Die präparative Chemie der Cyclobutendione; II. Reaktionen von Alkyl-, Alkenyl- und Arylcyclobutendionen

In Part I of the review*, the syntheses of cyclobutenediones from open-chain precursors were described. The following Part II deals with the reactivity and transformation of alkyl-, alkenyl-, and arylcyclobutenediones. 1. Substitution Reactions 1.1. Hydrogen/Halogen Exchange 1.2. Reaction with Water and Alcohols 1.3. Reactions with Amines and Hydrazines 1.4. Friedel-Crafts Reactions of Halocyclobutenediones with Arenes 1.5. Reaction with Electron-rich Alkenes 1.6. Reaction with Carbanions 1.7. Reaction with Ylides 1.8. Reaction with Hydrogen Sulfide and Mercapto Compounds 1.9. Reaction with Thiocyanate Ion 1.10. Unusual Substitution Reactions 1.11. Side-Chain Substitution Reactions of Alkylcyclobutenediones 2. Condensation and Related Carbonyl Reactions 2.1. Reaction of Hydroxy-and Mercaptocyclobutenediones with Amines 2.2. Formation of Oximes and Hydrazones 2.3. Reaction with Phosphorus(V) Sulfide 2.4. Carbonyl Olefination with Alkylidenephosphoranes 3. Addition Reactions 3.1. 1,4-Additions 3.1.1. Addition of Sulfinic Acids, Tosyl Hydrazide, and Amidrazones 3.1.2. Addition of Mercapto Compounds 3.1.3. Addition of Arenes 3.1.4. Addition of Carbanions 3.1.5. Addition of Aroyl Halides 3.1.6. Addition of Trialkyl Phosphite 3.2. Addition Reactions of the Carbonyl Groups 3.3. Cycloaddition Reactions 4. Ring-Cleavage Reactions 5. Ring-Enlargement Reactions