Choline-based ionic liquids for CO₂ capture and conversion

Choline-based ionic liquids (Ch-ILs) with anions possessing interacting sites to attract CO₂ were designed, which could capture CO₂ with capacity >1.0 mol CO₂ per molar IL under ambient conditions. Moreover, this kind of ILs combining with CuCl could catalyze the formylation of amines with CO₂/H₂ at 120 °C. Especially, choline imidazolate showed the best performance, affording a series of N-formamides in excellent yields. It was demonstrated that the IL activated CO₂ and the synergistic effect between the IL and CuCl resulted in the high activity for catalysing the formylation of amines with CO₂/H₂.