1 Green Chemistry Centre, Department College of Chemistry and Chemical Engineering, Yantai University, 32 Qingquan Road, Yantai 264005, Shandong, China. hylv@ytu.edu.cn.
Choline chloride-based deep eutectic solvents (DESs) exhibited remarkable activity in the cycloaddition of CO2 with propylene oxide (PO) in the absence of any additives under solvent- and metal-free conditions as well as recyclability.