Ene reaction

About: Ene reaction is a research topic. Over the lifetime, 10748 publications have been published within this topic receiving 125582 citations.

Thiol–Ene Click Chemistry

Abstract: Following Sharpless' visionary characterization of several idealized reactions as click reactions, the materials science and synthetic chemistry communities have pursued numerous routes toward the identification and implementation of these click reactions. Herein, we review the radical-mediated thiol-ene reaction as one such click reaction. This reaction has all the desirable features of a click reaction, being highly efficient, simple to execute with no side products and proceeding rapidly to high yield. Further, the thiol-ene reaction is most frequently photoinitiated, particularly for photopolymerizations resulting in highly uniform polymer networks, promoting unique capabilities related to spatial and temporal control of the click reaction. The reaction mechanism and its implementation in various synthetic methodologies, biofunctionalization, surface and polymer modification, and polymerization are all reviewed.

Chiral bis(oxazoline) copper(II) complexes: versatile catalysts for enantioselective cycloaddition, Aldol, Michael, and carbonyl ene reactions.

Abstract: A bis(oxazoline) (box) copper(II) complex and its hydrated counterpart (1 and 2) function as enantioselective Lewis acid catalysts for carbocyclic and hetero Diels−Alder, aldol, Michael, ene, and amination reactions with substrates capable of chelation through six- and five-membered rings. X-ray crystallography of the chiral complexes reveals a propensity for the formation of distorted square planar or square pyramidal geometries. The sense of asymmetric induction is identical for all the processes catalyzed by [Cu((S,S)-t-Bu-box)](X)2 complexes 1 and 2 (X = OTf and SbF) resulting from the intervention of a distorted square planar catalyst-substrate binary complex. These catalyzed processes exhibit excellent temperature−selectivity profiles. Reactions catalyzed by [Cu(S,S-Ph-pybox)](SbF6)2 and their derived chelation complexes are also discussed.

Robust, Efficient, and Orthogonal Synthesis of Dendrimers via Thiol-ene “Click” Chemistry

Abstract: Dendrimers up to the fourth generation were successfully prepared via the divergent growth strategy using a combination of thiol-ene “click” chemistry and traditional esterification reactions. The thiol-ene reactions were conducted under solvent-free, ambient conditions at room temperature by irradiating with UV light. The fourth-generation dendrimers were subsequently functionalized with carboxylic acid, pyrene, and Fmoc-protected cysteine moieties via thiol-ene reactions.

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.

Cycloaddition reactions in organic synthesis

Abstract: Section headings and selected subheadings: The Diels-Alder Reaction - General Aspects. The dienophile. Hetero-dienophiles - aldehydes, thiocarbonyl compounds, N-sulphinylsulphonamides, imines, nitroso compounds. The diene. ortho-Quinodimethanes. Heterodienes. Reactions in water. Reactions under high pressure. Catalysis by Lewis acids. Regiochemistry. Stereochemistry. Asymmetric reactions. Retro reactions. Intermolecular Diels-Alder Reactions. Stereoselectivity. Hetero-substituted dienes and dienophiles. With alkoxy- and silyloxy-dienes. alphabeta-Unsaturated aldehydes as dienes. Imines as dienophiles. Nitroso compounds as dienophiles-synthesis of 4-amino-alcohols. N-Sulphinylsulphonamides-synthesis of vicinal amino-alcohols. Synthesis of benzene derivatives. Synthesis of quinones. Retro reactions. Intramolecular Diels-Alder Reactions. Stereoselectivity. Diastereoselection. Synthesis of terpenoids. Synthesis of alkaloids. Nitroso compounds. Miscellaneous [4+2] Cycloadditions. Allyl anions and allyl cations. Oxyallyl cations. Pentadienyl cations. Cycloadditions with trimethylenemethane. meta-Photocycloaddition to benzene derivatives. Cobalt-catalysed trimerisation of acetylenes. [4+4] cycloaddition of 1,3-dienes. The Ene Reaction. Hetero-ene reactions. Intramolecular ene reactions. Diastereoselection. Magnesio-ene reaction. 1,3-Dipolar Cycloaddition Reactions. Stereoselectivity. Azomethine ylides. Nitrile oxides. Azides, azomethine imines and diazoalkanes. [2+2] Cycloaddition Reactions. Ketenes. Ketene-imminium salts. Photocycloaddition to enones. De Mayo reaction. Copper-catalysed photocycloaddition of hepta-1,6-dienols. Paterno-Buchi reaction. Index.