Asymmetric catalysis in ionic liquids: Easy recycling of catalyst and improvement of catalytic performances

Abstract

tAmbient temperature ionic liquids have recently come to be regarded as an eco-friendly alternative to volatile organic solvents in chemical processes, due to their negligible vapor pressure and high thermal stability. In these solvents, chiral catalysts having polar or ionic character can be immobilized without additional structural modification and thus the ionic solutions containing the catalyst can easily be separated from the reagents and reaction products, and then, be reused. More interestingly, switching from an organic solvent to an ionic liquid often results in an improvement in catalytic performance (e.g., rate acceleration, enantioselectivity improvement and an increase in catalyst stability).