咪唑阴离子型碱性离子液体的合成及其催化Knoevenagel缩合反应

Synthesis of a Basic Imidazolide Ionic Liquid and Its Application in Catalyzing Knoevenagel Condensation

设计合成了由1-丁基-3-甲基咪唑阳离子与咪唑阴离子搭配的[bmim]Im新型碱性离子液体并对其碱性进行研究.[bmim]Im离子液体的碱性与[bmim]OH的碱性接近且强于[bmim]OAc.在水溶液及室温条件下,2%的[bmim]Im离子液体对系列芳香醛与活泼的亚甲基化合物之间的Knoevenagel缩合反应具有较好的催化性能,目标产物的收率达到86%～95%,选择性为100%.同时,该催化剂体系具有良好的循环性能.

A novel basic ionic liquid paired by 1-butyl-3-methylimidazolium cation and imidazolide anion （[ bmim] Im） was synthesized and its basicity was investigated. The basicity of [bmim] Im approaches to that of [bmim]OH and is much stronger than that of [ bmim] OAc. In aqueous solution and under room temperature, 2 % of [ bmim ]Im showed well catalytic properties for Knoevenagel condensations between aromatic aldehyde and active methylene compounds with 86 %-95 % yield and 100% selectivity of ylidenemalononitriles. Experimental results showed that this kind of imidazolide ionic liquid has better recycle ability as well.