Hydrogen atom transfer (HAT) which can produce radical intermediates from alkanes provides a strategy to achieve undirected C(sp 3 )‐H functionalization. Typically, primary CH bonds are the least reactive in HAT processes, compared to tertiary CH or activated benzylic CH. It is noteworthy that HAT‐mediated primary CH functionalization has recently been realized through the adjustment of various factors such as the catalyst or reagent design. This review summarizes recent advances in undirected primary CH functionalization via the HAT process. These examples will be discussed according to the HAT reagent. Reaction conditions, primary selectivity of various substrates, mechanism, and origin of the primary selectivity will be highlighted.
Qin et al. (Mon,) studied this question.