Catalytic Asymmetric Hydrophosphonylation of Ketimines

Catalytic asymmetric hydrophosphonylation of aromatic and aliphatic N-thiophosphinoyl ketimines with dialkyl phosphite was efficiently promoted by as little as 0.5 mol% of catalyst loading at ambient temperature. The catalyst can be recovered for repeated use, and facile removal of the thiophosphinoyl group allowed for ready access to the phosphonic acid analogue of enantioenriched α,α-disubstituted α-amino acids.