Synthesis of Chiraphos via asymmetric hydrogenation of 2,3-bis(diphenylphosphinoyl)buta-1,3-diene
Abstract
(S,S)-2,3-Bis(diphenylphosphinoyl)butane, an immediate precursor of (S,S)-CHIRAPHOS, can be obtained with 70% de and 71% op via double asymmetric hydrogenation of 2,3-bis(diphenylphosphinoyl)buta-1,3-diene in the presence of Ru(S)-BINAP catalysts.