Synthesis of P-chiral enephosphonic acid derivatives

An efficient and convenient synthesis of chiral enephosphonic acid derivatives (enephosphonates, enephosphonamides, enephosphinates) was reported by a two-step procedure involving alkylidenediphosphorylation of nucleophiles followed by a Horner–Emmons olefination. Depending on the selected strategy, the synthesis could be executed according to a one-pot or a two-step reaction sequence. Regioselectivity of Horner–Emmons reaction and 31P-NMR study of diphosphorylated anions were described.