Ionic liquids in catalysis: A review

Abstract

Abstract The organic salts that show melting points less than 100 °C (i.e. under the boiling temperature of water) are referred to as Ionic liquids/fluids (ILs), they describe a fascinating class of liquid materials distinguished by exceptionally low vapor pressure. Ionic liquids (ILs) have originated from volatile organic solvents as an environmentally friendly alternative. ILs comprising of components, both cationic and anionic, having certain properties that can be produced. The ability of such environmentally friendly ILs in chemical reactions is described by referring to them as “designer solvents”. They are moldable to match the conditions of the reaction and thus become “task-specific ILs.” Their ability to dissolve transition metal complexes makes them useful in increasing, reaction rates and selectivity in many catalytic organic reactions. Some of the characteristic physical properties of room temperature organic ionic liquids (RTILs) are low hydrophobicity, low volatility, and low lipophilicity, which makes their nature independent among other liquids. This nature supports homogeneous as well as heterogeneous catalysts thus, making reactions economically and environmentally friendly. This review discusses the applications of ILs in organic catalytic transformation.