Imidazolium based ionic liquids bearing a hydroxyl group as highly efficient catalysts for the addition of CO2 to epoxides

A variety of beta-hydroxyl-functionalized imidazolium salts were synthesized and characterized. Their catalytic activities were investigated in the synthesis of cyclic carbonates from CO2 and epoxides. In comparison to ionic liquids previously reported, it was found that 12 was a very active catalyst at mild reaction conditions (60 degrees C, 0.5 MPa, 8 h). Moreover, catalyst 12 could be reused five consecutive times without much loss of activity.