Synthesis of chiral ortho-thio-substituted phenyl phosphonodiamidates via a P–S to P–C rearrangement

The ortho-lithiation of a phenyl phosphorodiamidothioate derived from an enantiopure C2-symmetric diamine is studied. It is shown that the migration of the diaminophosphoryl group from sulfur to carbon, leading to an ortho-sulfanylated phenyl phosphonodiamidate, only occurs in the presence of an alkylating agent or a Lewis acid as BF3·Et2O. The influence of the chiral diaminophosphoryl group on the stereoselectivity of the oxidation of the ortho-sulfanyl or alkylsulfanyl group is also examined.