Sigmatropic reaction

About: Sigmatropic reaction is a research topic. Over the lifetime, 4586 publications have been published within this topic receiving 66095 citations.

Selective molecular recognition, C-H bond activation, and catalysis in nanoscale reaction vessels

Abstract: Supramolecular chemistry represents a way to mimic enzyme reactivity by using specially designed container molecules. We have shown that a chiral self-assembled M4L6 supramolecular tetrahedron can encapsulate a variety of cationic guests with varying degrees of stereoselectivity. Reactive iridium guests can be encapsulated, and the C−H bond activation of aldehydes occurs with the host cavity controlling the ability of substrates to interact with the metal center based upon size and shape. In addition, the host container can act as a catalyst by itself. By restricting reaction space and preorganizing the substrates into reactive conformations, it accelerates the sigmatropic rearrangement of enammonium cations.

Modern Allene Chemistry

Abstract: Volume 1.I Synthesis of Allenes.1 Synthesis of Allenes by Isomerization Reactions (A. Stephen K. Hashmi).1.1 Introduction.1.2 Prototropic Rearrangements and Related Reactions of Alkynes.1.3 Sigmatropic Rearrangements.1.4 Rearrangements of Other Systems with at Least Two p-Bonds.1.5 Retro-Ene Reactions.1.6 Electrocyclic Ring Openings.1.7 Intramolecular Conjugate Additions.1.8 Complex Reactions and Rearrangements.1.9 Conclusion.2 Metal-Mediated Synthesis of Allenes (Anja Hoffmann-Roder and Norbert Krause).2.1 Introduction.2.2 Copper-Mediated Synthesis of Allenes.2.3 Lithium-, Magnesium- and Zinc-Mediated Synthesis of Allenes.2.4 Aluminum- and Indium-Mediated Synthesis of Allenes.2.5 Titanium- and Samarium-Mediated Synthesis of Allenes.2.6 Conclusion.3 Transition Metal-Catalyzed Synthesis of Allenes (Masamichi Ogasawara and Tamio Hayashi).3.1 Introduction.3.2 Formation of Allenes by Substitution Reactions.3.3 Formation of Allenes by Addition Reactions.3.4 Formation of Allenes by Elimination Reactions.3.5 Other Miscellaneous Methods of Preparing Allenes.3.6 Formation of 1,2,3-Butatrienes.3.7 Conclusion.4 Enantioselective Synthesis of Allenes (Hiroaki Ohno, Yasuo Nagaoka, and Kiyoshi Tomioka).4.1 Introduction.4.2 Chirality Transfer from Propargylic Compounds.4.3 Elimination Reactions of Chiral Allylic Compounds.4.4 Synthesis of Allenes Using Chiral Reagents.4.5 Direct Asymmetric Synthesis of Allenes Using an External Chiral Catalyst.4.6 Synthesis of Allenes Using Internal Chiral Auxiliaries.4.7 Kinetic Resolution.4.8 Conclusion.II Special Classes of Allenes.5 Allenic Hydrocarbons - Preparation and Use in Organic Synthesis (Henning Hopf).5.1 Introduction.5.2 Allenic Hydrocarbons from Simple Building Blocks.5.3 Preparation of Allenic Hydrocarbons.5.4 Allenic Hydrocarbons as Reaction Intermediates.5.5 Why Allenic Hydrocarbons Are of Interest in Preparative Organic Chemistry.6 Cyclic Allenes Up to Seven-Membered Rings (Manfred Christl).6.1 Introduction.6.2 Three-, Four- and Five-Membered Rings.6.3 Six-Membered Rings.6.4 Seven-Membered Rings.7 Acceptor-Substituted Allenes (Klaus Banert and Jens Lehmann).7.1 Introduction.7.2 Synthesis of Acceptor-Substituted Allenes.7.3 Reactions of Acceptor-Substituted Allenes.7.4 Conclusion.8 Donor-Substituted Allenes (Reinhold Zimmer and Hans-Ulrich Reissig).8.1 Introduction.8.2 O-Substituted Allenes.8.3 N-Substituted Allenes.8.4 S- and Se-Substituted Allenes.8.5 Conclusion.9 Synthesis and Reactions of Allenylmetal Compounds (James A. Marshall, Benjamin W. Gung, and Melissa L. Grachan).9.1 Introduction.9.2 Allenyllithium Reagents.9.2.1 Structure.9.3 Allenylcopper Reagents.9.4 Allenylmagnesium Halides.9.5 Allenylboron Reagents.9.6 Allenyltitanium Reagents.9.7 Allenylsilanes.9.8 Allenylstannanes.9.9 Allenylpalladium Reagents.9.10 Allenylzinc Reagents.9.11 Allenylindium Reagents.9.12 Miscellaneous Allenylmetal Reagents.Volume 2.III Reactions of Allenes.10 Ionic Additions to Allenes (Shengming Ma).10.1 Unfunctionalized Allenes.10.2 Allenylsilanes.10.3 1,2-Allenyl Sulfides.10.4 1,2-Allenyl Ethers.10.5 1,2-Allenyl Halides.10.6 Phosphorus-Containing Allenes.10.7 1,2-Allenyl Sulfoxides.10.8 1,2-Allenyl Sulfones.10.9 Allenylamines.10.10 2,3-Allenols.10.11 1,2-Allenic Ketones.10.12 2,3-Allenoic Acids and 2,3-Allenoates.10.13 2,3-Allenamides.10.14 2,3-Allenyl Nitriles.11 Fundamentals and Application of Free Radical Addition to Allenes (Jens Hartung and Thomas Kopf).11.1 Introduction.11.2 Basic Principles.11.3 Intermolecular Additions of Alkyl Radicals to Allenes,11.4 Intramolecular Radical Additions to Cumulated Double Bonds,11.5 Summary and Perspectives.12 Cycloadditions of Allenes (Masahiro Murakami and Takanori Matsuda).12.1 Introduction.12.2 [2 + 2]-Cycloaddition of Allenes.12.3 [3 + 2]-Cycloaddition of Allenes.12.4 [4 + 2]-Cycloaddition of Allenes.12.5 Vinylallenes and Bisallenes.12.6 Miscellaneous Cycloaddition Reaction of Allenes.13 Cyclizations of Allenes (Marcus A. Tius).13.1 Introduction.13.2 Nazarov and Related Reactions.13.3 Annulations Making Use of Trialkylsilyl Allenes (Danheiser Reactions).13.4 Allene Cyclizations Leading to Dihydrofurans, Furans, Pyrrolines and Pyrroles.13.5 Ene Reactions of Allenes.13.6 Miscellaneous Cyclizations of Allenes.13.7 Conclusion.14 Transition Metal-Catalyzed Cross-Couplings of Allenes (Reinhold Zimmer and Hans-Ulrich Reissig).14.1 Introduction.14.2 Cross-Coupling Reactions of Allenes Producing Compounds with an Intact 1,2-Diene Moiety.14.3 Cross-Coupling Reactions of Allenes at the Central Position.14.4 Synthesis of Alkynes.14.5 Miscellaneous Reactions.14.6 Conclusion.15 Transition Metal-Catalyzed Cycloisomerizations of Allenes (A. Stephen K. Hashmi).15.1 Introduction.15.2 Alcohols as Nucleophiles.15.3 Allenyl Ketones.15.4 Allenic Carboxylic Acids.15.5 Amines as Nucleophiles.15.6 Amides as Nucleophiles.15.7 Sulfonamides as Nucleophiles.15.8 Imines and Related Groups as Nucleophiles.15.9 Oximes as Nucleophiles.15.10 Phosphonic Acids.15.11 Activated C-H Bonds.15.12 Reaction with Other C-C Multiple Bonds.15.13 Conclusion.16 Transition Metal-Catalyzed Addition/Cycloaddition of Allenes (Tadakatsu Mandai).16.1 Introduction.16.2 Reactions via Carbopalladation.16.3 Carbonylation.16.4 Pauson-Khand Reactions.16.5 Carbon-Metal Bond Formation.16.6 Allenic Alder Ene Reaction and Cycloisomerization.16.7 Homo- and Cross-Coupling Reactions.16.8 Miscellaneous Reactions.16.9 Conclusions.17 Oxidation of Allenes (Attila Horvath and Jan-E. Backvall).17.1 Introduction.17.2 Palladium(II)-Catalyzed 1,2-Oxidations.17.3 Catalytic Osmylation.17.4 Ruthenium-Catalyzed Oxidation.17.5 Epoxidation.17.6 Oxidation by Sulfur.IV Applications.18 Allenic Natural Products and Pharmaceuticals (Norbert Krause and Anja Hoffmann-Roder)18.1 Introduction.18.2 Allenic Natural Products.18.3 Pharmacologically Active Allenes.18.4 Conclusion.19 Allenes in Natural Product Synthesis (Kay M. Brummond and Hongfeng Chen).19.1 Introduction.19.2 Cycloaddition Reactions.19.3 Transition Metal-Catalyzed Cycloadditions.19.4 Transition Metal-Promoted Heterocyclizations.19.5 Acid-Catalyzed Rearrangements.19.6 Allenyl Organometallic Intermediates.19.7 Allenoates.19.8 Imino-Ene Reactions.19.9 Oxidation of Allenes.19.10 Electrocyclizations.19.11 Miscellaneous.20 Enyne-Allenes (Kung K. Wang).20.1 Introduction.20.2 Synthesis and Cyclization.20.3 Cascade Radical Cyclizations of Biradicals Generated from Enyne-Allenes.20.4 Synthesis of a C44H26 Hydrocarbon Having a Carbon Framework Represented on the Surface of C60.20.5 Synthesis of Twisted 4,5-Diarylphenanthrenes.20.6 Synthesis of the Benzo[b]fluorene Core of the Kinamycins.Subject Index.

Around and beyond Cram's Rule.

Abstract: C. Pericyclic Reactions 1210 1. [4+2]-Cycloadditions 1210 2. [3+2]-Cycloadditions 1211 3. [2+2]-Cycloadditions 1212 D. Sigmatropic Rearrangements 1212 1. Claisen Rearrangement 1212 2. [2,3]-Wittig Rearrangements 1213 E. Radical Reactions 1214 IV. 1,3-Induction 1215 A. Chelation-Controlled 1,3-Induction 1215 B. Nonchelation-Controlled 1,3-Induction 1216 1. Cram−Reetz Model 1216 2. Evans Model 1216 C. 1,4-Induction 1219 V. Conclusion 1219 VI. References 1221