Fixation of CO2 in structurally diverse quinazoline-2,4(1H,3H)-diones under ambient conditions

The chemical fixation of CO2 is intriguing to eliminate its impact on climate, but harsh reaction conditions are often involved. Herein, we report a new ionic liquid cholinium 2,4-dichlorophenolate which can efficiently promote the conversion of CO2 to quinazoline-2,4(1H,3H)-diones at 1atm CO2 and near room temperature without any other additives. This mild reaction system is friendly to biomolecules such as glycoside and nucleoside with sensitive functional groups, leading to the successful CO2 fixation in biomolecules modification. In addition, this reaction system is easy to conduct, and the target compounds can be separated by simple precipitation after the reaction. The reaction mechanism studies reveal that the ionic liquid have triple activation effects toward all of the three reaction centers of the target reaction. The triple activation in one ionic liquid gives important clues for the designation of ionic liquids according to a specific reaction.