Pyridine-Catalyzed Radical Borylation of Aryl Halides.

A pyridine-catalyzed transition-metal-free borylation reaction of haloarenes has been developed based on the selective cross-coupling of an aryl radical and a pyridine-stabilized boryl radical. Arylboronates were produced from haloarenes under mild conditions. This borylation reaction features a broad substrate scope, operational simplicity, and gram-scale synthetic ability.