Stereoselective Substitution in 2-Bromo Amides in the Presence of Ag+ or Ag2O

Abstract

Bromine displacement by a primary, secondary, or tertiary amine, or methanol, in chiral nonracemic
\n(S)-2-bromopropanamides 1 occurs with high yields and stereoselectivity. Soluble Ag+ promotes
\ninversion, and solid AgzO promotes retention of configuration. However, in the case of Et3N, Ag+
\npromotes retention. With the hindered 2-bromo-2-methylbutanamid5e, the displacement by a
\nprimary or secondary amine or methanol occurs only in the presence of Ag20, possibly with retention
\nof configuration.