Synthesis of Diaryl Diazaphosphonates via 1,6-Hydrophosphonylation of p-Quinone Methides with N-Heterocyclic Phosphine-Thioureas.

A mild, efficient method for the synthesis of diaryl diazaphosphonates via 1,6-hydrophosphonylation/aromatization of p-quinone methides (p-QMs) with N-heterocyclic phosphine-thioureas has been developed. This transformation proceeds without any additive or catalyst under mild reaction conditions and tolerates a wide range of p-QMs. This methodology provides a straightforward access to diaryl phosphonate derivatives in good to excellent yields (up to 99%).