HFIP‐Assisted Single C−F Bond Activation of Trifluoromethyl Ketones using Visible‐Light Photoredox Catalysis

摘要

Abstract A visible light photoredox catalytic method for the selective cleavage of single strong C?F bond in trifluoromethyl ketones is reported. Single electron reduction of trifluoromethyl ketones generates difluoromethyl radicals which can be engaged in intermolecular C?C bond formation with N‐methyl‐N‐arylmethacrylamides to furnish fluorine‐containing oxindole derivatives in good yields. The reaction shows excellent chemoselectivity with good functional group tolerance under mild conditions. 1,1,1,3,3,3‐Hexafluoroisopropanol (HFIP) as a solvent plays a critical role for the selective single C?F bond cleavage. High‐level DFT calculations are depicted to shed light on the mechanism.