Organocatalytic Direct Enantioselective Hydrophosphonylation of N-Unsubstituted Ketimines for the Synthesis of α-Aminophosphonates

We report an organocatalyzed direct enantioselective hydrophosphonylation of N-unsubstituted ketimines that affords N-unprotected α-tetrasubstituted α-aminophosphonates without protection/deprotection steps. The reaction is suitable for N-unsubstituted isatin-derived and trifluoromethyl ketimines, affording products in high yields with excellent enantioselectivity. Applications of the reaction and a proposed transition state model are also described.