Rh-catalyzed asymmetric hydrogenation by using a new family of C2-symmetric bisphosphinites and a bisaminophosphine as ligands

The application of a new family of four-chiral-centered C2-symmetric bisphosphinites (1, 2 and 3) and the bisaminophosphine 4 in Rh-catalyzed asymmetric hydrogenation of dehydroamino acids has been examined. Up to 98% ee was obtained in the hydrogenation of α-acetamidocinnamic acid, which is comparable with the enantioselection obtained from the best chiral bisphosphinites and bisaminophosphines.