Amine‐Ligated Boryl Radicals Enables Direct C─F Borylation and Cross‐Couplings of Polyfluoroarenes
Naoki Yasukawa, Waka Okada, Marc Fimm, Rio Kawamura, Ryota Nomura, Tsunayoshi Takehara, Takeyuki Suzuki, Daniele Leonori, Shuichi Nakamura
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.