Direct Arene Trifluoromethylation Enabled by a High-Valent Cu~III-CF3 Compound

摘要

Direct C-H trifluoromethylation of arenes and heteroarenes poses an important synthetic challenge that is highly desirable. High-valent Cu~III-CF3 compounds have often been invoked in copper-mediated trifluoromethylation reactions, but the fundamental reactivity toward arenes is elusive. Herein, direct C-H trifluoromethylation of arenes/heteroarenes by a high-valent Cu~III-CF3 compound is disclosed for the first time. The Cu~III-CF3 compound serves CF3 radical and a Cu~II oxidant by homolytic cleavage of a Cu~III-CF3 bond, which engage synergistically in a S_EAr type reaction with arenes. The presence of K2S2O8 co-oxidant can significantly improve the reaction yields. This reaction shows good efficiency, broad functional group tolerance, and the potential in late-stage functionalization. The reactivity of high-valent Cu~III-CF3 compounds disclosed in this study represents an important progress in organo-fluorine and Cu~III chemistry.