Chiral Brønsted acid-catalyzed hydrophosphonylation of imines-DFT study on the effect of substituents of phosphoric acid

The enantioselective hydrophosphonylation reaction of diisopropyl phosphite with aldimine furnished α-amino phosphonates with high enantioselectivities by means of a chiral phosphoric acid. DFT calculation of the effect of 3,3′-substituents of the phosphoric acid revealed the reason for the high enantioselectivities.