Metal-Bound Heteroatom Radicals: Advancing Site-Selective C-H Functionalization

Selective transformation of C-H bonds represents a frontier research area in synthetic chemistry. While the high reactivity of radicals provides an alternative and efficient pathway for C-H bond functionalization, controlling their selectivity─particularly in processes such as site-selective hydrogen atom abstraction (HAA)─remains a long-standing and unresolved challenge in radical chemistry, largely due to the lack of effective regulation strategies. This review deliberately avoids a comprehensive discussion of the field's current state or landmark discoveries in C-H functionalization. Instead, by focusing on recent advances in metal-catalyzed, highly site-selective C-H bond transformations, this Perspective elucidates how metal-bound radicals enable precise hydrogen abstraction for targeted functionalization. This emerging paradigm offers innovative strategies for regulating radical behavior, potentially unlocking novel radical-mediated selective transformations─including but not limited to the precise functionalization of C-H bonds.