Titanium Incorporated Mesoporous Silica Immobilized Functional Ionic Liquid as an Efficient Reusable Catalyst for Cycloaddition of Carbon Dioxide to Epoxides

Abstract

A series of functionalized ionic liquids immobilized onto SBA‐15 mesoporous materials were prepared, characterized and evaluated as catalysts in cycloaddition of CO2 to epoxides. Most of these immobilized ILs perform well in the reaction, especially the multifunctional titanium incorporated SBA‐15 immobilized heterogeneous catalysts Ti‐SBA‐15@ILClCH2COO(0.5) and Al‐SBA‐15@ILClCH2COO(0.5). The catalytic tests revealed that Ti‐SBA‐15@ILClCH2COO(0.5) was the best and powerful catalyst in the cycloaddition for the preparation of cyclic carbonates with high to excellent yields. The heterogeneous catalyst can be easily separated from the reaction mixture by filtration and reused in six consecutive cycles without significant loss in catalytic activity. The studies demonstrate that the well designed supported catalysts via cooperative catalysis of the supported carrier, anion sites of ILs is a promising platform for construction of novel and highly efficient catalytic transformation systems.

Recyclable and Magnetically Functionalized Metal–Organic Framework Catalyst: IL/Fe3O4@HKUST-1 for the Cycloaddition Reaction of CO2 with Epoxides

“…Based on the experimental observations that the presence of both HKUST-1 and IL is required for effective catalysis, ,− a plausible cycloaddition reaction mechanism catalyzed by the IL/Fe 3 O 4 @HKUST-1 involving the consecutive insertion of carbon dioxide, ring-opening of epoxide, and ring closure of cyclic carbonate is presented in Scheme . Initially, the positively charged ammonium ion acts as a Lewis acid to polarize and activate the C–O bond in CO 2 , followed by the nucleophilic addition of the BF 4 – group to the carbon atom of carbon dioxide.…”

Homogeneous and Heterogeneous Ionic Liquid System: Promising “Ideal Catalysts” for the Fixation of CO2 into Cyclic Carbonates

“…SBA-15 supported ILs were widely prepared and studied as catalysts for the fixation of CO 2 . [109][110] The mesoporous properties and the hydroxyls on its pore surface make SBA-15 a suitable supports of SILCs. Abundant hydroxyls provide possibility of grafting ILs onto the internal pore surface of SBA-15 via chemical bonds.…”

Functionalized Silicas for Metal‐Free and Metal‐Based Catalytic Applications: A Review in Perspective of Green Chemistry

“…Immobilized ILs are likely to be used in continuous‐flow‐operated fixed‐bed processing . With the ease of synthesis using imidazole or sodium imidazolide, imidazolium ILs have received greater attention amidst the other silica supported ILs . D. Elhamifar et al.…”