Carbon Acidity. 63. Equilibrium Ion Pair Acidities of Some Phosphorus-Substituted Carbon Acids

Article abstract of DOI:10.1021/jo00344a004

Ion-pair C-H acidities are reported as pK_CsCHA for bis(diphenylphosphino)methane (1, 31.1), (p-phenylbenzyl)diphenylphosphine (3, 31.0), p-tolyldiphenylphosphine (4, 37.9), and several of the corresponding phosphine oxides.The diphenylphosphine group is about as anion stabilizing as p-biphenyl.The Ph2P(O) group is additionally stabilizing because of enhanced ion-pair interaction.The pK_CsCHA of benzyldiphenylphosphine (2) can be estimated to be about 32.