多羟基双（季铵）离子液体在温和条件下高效催化剂固定CO₂

Efficient fixation of CO₂ to cyclic carbonates and oxazolidinones with multi-hydroxyl bis-(quaternary ammonium) ionic liquids as catalysts under mild conditions

摘要

制备了一系列多羟基双（季铵）离子液体（ILs1‒7）作为化学固定二氧化碳（CO₂）的双功能催化剂.这些离子液体化合物是高效的催化剂，可通过CO₂与环氧烷或氮丙啶之间在没有助催化剂、金属和溶剂的情况下，环加成反应合成环状碳酸酯和𫫇唑烷酮，具有良好的产率和高选择性.由于羟基和卤素阴离子的协同作用，环加成反应在高压和室温下都能顺利进行.5位和4位取代𫫇唑烷酮的选择性可以通过改变反应条件调节.最后，根据文献和实验结果，提出了CO₂与环氧烷和氮丙啶的活化机理.

Abstract

A series of multi-hydroxyl bis-（quaternary ammonium） ionic liquids （Ils1‒7） was prepared as bifunctional catalysts for the chemical fixation of CO₂. All these ionic liquid compounds were efficient for the catalytic synthesis of cyclic carbonates and oxazolidinones via the cycloaddition reactions between CO₂ and epoxides or aziridines with excellent yield and high selectivity in the absence of co-catalyst， metal and solvent. Due to the synergistic effects of hydroxyl groups and halogen anion， the cycloaddition reactions proceeded smoothly either at atmospheric pressure or room temperature. The selectivity for substituted oxazolidinones at 5- and 4- positions can be tuned via changing the reaction conditions. Finally， possible mechanisms including the activation of both CO₂ and epoxide or aziridines were proposed based on the literatures and experimental results.

关键词

二氧化碳的化学转化 / 多羟基双季铵 / 离子液体

Key words

chemical conversion of CO₂ / multi-hydroxyl bis-（quaternary ammonium） / ionic liquids

基金资助

国家自然科学基金资助项目(51073175)

中央高校基本科研业务费专项资金资助项目(CZT19002)