PALLADIUM-LEAD CATALYZED OXIDATIVE CARBONYLATION OF PHENOL

Oxidative carbonylation of phenol to form diphenyl carbonate (DPC) was examined. A novel catalyst of type Pd-Pb-NMe4Br was found to show hig h activity and selectivity for the present reaction. The Pd species se ems to work as an homogeneous catalyst. The rate of DPC formation was in first order with respect to P-O2 and [Pb], indicating that the oxyg en activation with lead compound is the rate-determining step. Concomi tant bromophenol formation was suppressed by Cu or Co additives and lo nger catalyst life was achieved with these additives. (C) 1998 Elsevie r Science B.V.