Autoxidation of Ethyl Phosphinite, Phosphonite, and Phosphite Esters

Article abstract of DOI:10.1021/jo01299a011

The AIBN-initiated autoxidations in benzene of triethyl phosphite P(OEt)3, diethyl ethylphosphonite, EtP(OEt)2, and ethyl diethylphosphinite, Et2POEt, were studied at 50 deg C.The quantitative conversion of P(OEt)3 to triethyl phosphate obeys the rate law rate = (2.0 x 1E-4 atm^-1s^-1)P_O2 and is zero order in phosphite.Autoxidation of EtP(OEt)2 and Et2POEt gives the complete mixture of intermediates and products predicted by Buckler's mechanism for the autoxidation of trialkylphosphines.At 1 atm of oxygen pressure and 0.02 M AIBN the pseudo-first-order rate law is rate = k', with k'= 7.49 x 1E-4 s^-1 for EtP(OEt)2 and 2.37 x 1E-4 s^-1 for Et2POEt.