Green Synthesis of 2-Oxazolidinones by an Efficient and Recyclable CuBr/Ionic Liquid System via CO<sub>2</sub>, Propargylic Alcohols and 2-Aminoethanols
Chao Bu, Yanyan Gong, Minchen Du, Cheng Chen, Somboon Chaemchuen, Jia Hu, Yongxing Zhang, Heriberto Díaz Velázquez, Ye Yuan, Francis Verpoort
Abstract
With the aim of profitable conversion of carbon dioxide (CO<sub>2</sub>) in an efficient, economical, and sustainable manner, we developed a CuBr/ionic liquid (1-butyl-3-methylimidazolium acetate) catalytic system that could efficiently catalyze the three-component reactions of propargylic alcohols, 2-aminoethanols, and CO<sub>2</sub> to produce 2-oxazolidinones and α-hydroxy ketones. Remarkably, this catalytic system employed lower metal loading (0.0125–0.5 mol%) but exhibited the highest turnover number (2960) ever reported, demonstrating its excellent activity and sustainability. Moreover, our catalytic system could efficiently work under 1 atm of CO<sub>2</sub> pressure and recycle among the metal-catalyzed systems.