Catalytic Processes for Chemical Conversion of Carbon Dioxide into Cyclic Carbonates and Polycarbonates

Chemical fixation of CO2 has received much attention because CO2 is the most inexpensive and renewable carbon resource from the viewpoint of green chemistry and atom economy. The kinetic and thermodynamic stability of CO2 molecule presents significant challenges in designing efficient chemical transformations based on this potential feedstock. Currently, cyclic carbonates and polycarbonates are both valuable products, and the coupling of CO2 and epoxides is one of the most promising and eco-friendly methods for chemical conversion of CO2 into cyclic carbonates and/or polycarbonates. In this review, we will mainly discuss the synthesis of polycarbonates or cyclic carbonates catalyzed by metalsalen complexes through adjusting the architecture of the ligands and optimizing reaction conditions, such as temperature, pressure, co-catalysts, epoxide concentration. Furthermore, the recent progress for the synthesis of cyclic carbonates via the coupling reactions of epoxides and CO2 mediated by both homogeneous and heterogeneous catalysts is particularly reviewed.