Bifunctional One‐Component Catalysts for the Addition of Carbon Dioxide to Epoxides

Abstract

Abstract Several bifunctional ammonium salts were synthesized and employed as one‐component catalysts for the conversion of CO 2 and epoxides to produce cyclic carbonates. These catalysts show superior activities compared to their monofunctional analogs. A turnover number of up to 693 and a turnover frequency of up 392 h −1 could be achieved for the best catalyst. Moreover, the effect of various solvents has been studied. All employed solvents and the product formed had a negative influence on substrate conversion. The scope and limitation of the reaction has been studied carefully for two general reaction protocols at 45 and 90 °C. In over 20 examples, the isolated yields after filtration were 90 %. In addition, we present the first organocatalyzed synthesis of a cyclohexene‐based naturally occurring cyclic carbonate, and its molecular structure was determined by XRD. Furthermore, we demonstrate that the reaction can be performed even on a multigram scale and can be monitored by in situ FTIR spectroscopy.