Oxidative carbonylation of phenol to diphenyl carbonate catalyzed by bis(benzonitrile)dichloropalladium in the presence of polyvinylpyrrolidone

Abstract

Pd(PhCN) 2Cl 2 [bis(benzonitrile)dichloropalladium] were investigated in the presence of polyvinylpyrrolidone (PVP) as a polymer support for the direct synthesis of diphenyl carbonate (DPC) by the oxidative carbonylation of phenol using carbon monoxide (CO) and air. Pd(PhCN) 2Cl 2 was found to be more efficient than the conventional PdBr 2 system, and its efficiency was accelerated in the presence of high molecular weight PVP with M w=360,000 and 1,300,000. The best efficiency of Pd(PhCN) 2Cl 2/Mn(TMHD) 3 [tris(2,2,6,6-tetramethyl-3,5-heptanedionato)manganese]/(Ph 3P) 2NBr [bis(triphenylphosphoranylidene)ammonium bromide] system was obtained by using 0.241 mmol of PVP with M w=360,000 where TOF (turnover frequency) reached 11.31 (mol-DPC/mol-Pd h, Pd/Mn/Br/phenol=1/2/20/2667; CO 0.50 MPa; air 0.25 MPa, 100°C, 3 h).