F. Dangeli et al., STEREOSELECTIVE SUBSTITUTION IN 2-BROMO AMIDES IN THE PRESENCE OF AG+OR AG2O, Journal of organic chemistry, 60(13), 1995, pp. 4013-4016
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.