Asymmetric Strecker Reaction with Chiral Amines: a Catalyst-Free Protocol Using Acetone Cyanohydrin in Water

The synthesis of a series of new chiral alpha-aminonitriles was achieved in a diastereoselective Strecker reaction in a one-pot procedure with aldehydes, enantiopure amines, and acetone cyanohydrin in water. Primary and secondary amines derived from L-alpha-amino acids were used as sources of chirality. The reactions proceeded efficiently without any catalyst at room temperature. The diastereoselectivity of the process, and the configurational stability of new chiral alpha-aminonitriles were investigated. The identification of labile intermediates by NMR analysis, and a proposed mechanism and a model for the asymmetric induction are reported. The chemical transformation of proline-derived chiral alpha-amino-nitriles into chiral amino-diacids, aminols, and amides is reported.