Chiral α-Amino Phosphonates via Rhodium-Catalyzed Asymmetric 1,4-Addition Reactions

A new approach for the preparation of enantioenriched alpha-amino phosphonates and derivatives is described. Indeed, the rhodium-catalyzed asymmetric 1,4-addition of potassium organotrifluoroborates to dehydroaminophosphonates afforded alpha-amino phosphonates in good yields and high enantioselectivities (up to 96%) using Difluorphos as a chiral ligand.