Access to chiral α-methyl-α-aryl carboxylic acids via phosphoric acid-catalyzed kinetic resolution of biaryl oxazepines

Abstract

We disclose herein a chiral phosphoric acid-catalyzed kinetic resolution of racemic biaryl oxazepines with alcohols, giving a series of biaryl oxazepines and imidate products bearing a chiral center in good yields and enantioselectivities. The racemic biaryl oxazepine substrates could be readily synthesized from racemic carboxylic acids. Hydrolysis of the chiral imidate products afforded α-methyl-α-aryl carboxylic acids in high yields and enantioselectivities.