Arbuzov-type reaction of acylphosphonites and N-alkoxycarbonylimine cations generated in situ with trifluoroacetic anhydride

A mild procedure for the synthesis of N-protected α-aminoalkylphosphinic acids by the reaction of N,N′-benzylidene- or N,N′-alkylidenebiscarbamates, trifluoroacetic anhydride and the corresponding alkylphosphonous acids in methylene chloride or toluene is described. The results obtained confirm the earlier proposed mechanism for amidoalkylation of hydrophosphorylic compounds involving an Arbuzov-type reaction step.