Chiral Lewis Acids in Catalytic Asymmetric Reactions

Abstract

This review examines the recent advances in the use of chiral Lewis acids, usually generated in situ from a Lewis acid and a chiral auxiliary, in the Diels-Alder reaction, the ene reaction, the hydrocyanation of aldehydes, the ring-opening of epoxides and various miscellaneous reactions. Structural studies of the complex formed between carbonyl compounds and Lewis acids are also reported. The Sharpless epoxidation is not covered by this review. 1. Introduction 2. Asymmetric Diels-Alder Reactions 2.1. Chiral Titanium Reagents 2.2. Chiral Aluminum Reagents 2.3. Chiral Boron Reagents 2.4. Chiral Ruthenium Reagents 3. Asymmetric [2+2] Cycloaddition Reactions 4. Asymmetric Ene Reaction 5. Asymmetric Hydrocyanation of Aldehydes 6. Asymmetric Ring Opening of Epoxides 7. Miscellaneous Asymmetric Reactions 8. Structural Studies on the Complexes of Carbonyl Compounds and Lewis Acids