Selective Single C(sp3)–F Bond Cleavage in Trifluoromethylarenes: Merging Visible-Light Catalysis with Lewis Acid Activation:The conversion of easily available trifluoromethylarenes into aryldifluoromethyl compounds, which are valuable motifs in the pharmaceutical chemistry, is highly atom- and step-economical. However, the single C(sp3)–F bond cleavage of ArCF3 is a great challenge because of the chemical inertness of the C(sp3)–F bond and the difficult selectivity control of monodefluorination. We report here the first example of single C(sp3)–F functionalization of trifluoromethylarenes via visible-light catalysis merged with Lewis acid activation. The method allows good chemoselectivity control and shows good functional group tolerance. Mechanistic studies suggest an in situ-generated borenium cationic species as the key intermediate for C(sp3)–F bond cleavage in this reaction.
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