Asymmetric organocatalysis is now recognized as the third pillar of asymmetric synthesis. Recent years have witnessed increasing interest towards the use of highly active and stereoselective organocatalysts. This critical review documents the advances in the development of chiral organocatalysts which are systematically used in ≤3 mol% loading in all the sub-areas of the field, namely aminocatalysis, Brønsted acids and bases, Lewis acids and bases, hydrogen bond-mediated catalysis, phase transfer and N-heterocyclic carbene catalyses (194 references).

Multilayered, covalently supported ionic liquid phase (mlc-SILP) materials were synthesized by using a new approach based on the grafting of bis-vinylimidazolium salts on different types of silica or polymeric supports. The obtained materials were characterized and tested as catalysts in the reaction of supercritical carbon dioxide with various epoxides to produce cyclic carbonates. The material prepared by supporting a bromide bis-imidazolium salt on the ordered mesoporous silica SBA-15 was identified as the most active catalyst for the synthesis of cyclic carbonates and displayed improved productivity compared with known supported ionic liquid catalysts. The catalyst retained its high activity upon reuse in consecutive catalytic runs. This is the first report of the application of mlc-SILP materials as catalysts in a reaction for the fixation of carbon dioxide. Rapid, parallel screening and comparison of the catalysts was performed by means of high-throughput experimentation.

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