Kinetic resolution of α-bromophenylacetamides using quinine or Cinchona alkaloid salts

The kinetic resolution of racemic α-bromophenylacetamides 1 was achieved in the presence of benzenethiolate and Cinchona alkaloid salts as phase-transfer catalysts or benzenethiol and quinine, yielding (S)-enantioenriched α-sulfanylated products. The observed stereoselection was rationalized on the basis of the best fitting of 1 and the resolving agent in the ternary complexes.

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2-(S)-Phenylsulfanyl-N,N-diphenylphenylacetamideC26H21NOSEe 30% (HPLC)[α]D25=+12 (c 3.9, acetone)Source of chirality: (S)-(+)-mandelic acidAbsolute configuration: (2S)