Application of sulfonyl chlorides and chiral amines in the efficient synthesis of nonracemic sulfinamides

A simple protocol that allows the preparation of separable epimeric sulfinamides from chiral amines and sulfonyl chlorides reduced in situ with triphenylphosphine in the presence of KOH is described. Using this method, tosyl chloride and nosyl chloride were successfully reacted with α-substituted primary amines to give five diastereomeric pairs, in certain cases accompanied by a small amount of the corresponding sulfonamide. Enantiopure products were isolated by column chromatography. The obtained enantiomerically pure sulfinamides were tested as organocatalysts in the asymmetric epoxide ring opening.