Redox Cocatalyst Research Articles

Direct synthesis of diphenyl carbonate by oxidative carbonylation of phenol using Pd–Cu based redox catalyst system

A catalyst system was designed for direct synthesis of diphenyl carbonate by oxidative carbonylation of phenol. Besides Pd carbonylation catalyst, inorganic and organic redox cocatalysts were included in the catalyst system for in situ regeneration of active Pd species. Copper(II) acetate was used as inorganic redox cocatalyst and hydroquinone was found to give good results as organic redox cocatalyst. Efficiency of various bases, effect of a drying agent, and optimum reaction conditions for achieving high catalytic activity were also investigated in detail. Using suitable components of catalyst system and under optimum reaction conditions, a Pd turnover number of 250 could be obtained.

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 cocatalyst giving DPC in 76% yield with a Pd turnover number of 250 and without producing any major side products.