Electrolysis of Ionic Liquids. A Possible Keystone for the Achievement of Green Solvent-Catalyst Systems

The set up of sustainable procedures of synthesis requires, inter alia, a careful reconsideration of the role of the solvent and of the catalyst. In the last years, room temperature ionic liquids (RTILs) and N-heterocyclic carbenes (NHCs) have drawn considerable attention as new rising generation of green solvents and organocatalysts. A simple cathodic reduction of C2-H imidazolium based ionic liquids yields, in mild conditions, a RTIL-NHC medium, i.e. a green solvent-derived catalyst system, able to trigger different NHC-catalyzed organic reactions. To verify the versatility of this medium, its efficiency has been tested in different reactions, i.e.: benzoin condensation, Stetter reaction, synthesis of gamma-butyrolactones, synthesis of esters, Henry reaction, Staudinger reaction. In any case, after the addition of the suitable substrates to the electrogenerated RTIL-NHC systems, the products have been isolated in good to elevated yields.