Organophosphorus Chemistry without PCl 3 : A Bridge from Hypophosphorous Acid to H‐Phosphonate Diesters

A process for the conversion of hypophosphorous acid (H 3 PO 2 , HPA) and alcohols into various H‐phosphonate diesters [(RO) 2 P(O)H] is described. The new reaction provides a missing bridge between HPA and important H‐phosphonates, completely avoiding the use of PCl 3 . Nickel chloride or nickel on silica catalyze the oxidative phosphorylation of alkyl phosphinates with various alcohols or water. The reaction is atom economic and avoids the formation of waste products. The previous need for both chlorine and base is completely avoided.