Cycloaddition Reactions of Epoxides and CO2 by the Novel Imidazolium-Functionalized Metalloporphyrins: Optimization and Analysis using Response Surface Methodology

The production of cyclic carbonates using CO(2)and epoxides has received great attention due to 100 % atom utilization. Herein, novel imidazolium-containing metalloporphyrins were synthesized as bifunctional catalysts for the cycloaddition reactions of epoxides and CO2. The reaction conditions were optimized and analyzed with the response surface methodology. Under the optimum condition using Zn-porphyrin1as the catalyst, the turnover number (TON) and turnover number frequency (TOF) for the cycloaddition of CO(2)and ECH were 11,629 and 1,735, respectively. In addition, analysis of the RSM indicated that the CO(2)pressure had only a small impact on the yield. Based on this conclusion, the catalytic activity of1was further evaluated under mild conditions. Regardless of whether the CO(2)pressure is high or ambient, this Zn-porphyrin exhibited an excellent performance with a high turnover number frequency.