A review of ionic liquids: Applications towards catalytic organic transformations

Ionic liquids (ILs) have emerged as an environmentally friendly alternative to the volatile organic solvents. ILs which are made up of cationic and anionic components can be designed to possess a definite set of properties. In this context, the term “designer solvents” has been used to demonstrate the potential of these environment-friendly ILs in chemical reactions. Being designer solvents, they can be modulated to suit the reaction conditions, therefore earning the name “task specific ILs.” Since these liquids are able to dissolve several transition metal complexes, they have often been employed in recent times in several catalytic organic reactions to enhance reaction rates and selectivity. Though primarily used as solvents, they are now finding applications in various fields like catalysis, electrochemistry, spectroscopy, and material science to mention a few. ILs is capable to restrict many of the negative effects of the conventional organic solvents or other catalysts during catalytic reactions and have successfully been used in various catalytic areas affording high catalytic activity. The present review is aimed at exploring the structural characteristics, properties, preparation and applications of ILs in catalytic organic transformations.