N-Heterocyclic Carbene-Pyridine Manganese Complex/Tetrabutylammonium Iodide Catalyzed Synthesis of Cyclic Carbonate from CO2 and Epoxide

The bidentate N-heterocyclic carbene (NHC)-pyridine nitrogen manganese complex catalyzed coupling reaction of epoxides with CO2 was developed. The binary system resulting from the manganese complex Mn-2 in combination with tetrabutylammonium iodide (TBAI) exhibits the high activity for the synthesis of cyclic carbonate from epoxides and CO2. The binary catalytic system is suitable for a broad range of substrates scope, such as terminal epoxides and sterically hindered internal epoxides. A possible catalytic pathway was elaborated by UV-vis, FT-IR and HRMS method.