Redox-active ligand promoted electrophile addition at cobalt.

The reactivity of an electron-rich cobalt complex bearing an o -phenylenediamide ligand with electrophilic CF 3 + and F + sources is reported. These reactions lead to generation of a Co(III)-CF 3 or Co(III)-F complex, promoted by redox-active ligand-to-substrate two-electron transfer. The rate of trifluoromethyl addition at cobalt correlates with the potential difference between the cobalt complex and the CF 3 + source. We present initial demonstrations of radical trifluoromethylation and nucleophilic fluorination of organic substrates, setting the stage for the development of electrocatalytic pathways for these bond-forming reactions.