A General Catalyst for the Asymmetric Strecker Reaction

From a parallel library of 70 compounds, the salicylidene imine derivative 1 was identified as a remarkably enantioselective and general catalyst for the Strecker reaction with a variety of aromatic and aliphatic aldimines. While the soluble catalyst affords slightly higher ee values in most reactions, the use of its polystyrene-resin-bound analogue allows facile isolation of the Strecker products in nearly quantitative yield, and it can be recycled over ten times without loss of activity or selectivity.