JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL, v.115, no.2, pp.241 - 246
Abstract
The oxidative coupling of methyl benzoate in the presence of a catalyst system comprising of Pd(OAc)(2) and a vanadium-containing heteropolyacid produced 2,2'-biphenic acid dimethyl ester with a high selectivity. The mode of coordination of methyl benzoate to palladium and the non-coordinating nature of the heteropolyacid appeared to be responsible for the unusual selectivity. Addition of Hg(OAc)(2) or triphenyl phosphine increased greatly the conversion of methyl benzoate without impairing the selectivity to the 2,2'-isomer. The catalyst deactivated with reaction time, mainly due to water produced from the reaction