucleophiles which allows for the selective synthesis of previously inaccessible substrates.

Transition Metal Catalyzed Ring-opening Reactions of Unsymmetrical Oxabicyclic Alkenes

Transition Metal Catalyzed Ring-opening Reactions of Unsymmetrical Oxabicyclic Alkenes PDF Author: Raheem Mohammed Abdul
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Languages : en
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Inventing Reactions

Inventing Reactions PDF Author: Lukas J. Gooßen
Publisher: Springer
ISBN: 3642342868
Category : Science
Languages : en
Pages : 345

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Barry Trost: Transition metal catalyzed allylic alkylation.- Jeffrey W. Bode: Reinventing Amide Bond Formation.- Naoto Chatani and Mamoru Tobisu: Catalytic Transformations Involving the Cleavage of C-OMe Bonds.- Gregory L. Beutner and Scott E. Denmark: The Interplay of Invention, Observation and Discovery in the Development of Lewis Base Activation of Lewis Acids for Catalytic Enantioselective Synthesis.- David R. Stuart and Keith Fagnou: The Discovery and Development of a Palladium(II)-Catalyzed Oxidative Cross-Coupling of Two Unactivated Arenes.- Lukas Gooßen and Käthe Gooßen: Decarboxylative Cross-Coupling Reactions.- A. Stephen K. Hashmi: Gold-Catalyzed Organic Reactions.- Ben List: Developing Catalytic Asymmetric Acetalizations.- Steven M. Bischof, Brian G. Hashiguchi, Michael M. Konnick, and Roy A. Periana: The De NovoDesign of CH Bond Hydroxylation Catalysts.- Benoit Cardinal-David, Karl A. Scheidt: Carbene Catalysis: Beyond the Benzoin and Stetter Reactions.- Kenso Soai and Tsuneomi Kawasaki: Asymmetric autocatalysis of pyrimidyl alkanol.- Douglas C. Behenna and Brian M. Stoltz: Natural Products as Inspiration for Reaction Development: Catalytic Enantioselective Decarboxylative Reactions of Prochiral Enolate Equivalents. Hisashi Yamamoto: Acid Catalysis in Organic Synthesis.

Nickel-catalyzed Asymmetric Reductive Ring Opening of Oxabicyclic Alkenes

Nickel-catalyzed Asymmetric Reductive Ring Opening of Oxabicyclic Alkenes PDF Author:
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Languages : en
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Chemical Abstracts

Chemical Abstracts PDF Author:
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Category : Chemistry
Languages : en
Pages : 2762

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The Pauson-Khand Reaction

The Pauson-Khand Reaction PDF Author: Ramon Rios Torres
Publisher: John Wiley & Sons
ISBN: 1118308638
Category : Science
Languages : en
Pages : 422

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The Pauson-Khand reaction is an important reaction in the field of organic chemistry. It involves the transition-metal catalysed cycloaddition of an alkyne, an alkene and carbon monoxide, to produce cyclopentenones. The importance of this reaction originates from its high value in transforming simple components into the synthetically useful cyclopentenone unit, in which a high degree of molecular complexity can be achieved in a single step, with impressive stereochemical and regiochemical control. The Pauson-Khand Reaction investigates the nature and many variations of this reaction. Topics covered include: the mechanisms of Pauson‐Khand-type reactions non chiral intramolecular and intermolecular versions of Pauson‐Khand reactions asymmetric Pauson‐Khand reaction using chiral auxiliaries the enantioselective Pauson‐Khand reaction Pauson‐Khand reactions catalysed by metals other than cobalt unconventional Pauson‐Khand reactions the Pauson‐Khand reaction in total synthesis Presenting a comprehensive overview of this fundamental reaction, The Pauson-Khand Reaction will find a place on the bookshelves of any organic or organometallic chemist.

Modern Aryne Chemistry

Modern Aryne Chemistry PDF Author: Akkattu T. Biju
Publisher: John Wiley & Sons
ISBN: 3527346465
Category : Science
Languages : en
Pages : 530

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A groundbreaking book to offer a a comprehensive account of important reactions involving arynes Modern Aryne Chemistry is the first book on the market to offer a conceptual framework to the reactions related to arynes. It also provides a systematic introduction to the cycloaddition reactions, insertion reactions and transition-metal-catalyzed transformations of arynes. The author, a noted expert on the topic, highlights a novel strategy for carbon-carbon and carbon-heteroatom bond construction using arynes. The book reveiws the recent use of aryne chemistry for the development of new multicomponent reactions. New advances in this area has shown rapid emergence of a new class of reactions classified under rearrangement reactions. The author also includes information on aryne methods that have been employed for the synthesis of several natural products. The simplicity and sophistication of the synthetic strategy using arynes can serve as a springboard for organic chemists to explore new possibilities and imagine applications of the concept of arynes. This important book: Presents a one-of-kind comprehensive guide to arynes reactions Offers a proven approach to the synthesis of natural product and polymers Reviews the most recent developments in the carbon-carbon and carbon-heteroatom bond-forming reactions involving arynes Written for organic, pharmaceutical, medicinal, natural products, and catalytic Chemists, Modern Aryne Chemistry offers a comprehensive review of the fundamentals of reactions related to arynes and the most recent developments in the field.