Oxidative carbonylation of phenol to diphenyl carbonate catalyzed by Pd complex with diimine ligands

Pd complexes with diimine ligands were investigated as novel Pd catalysts for direct synthesis of diphenyl carbonate by oxidative carbonylation of phenol using carbon monoxide and air. Best efficiency was obtained by using a PdCl2(ArN=CH–)2 or PdCl2(ArN=CMe–)2/Mn(TMHD)3/(Ph3P=)2NBr system where TOF reached 8.08 and 8.00 mol-DPC/mol-Pd h, respectively. The efficiency was increased with increases in the CO pressure.