Catalytic asymmetric synthesis of axially chiral 2-amino-1,1′-biaryl compounds by phase-transfer-catalyzed kinetic resolution and desymmetrization

Abstract

An efficient methodology for kinetic resolution of axially chiral 2-amino-1,1′-biaryl compounds as useful chiral building blocks was developed by means of binaphthyl-modified chiral quaternary ammonium salt-catalyzed N-allylations under phase-transfer conditions. The catalyst structure and reaction conditions were carefully optimized to achieve the highly selective kinetic resolutions. Various types of 2-amino-1,1′-biaryls were submitted to the kinetic resolution under the phase-transfer conditions to resolve the enantiomers with high selectivities. The synthetic utility of this method could be extended to the asymmetric desymmetrization of diamino biaryl compounds to obtain the corresponding axially chiral biaryls with high enantioselectivities.