Cross-Coupling Reactions Enabled by Well-Defined Ag(III) Compounds: Main Focus on Aromatic Fluorination and Trifluoromethylation.

Ag III compounds are considered strong oxidizers of difficult handling. Accordingly, the involvement of Ag catalysts in cross-coupling via 2e - redox sequences is frequently discarded. Nevertheless, organosilver(III) compounds have been authenticated using tetradentate macrocycles or perfluorinated groups as supporting ligands, and since 2014, first examples of cross-coupling enabled by Ag I /Ag III redox cycles saw light. This review collects the most relevant contributions to this field, with main focus on aromatic fluorination/perfluoroalkylation and the identification of Ag III key intermediates. Pertinent comparison between the activity of Ag III R F compounds in aryl-F and aryl-CF 3 couplings vs. the one shown by its Cu III R F and Au III R F congeners is herein disclosed, thus providing a more profound picture on the scope of these transformations and the pathways commonly associated to C-R F bond formations enabled by coinage metals.