Aminophosphine Phosphinites Derived from Chiral 1,2-Diphenyl-2-aminoethanols: Synthesis and Application in Rhodium-Catalyzed Asymmetric Hydrogenation of Dehydroamino Acid Derivatives

A series of chiral aminophosphine phosphinites DPAMPPs was synthesized from optically active 1,2-diphenyl-2-aminoethanols. The erythro-DPAMPPs were found to serve as excellent ligands for rhodium-catalyzed asymmetric hydrogenation of dehydroamino acid derivatives. For an array of dehydroamino acid precursors, remarkably high enantioselectivity (up to 98.4% e.e.) and reactivity (the ratio of substrate/catalyst up to 10000) were observed. Some factors controlling the enantioselectivity were examined and discussed.