Chiral hydrazones, synthesized from (S)-1-amino-2-methoxymethylindoline and aliphatic aldehydes, reacted with trimethylsilyl cyanide in the presence of diethylaluminium chloride in CH2Cl2 at -78 degrees C to give chiral alpha-hydrazinonitriles with high diastereoselectivity (up to 96% de). Copyright (C) 1996 Elsevier Science Ltd.