Amine-Ligated Boryl Radicals Enables Direct C─F Borylation and Cross-Couplings of Polyfluoroarenes

Abstract

Polyfluoroarenes are privileged scaffolds in pharmaceutical and materials science, yet their synthesis remains challenging. Aromatic borylation offers a modular entry point for derivatization via Suzuki–Miyaura cross-coupling, but progress is hindered by two persistent issues: the difficulty of direct borylation on electron-deficient polyfluoroarenes, and the pronounced susceptibility of the resulting boron species to rapid protodeboronation under standard cross-coupling conditions. Here, we present an orthogonal strategy that addresses both limitations. Amine-ligated boryl radicals enable direct radical C─F borylation of polyfluoroarenes under visible-light photoredox catalysis. The resulting amine–borane adducts are crystalline, bench-stable, and resistant to protodeboronation, allowing their direct use in Pd-catalyzed Suzuki–Miyaura cross-couplings. This platform provides scalable and broadly applicable access to functionalized polyfluoroarenes and overcomes some of the synthetic constraints associated with these valuable motifs.