Acetylene systems present a new route to cyclic compounds as an alternative to more traditional methods employed in classical organic chemistry. The synthesis of cyclic structures based on acetylene systems has important applications in the formation of nanostructures, naturally occurring compounds and chemosensory materials for the design of nonlinear optics, electronic and photonic devices.
Alkynes in Cycloadditions presents a modern review of regioselective synthesis of aromatic and non-aromatic carbocyclic and heterocyclic ring systems based primarily on [2+2+2] and [4+2] cycloadditions, and other reactions of acetylenic units including enediynes and enyne-allenes.
Topics covered include:
- New strategies for the formation of aromatic and polynuclear hydrocarbons based on (Z)-hex-3-en-1,5-diyne and (Z)-hepta-1,2,4-triene-6-yne blocks.
- One-step synthesis of benzene derivatives, β-substituted naphthalenes and acenes by the cycloaromatization of enediynes and enyne-allenes by Bergman, Myers-Saito and Shmittel.
- Mechanisms of cycloaromatization resulting in the formation of fulvene and indene systems.
- Heterocyclization involving enyne-carbodiimides.
- New achievements in classical cycloaddition reactions such as the Diels-Alder condensation with acetylenic dienophiles and [2+2] cycloadditions with acetylene components
Alkynes in Cycloadditions presents a comprehensive summary of the literature on methods for the synthesis of ring systems from acetylenes for academic researchers working in the fields of organic synthesis, physical organic chemistry, organometallic chemistry, catalysis, materials science, nanomaterials and biochemistry.
1 Introduction 1
2 Regioselective Syntheses of Polysubstituted Benzenes Catalyzed by Transition Metal Complexes 5
2.1 Reactions of [2+2+2] Cycloaddition of Acetylene Units 5
2.2 Stereochemical Aspect of The Problem of Intermolecular Reactions of Diynes with Monoalkynes 18
2.3 Heteroatom Bound to the Triple Bond 28
2.4 Heterohelicens. Asymmetric Syntheses 34
2.5 Aromatic Rings with Boron and Silicon Substituents 38
2.6 [2+2+2] Cycloaddition Reactions of 1-Alkynylphosphines and Their Derivatives 40
2.7 Intramolecular [2+2+2] Cycloaddition of Diynes to Alkenes 45
2.8 Polysubstituted Benzenes. Reactions of [4+2] Cycloaddition and Other Approaches 53
2.9 Combined Reactions 63
2.10 Construction of Polycyclic Systems 71
3 Radical Cycloaromatization of Systems Containing (Z)-3-hexene-1,5-diynes and (Z)-1,2,4-heptatrien-6-ynes and Related Heteroatomic Blocks 107
3.1 The Historical Aspect of the Chemistry of Enediynes, Enyne-Allenes and Enyne-Cumulenes 107
3.2 Routes to the Cycloaromatization of Enediyne and Enyne-Allene Systems. Bergman and Myers–Saito Cyclization 113
3.3 Cycloaromatization by C1–C5, C2–C7 and C2–C6 (Myers–Saito and Schmittel) Routes to Indeno-Fused Structures 135
3.4 External Initiation of the Enediyne Cycloaromatization 157
3.5 Features of Cycloaromatization of Heteroatomic Enediynes 179
3.6 Cycloaromatization of Hetero-Systems 223
4 Selected Cycloaddition and Heterocyclization Reactions with Unusual Acetylenic and Allenic Starting Compounds 233
4.1 Cycloaddition and Heterocyclization Reactions of Acetylenic Compounds with Electron-Withdrawing Substituents 233
4.2 Diels–Alder [4+2] Cycloaddition: Acetylenes as Dienophiles 235
4.3 Formation of Cyclobutene Derivatives by [2+2]-Cycloaddition 237
4.4 [2+2] Cyclization of Some 1,3-Butadienes Produced from Acetylenic Alcohols of Propargyl Type 243
4.5 Heterocyclization of Electron-Deficient Acetylenes with Nucleophilic Reagents 245
5 Concluding Remarks 249