Heterogeneous Iron-Catalyzed Borylation of Aryl Fluorides

We report a mild and practical iron-catalyzed protocol for the borylation of aryl fluorides using commercially available FeCl3, a β-diketiminate ligand, and HBpin as a boron source. The method exhibits broad substrate scope with excellent yields (up to 99%), including non-π-extended fluoroarenes, heterocycles, and substrates with unprotected phenolic OH groups, operating efficiently under ambient to elevated temperatures. Comprehensive mechanistic studies reveal that the reaction proceeds via in situ formation of Grignard intermediates and iron nanoparticles, establishing a heterogeneous catalytic pathway distinct from previous homogeneous systems. This protocol offers a cost-effective, atom-economical route to arylboronates using earth-abundant metal catalysis, significantly expanding the synthetic utility of C-F bond functionalization under mild conditions.