Radical Strategies to Activate Organoboron Reagents for Cross‐Coupling Reactions

In organic synthesis, organoboron reagents—especially alkylboronic acids and their pinacol esters (APEs)—have attracted significant attention due to their advantages, including low toxicity, ease of handling, and bench stability. Therefore, they are considered attractive alternatives as radical sources. However, it is quite challenging to generate these carbon radicals directly from boron compounds because of their high oxidation potentials and low Lewis acidity. This minireview focuses on recent advances in this area, in which heteroatom radicals are applied to activate boron compounds to generate carbon radicals. The review is organized according to activation mechanisms: bromine radical‐mediated activation, oxygen radical‐mediated processes, nitrogen radical (aminyl radical) transfer strategies, direct photoexcitation of synthesized borate complexes, and other approaches, including triplet–triplet energy transfer, electron donor–acceptor complex formation, and catechol‐mediated thermal initiation. For each of these approaches, we discuss the underlying mechanism, substrate scope, synthetic utility, current limitations, and future development.