Synthesis of bis(cyclic carbonate) and propylene carbonate via a one-pot coupling reaction of CO2, bisepoxide and propylene oxide

Abstract

The effective transformation of carbon dioxide (CO2) into valuable products is promising in green and sustainable chemistry. The coupling reaction of CO2 with epoxides to afford cyclic carbonates is an atom-economic pathway for CO2 fixation. Many catalysts have been developed for this coupling reaction, however, very few of them were reported for the coupling reaction of CO2 with bisepoxides. This work describes an efficient one-pot coupling reaction of CO2, propylene oxide (PO) and bisepoxides without the addition of external organic solvents by using a nanolamellar zinc-cobalt double metal cyanide complex (Zn–Co(III) DMCC) as the catalyst and cetyltrimethyl-ammonium bromide (CTAB) as the co-catalyst. Propylene carbonate (PC) and bis(cyclic carbonate)s were obtained at the same time with high monomer conversions (PO: 93.6%, bisepoxides: 82.9%). The in situ produced PC acted as a good solvent for the coupling reaction of CO2 with bisepoxides. Two products could be easily separated by distillation or precipitation. The application of the obtained bis(cyclic carbonate)s was also preliminarily investigated. A non-isocyanate route for synthesizing polyurethanes with massive hydroxyl groups was proposed.