Copper-Catalyzed Late-Stage Benzylic C(sp3)–H Trifluoromethylation

Direct trifluoromethylation of C(sp3)–H bonds, especially in late stages, remains a formidable challenge. Herein, we describe the copper-catalyzed benzylic C(sp3)–H trifluoromethylation. With Cu(I) or Cu(II) as the catalyst, (bpy)Zn(CF3)2 (bpy = 2,2′-bipyridine) as the CF3 source, and NFSI (or Selectfluor) as the oxidant, site-selective benzylic C(sp3)–H trifluoromethylation is successfully implemented in high efficiency under mild conditions....