Synthesis and high-throughput testing of multilayered supported ionic liquid catalysts for the conversion of CO2 and epoxides into cyclic carbonates

Multilayered covalently supported ionic liquid phase (mlc-SILP) materials were synthesised by graftingdifferent bis-vinylimidazolium salts on thiol-functionalised silica. These materials, which contain a crosslinkedoligomeric network of imidazolium units, were characterised and tested as catalysts for the reactionof carbon dioxide with various epoxides to produce cyclic carbonates. The materials prepared bysupporting a bis-imidazolium iodide salt with xylene or octane as a linker between the imidazoliumunits were identified as the most active catalysts and displayed high turnover numbers and improvedproductivity compared to known supported ionic liquid catalysts. The most promising mlc-SILP catalystswere further studied to tune the reaction conditions towards optimum catalytic performance and toinvestigate their versatility with different substrates and their reusability. The rapid and parallel screeningof the catalysts was efficiently carried out by means of high-throughput (HT) experimentation.