Preparation Of Functionalized Liquids And Their Applications For The Synthesis Of Cyclic Carbonates

Carbon dioxide is a major greenhouse and it has already become a serious problem in constructing sustainable society as its concentration continues to increase.But it is also a very important C1 resource.Using carbon dioxide as a chemical raw material can not only solve the environmental problems that caused by carbon dioxide,but also develop high value-added products.The reaction of carbon dioxide and epoxide to synthesize cyclic carbonates is one of the most promising methods for effective fixation of carbon dioxide,because of high atom utilization and fewer by-products.In this paper,the new functionalized ionic liquid was developed to catalyze the synthesis of cyclic carbonates from carbon dioxide.The five functional imidazolium ionic liquids?[HEMim][Glu],[HEMim][Asp],[HEBim][Asp],[HEBim][Ala],[HEBim][His]?were successfully synthesized and characterized by ¹H NMR,¹³C NMR and FT-IR spectroscopy.Higher yields can be obtained by applying them as catalysts to cycloaddition reaction of carbon dioxide and epoxides.Under optimized conditions?the amount of catalyst is 0.8 mol%,90?,0.25 Mpaand 12 h?,the yield of the cyclic carbonate can be more than 90%.The five functional quaternary ammonium salt ionic liquids([HETEA][But],[HETEA][Suc],[HETEA][Ace],[HETEA][Gly],[N₁₂₂₂][Gly])were successfully synthesized and characterized by ¹H NMR,¹³C NMR and FT-IR spectroscopy.Higher yields can be obtained by applying them as catalysts to reaction of carbon dioxide and epoxides.Under optimized conditions?the amount of catalyst is 1 mol%,110?,1Mpaand 12 h?,the yield of the cyclic carbonate can be more than 85%.Catalytic system developed in this paper exhibitedhigh catalytic activity for the reaction of carbon dioxide and epoxides under mild conditions.Excellentyields of carbonate were obtained without solvent or cocatalyst.The catalyst could be reused many cycles and is an environmentally friendly catalytic system.