Green Solvents for Sustainable Organic Synthesis

One of the key areas of Green Chemistry is the elimination of solvents in chemical processes or the replacement of hazardous solvents with environmentally benign solvents. Generally, chloroform, dichloromethane, benzene, carbon tetra chloride etc are used as a solvent in organic synthesis which is not only costly but is very harmful for those who are handling them also. Thus, the development of solvent-free alternative processes is, of course, the best solution. In cases where the solvent is needed, less hazardous replacements should be employed. The application of alternative solvents such as water, fluorous and ionic liquids, supercritical media like supercritical CO2 and their various combinations is rapidly increasing. Purification steps also generate large sums of solvent and other waste (chromatography supports, e. g. ). This Review aims to describe an overview of chemical processes employing such green solvents which are proposed as sustainable alternatives.