Catalysis in Ionic Liquids: a Key to Sustainable Chemistry

A key to the development of innovative sustainable technology platforms is represented by the combination of different green strategies. The access to new synthetic processes deriving from the merging of heterogeneous catalysis with intrinsically safer solvents such as ionic liquids, and possibly using flow through techniques, is discussed in this chapter. Examples taken from the very recent literature are analysed and classified according to four different strategic approaches to generate catalysis in ionic liquid media; (i) the ionic liquid is the solvent for the catalytic reaction, (ii) the ionic liquid is both the solvent and the catalyst (or pre-catalyst), (iii) the ionic liquid is simply used as the catalyst, easily removable from the reaction mixture, (iv) the ionic liquid is supported in the form of a thin layer on a solid support. In the last case, the solid material is exploitable in fixed bed reactors, thus rendering possible the application of continuous flow technologies.