Asymmetric Phase-Transfer Alkylation of Readily Available Aryl Aldehyde Schiff Bases of Amino Acid Ethyl Esters.

Asymmetric phase-transfer alkylation of the N -(arylmethylene)-α-alkylamino acid ethyl esters and N -(arylmethylene)glycine ethyl esters was found to be catalyzed by the ( R )- or ( S )-Simplified Maruoka Catalyst with high efficiency and excellent enantioselectivity. This approach was successfully applied to the enantioselective formal synthesis of the angiotensin II type 2 receptor (AT2R) antagonists Olodanrigan and LX9211, and the practical aspect is demonstrated by the kilogram-scale synthesis of a key intermediate for the synthesis of LX9211.