BINAP-Accelerated Photoinduced Trifluoromethylation of (Hetero)Aryl Iodides

Trifluoromethyl groups hold significance in the bioactivity and physical properties of organic molecules. Contemporary approaches to trifluoromethylated aromatics typically involve the coupling of CuCF₃ reagents with aryl halides, which is limited by the difficulty of oxidative addition of copper to organohalides. Herein, a photoinduced ligand-catalyzed trifluoromethylation/pentafluoroethylation of (hetero)aryl iodides is presented. The conversion of a C─I bond into a C─CF₃ bond is enabled by the photochemistry of copper, which produces aryl radicals with in situ generated CuCF₃ from Ruppert–Prakash reagent under visible light. This radical approach circumvents the challenge of oxidative addition of copper to aryl halides, and a catalytic amount of rac-BINAP substantially accelerates the whole process, allowing the reaction to complete within 1 h under very mild conditions without using any additional photo-redox catalysts. The readily availability of starting material, high efficiency, and broad utility make this transformation attractive for practitioners of synthetic and medicinal chemistry.