Continuous-Flow Synthesis of Cyclic Carbonate With Supercritical CO2 Using Polystyrene-Supported Imidazolium Catalysts.

Supercritical carbon dioxide (scCO2) is well-known for its low viscosity and high diffusivity, which are widely utilized in CO2 transportation and storage processes within the carbon capture, utilization, and storage (CCUS) strategy. Additionally, its strong solvation capacity, environmental benignity, and facile separation make it an attractive solvent for organic synthesis. In this study, we successfully apply scCO2 in CO2 cycloaddition with epoxides for continuous cyclic carbonate synthesis using our developed imidazolium-based polymer-supported ionic liquid (Im-PSIL) catalysts. The application of this scCO2-assisted catalytic system to five different epoxide substrates, including essential industrial chemicals such as epichlorohydrin and glycidol, delivered moderate to excellent yields, highlighting its high value for the chemical industry.