Synthesis of (2S,3S)-beta-(trifluoromethyl)-alpha,beta-diamino acid by Mannich addition of glycine Schiff base Ni(II) complexes to N-tert-butylsulfinyl-3,3,3-trifluoroacetaldimine

A convenient access to (25,3S)-beta-(trifluoromethyl)-alpha,beta-diamino acid is reported by using highly diastereoselective Mannich addition reactions of either chiral or achiral Ni(II) complexes derived from glycine Schiff bases to a chiral sulfinimine, N-tert-butylsulfinyl-3,3,3-trifluoroacetaldimine. Disassembly of the resultant Ni(II) complexes affords the target amino acid which was, for the first time, isolated in enantiomerically pure form and fully characterized. (C) 2014 Elsevier B.V. All rights reserved.