Organocatalytic Phosphonylation of in Situ Formed o-Quinone Methides.

A new class of Brønsted acid catalysts based on N-heterocyclic phosphorodiamidic acids (NHPAs) has been developed. The NHPA catalyst promotes phospha-Michael addition reaction of trialkylphosphites to in situ generated ortho-quinone methides (o-QMs) for the construction of diaryl phosphonates in moderate to excellent yields with 1.5 mol % catalyst. Diastereoselective synthesis of P-chiral phosphinate esters is achieved with the use of dialkyl phenylphosphonites.