Cu-Catalyzed Direct C-H Alkylation of Polyfluoroarenes via Remote C(sp3)-H Functionalization in Carboxamides.

A novel dehydrogenative coupling reaction of N-fluorocarboxamides with polyfluoroarenes forming C(sp2)-C(sp3) bonds enabled by copper catalysis has been accomplished. N-Fluorocarboxamides are postulated to undergo copper-mediated dehydrogenative cross-coupling reaction with electron-deficient polyfluoroarenes via a radical pathway. Benzylic C-H bonds and aliphatic C-H bonds in N-fluorocarboxamides could proceed smoothly and demonstrated excellent regioselectivity. The detailed mechanism presented is supported by control experiments and density functional theory calculations.