Kinetic Resolution of α-Amino Acid Derivatives

Significance

A new method for the kinetic resolution of α-trifluoroacetamido N-acyl oxazolidine­thiones 1 using 5-10% of chiral O-nucleophilic acyl transfer catalyst 2 is presented. The selectivity-determining step of the reaction proceeds through the attack of the hydroxyl group of the catalyst onto the active ester of 1 with general base catalysis from the amine function of the catalyst. Attack of methanol on the formed acyl-catalyst intermediate provides methyl ester 4 and regenerates catalyst 2. This method works in excellent yields and with s-factors ranging from 20 to 86 with a variety of cyclic and acyclic substrates and affords materials of high enantiomeric ratios, which can be directly used as substrates in peptide coupling reactions.