STEREOSELECTIVE SUBSTITUTION IN 2-BROMO AMIDES IN THE PRESENCE OF AG+OR AG2O

Bromine displacement by a primary, secondary, or tertiary amine, or me thanol, in chiral nonracemic (S)-2-bromopropanamides 1 occurs with hig h yields and stereo selectivity. Soluble Ag+ promotes inversion, and s olid Ag2O promotes retention of configuration. However, in the case of Et(3)N, Ag+ promotes retention. With the hindered 2-bromo-2-methylbut anamide 5, the displacement by a primary or secondary amine or methano l occurs only in the presence of Ag2O, possibly with retention of conf iguration.