Synthesis of Pd(C 4H 2O 4)(C 4H 8N 2) 0.5 Complex and the Catalytic Activity for Oxidative Carbonylation of Phenol

Abstract

A novel complex Pd(C 4H 2O 4)(C 4H 8N 2) 0.5 has been synthesized by solvent thermal synthesis and used as a heterogeneous catalyst for direct synthesis of diphenyl carbonate (DPC) by oxidative carbonylation of phenol. In the reaction system of Pd(C 4H 2O 4)(C 4H 8N 2) 0.5/Cu(OAc) 2/tetrabutylammonium bromide/hydroquinone/4A molecular sieves, the effect of reaction temperature, time and CO pressure on catalytic activity were investigated, and the results revealed that the catalyst could catalyze oxidative carbonylation of phenol effectively. Under suitable reaction conditions of T=90°C, t=4 h, p(O 2)=0.3 MPa, p(CO)=3.9 MPa and CH 2Cl 2 as solvent, the turnover number (TON) of diphenyl carbonate can reach about 13.50 (mol-DPC/mol-Pd), which is higher than the TON for pure PdCl 2 under the same reaction conditions.