Stereospecific Transformation of Protected P–H Group into P–O or P–N Group in One-Pot Reaction

A general and efficient procedure for converting 1,1-diethoxyalkylphosphinates into phosphonates or phosphonamides is described by the application of bromine with moderate to high yields and good purity in a one-pot reaction. H-Phosphinate reacts stereospecifically with bromine and subsequently couples with nucleophile to form the corresponding optically active R1P(O)(OEt)X with retention of configuration at the phosphorus center. For α-amino-H-phosphinates, the transformation could be realized without the protection of the amino group.