Chiral Phosphoric Acid-Catalyzed Kinetic Resolution via Amide Bond Formation.

We describe the kinetic resolution of a readily available 2-pyridyl ester via an amide bond formation catalyzed by a chiral Brønsted acid. A chiral phosphoric acid bearing a 2,4,6-trimethyl-3,5-dinitrophenyl group at the 3,3'-position enabled this transformation with high selectivities. We also found that the addition of Lewis acid increased both the reactivity and selectivity in the substrate with a methoxy group.