Efficient Synthesis of Diphenyl Carbonate from CO₂, Phenol, and Carbon Tetrachloride under Mild Conditions

Abstract

Diphenyl carbonate (DPC) has outstanding practical potential, especially as a key building block for the phosgene-free synthesis of polycarbonate (PC) in the chemical industry. The synthesis of DPC from CO 2 has been investigated for decades, but exploring highly efficient catalytic systems is still challenging. Herein, an efficient catalytic system for the direct synthesis of DPC from CO 2 , phenol, and carbon tetrachloride was developed by using a ZnCl 2 / copper triflate (Cu(OTf) 2 ) composite catalyst. For the first time, high yield and high selectivity were achieved for DPC synthesis under mild conditions, even at atmospheric pressure. Carefully designed control experiments and DFT studies indicated that the synergistic activation of Cu(OTf) 2 and its anion complex with ZnCl 2 for phenol and CO 2 led to a remarkably improved catalytic activity through a Lewis acid-assisted catalysis. This study not only provides a new strategy for efficient preparation of DPC but also offers an effective pathway for better CO 2 utilization.

Facile One-Pot Preparation of Organotin-Oxometalate Polymers for Efficient Synthesis of Dimethyl Carbonate from CO2

“…When the catalyst amount was further increased to 0.3 g, the DMC yield declined. The reason was plausibly the difficult mass transfer of the catalyst due to the particle aggregation which resulted from the use of excessive catalyst. , Finally, the reaction time influence on the DMC yield was studied (Figure S5D). It was noted that DMC yield increased with reaction time prolongation and reached a maximum value of 15.7 mmol g cat –1 at 3 h. However, further prolonging the reaction time did not increase the DMC yield.…”

Reaction Pathways in Carbonates and Esters

“…Nerveless an efficient catalytic system for the direct synthesis of DPC from CO 2 , phenol, and carbon tetrachloride was developed using a ZnCl 2 /copper triflate (Cu(OTf) 2 ) composite catalyst (Scheme 9). [95] Such reaction is central for the preparation of polyurethanes by a phosgene-free process. Polyurethanes are currently obtained by the reaction of polyols with isocyanates, which are obtained by the reaction of the primary amines with phosgene.…”

“…Nerveless an efficient catalytic system for the direct synthesis of DPC from CO 2 , phenol, and carbon tetrachloride was developed using a ZnCl 2 /copper triflate (Cu(OTf) 2 ) composite catalyst (Scheme 9). [95] …”