Highly enantioselective iridium-catalyzed hydrogenation of quinoline derivatives using chiral phosphinite H8-BINAPO

The chiral diphosphinite H8-BINAPO derived from H8-BINOL has been used in the Ir-catalyzed asymmetric hydrogenation of quinolines, and high enantioselectivity (up to 97% ee) was obtained. Immobilization of the iridium catalyst in poly(ethylene glycol) dimethyl ether (DMPEG) is also discussed. With DMPEG/hexane biphasic system, better enantioselectivities were obtained as compared to those observed in aprotic organic solvents.