Stereoselective Substitution in 2-Bromo Amides in the Presence of Ag+ or Ag2O
摘要:
Bromine displacement by a primary, secondary, or tertiary amine, or methanol, in chiral nonracemic (S)-2-bromopropanamides 1 occurs with high yields and stereo selectivity. Soluble Ag+ promotes inversion, and solid Ag2O promotes retention of configuration. However, in the case of Et(3)N, Ag+ promotes retention. With the hindered 2-bromo-2-methylbutanamide 5, the displacement by a primary or secondary amine or methanol occurs only in the presence of Ag2O, possibly with retention of configuration.
Synthesis of new optically active α-alkoxypropionanilides
作者:M.M. El-abadelah
DOI:10.1016/0040-4020(73)80014-6
日期:1973.1
Two promising routes towards synthesis of the hitherto unknown α-alkoxypropionanilides were explored with success. As expected, facile displacement of the bromide in l(−)α-bromopropionanilide by alkoxide lead to inversion of configuration with considerable racemization, whereas substitution of the chloride in l(−) α-alkoxypropionyl chloride by arylamine proceeded with little or no racemization. α-