Enantioselective strecker reaction of phosphinoyl ketoimines catalyzed by in situ prepared chiral N,N'-dioxides.

The enantioselective Strecker reaction of N-diphenylphosphinoyl ketoimines has been achieved by use of in situ prepared chiral N,N'-dioxide catalyst from l-piperidinamide 3f and m-chloroperoxybenzoic acid (m-CPBA). Excellent yields (up to 99%) and high enantioselectivities (up to 92% ee) were obtained. In particular, in situ prepared catalyst with readily available chiral material made the procedure more convenient. Moreover, the l-piperidinamide 3f-derived N,N'-dioxide 9 could be recycled and reused at least five times without any loss of either catalytic activity or enantioselectivity.