N-Heterocyclic carbene transition metal complexes for catalysis in aqueous media.

The last decade has seen an increasing number of reports on the use of NHC-metal complexes for catalysis in water, therefore this review is aimed to introduce the whole research on this area, in which the use of water or aqueous/organic media is to be applied. Since the first discovery of the NHC carbenes by Arduengo, work on the synthesis of NHC-metal organometallic compounds has revolutionized the field of catalysis, gradually displacing the typical phosphine and amine-type ligands in view of their higher stability and reactivity. Aqueous catalysis has become a hot topic in Green Chemistry due to the positive implications for the use of water as reaction media.