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 (AgRF)-R-III compounds in aryl-F and aryl-CF3 couplings vs. the one shown by its (CuRF)-R-III and (AuRF)-R-III 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.