Synthesis of 2, 2, 4-trimethyl-1, 3-pentaerediol monoisobutyrate catalyzed by homogeneous catalysis-liquid/liquid separation catalytic system based on Bibasic sites Ionic Liquids

Herein a novel homogeneous catalysis-liquid/liquid separation catalytic system based on 1, 8-diazabicyclo-[5.4.0] undec-7-ene (DBU)-functionalized, 1, 1, 3, 3-tetramethyl guanidine-functionalized and imidazolium-functionalized bibasic sites ionic liquids (BSILs) ([HDBU]IM, [Aemim]IM, [TMG]IM, [Aemim]Pro, [Aemim]Gly, [HDBU]Pro and [HDBU]Gly) with a room temperature liquid/liquid phase transition characteristic were reported. And for the first time, this novel catalytic system was employed for the synthesis of 2, 2, 4-trimethyl-1, 3-pentaerediol monoisobutyrate (CS-12), achieving homogeneous catalysis, easy recycling and long service-life of the catalyst. Additionally, the mechanism of homogeneous catalysis-biphasic separation might be explained by the solubility of reactant and product in BSILs/H2O catalytic system and the existence H-bonding between BSILs and H2O. Bibasic sites were confirmed by two endothermic peaks on the TG-DCS curve of [Aemim]IMC (the CO(2)captured by [Aemim]IM).