PHOTOLYSIS OF 7-(2,4,6-TRIALKYLPHENYL-)7-PHOSPHANORBORNENE 7-OXIDES IN THE PRESENCE OF PROTIC SPECIES

Irradiation of 7-(2,4,6-trialkylphenyl-)7-phosphanorbornene 7-oxides a t 254 nm in the presence of alcohols or water led to H-phosphinic acid derivatives. The experimental data are consistent with the mechanism established earlier for P-phenyl derivatives, involving a five-coordin ate adduct from the interaction of the phosphanorbornene and the proti c species which then fragments. There is no evidence that the larger s ubstituent allowed a competing reaction to occur where the first step is unimolecular fragmentation to a two-coordinate phosphoryl species. (C) 1997 John Wiley & Sons, Inc.