Effect of inorganic redox cocatalyst on Pd-catalyzed oxidative carbonylation of phenol for direct synthesis of diphenyl carbonate

A catalyst system for direct synthesis of diphenyl carbonate by oxidative carbonylation of phenol was investigated with special emphasis on the inorganic redox cocatalyst component. Besides the inorganic redox cocatalyst, the catalyst system was composed of a Pd carbonylation catalyst, an organic redox cocatalyst, a base and a drying agent. Ce(OAc)(3). H2O was found to be the most efficient inorganic redox cocatatyst giving DPC in 76% yield with a Pd turnover number of 250 and without producing any major side products.