Electrochemical Difluoromethylarylation of Alkynes.

An unprecedented radical difluoromethylarylation reaction of alkynes has been developed by discovering a new difluoromethylation reagent, CF2HSO2NHNHBoc. This air-stable and solid reagent can be prepared in one step from commercially available reagents CF2HSO2Cl and NH2NHBoc. The CF2H radical, generated through ferrocene-mediated electrochemical oxidation, participates in an unexplored alkyne addition reaction followed by a challenging 7-membered ring-forming homolytic aromatic substitution step to afford fluorinated dibenzazepines.