New Aspects Connected with the Synthesis of H-Phosphinate Anhydrides

A novel reaction between sodium salt ofphenylphosphinic acid PhP(O)(OH)H (1) and various phosphorus electrophiles, R 2 P(O)Cl (2; R = alkyl, aryl, alkoxy or aryloxy) has been described. The presented reaction showed a high selectivity (yield up to 96%) in the products of the symmetric phosphorus anhydrides, R 2 P(O)-O-(O)PR 2 (4), which preferentially come from the starting phosphorus electrophiles (2). The results demonstrate that the phosphorus-phosphorus mixed anhydrides, RPH(O)-O-(O)PR 2 (3) are unstable under basic condition and possibly decomposed with expulsion of a phosphinylidene (Ph-P=O) fragment (6).