Supported Ionic Liquids and their Applications in Organic Transformations

Ionic liquids are one of the greener solvents which have emerged as a replacement for toxic and harmful volatile organic solvents. In the past decade, the concept of supported ionic liquids (SILs) has attracted the attention of the scientific community due to their unique chemical and physical properties. SILs can be synthesized by coating a thin layer of IL film onto/into the surface of solid support. They can be classified as supported IL phase catalyst, solid catalyst with IL and supported IL catalysis. SILs demonstrated the combined properties of both heterogeneous and homogeneous catalysts. These ILs offer several advantages such as enhanced stability, reusability, recoverability, easy product isolation, absence of IL leaching, as compared to conventional solvents. In this review, various aspects of SILs, classification, method of preparation and their applications in various organic transformations such as cross-coupling reactions, oxidation, reduction, synthesis of different heterocyclic compounds, biocatalytic reactions etc., have been discussed.