A protic ionic liquid catalyzes CO₂ conversion at atmospheric pressure and room temperature: synthesis of quinazoline-2,4(1H,3H)-diones.
The chemical fixation of CO2 under mild reaction conditions is of significance from a sustainable chemistry viewpoint. Herein a CO2-reactive protic ionic liquid (PIL), [HDBU(+)][TFE(-)], was designed by neutralization of the superbase 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) with a weak proton donor trifluoroethanol (TFE). As a bifunctional catalyst for simultaneously activating CO2 and the substrate, this PIL displayed excellent performance in catalyzing the reactions of CO2 with 2-aminobenzonitriles at atmospheric pressure and room temperature, thus producing a series of quinazoline-2,4(1H,3H)-diones in excellent yields.
Institute of Chemistry, Chinese Academy of Sciences, No. 2, Zhongguancun Beiyijie, Beijing 100190 (China).
Yanfei
Y
Zhao
Bo
B
Yu
Zhenzhen
Z
Yang
Hongye
H
Zhang
Leiduan
L
Hao
Xiang
X
Gao
Zhimin
Z
Liu
carbon dioxide fixation; heterocylces; ionic liquids; reaction mechanism; synthetic methods