Reversal of diastereoselection in the addition of Grignard reagents to chiral 2-pyridyl tert-butyl (Ellman) sulfinimines

Addition of Grignard reagents to chiral tert-butyl sulfinimines derived from pyridine 2-carboxaldehyde affords protected 2-pyridyl amines in high yields and diastereoselectivities. The sense of chiral induction is opposite to that predicted via a chelation-controlled transition state. (C) 2004 Published by Elsevier Ltd.