Mechanistic Insights into the Regioselective Defluorofunctionalization of Trifluoromethylanilines via Photocatalytic SET: A Combined Experimental and Computational Study

We report a photocatalytic method for the selective defluorofunctionalization of trifluoromethylanilines, enabling the synthesis of structurally diverse difluoromethylene-containing aza-heterocycles with broad functional group tolerance. A wide range of alkenes─including di-, mono-, and cyclic olefins─undergo efficient intramolecular cyclization to furnish complex tricyclic scaffolds. Mechanistic investigations, supported by experimental and computational studies, reveal that the observed regioselectivity in defluorohydrogenation is governed primarily by steric effects. This work expands the toolkit for C-F bond activation and offers valuable insights into the design of fluorinated scaffolds for pharmaceutical and materials applications.