Divergent Late‐Stage (Hetero)aryl C−H Amination by the Pyridinium Radical Cation

A Perspective on Late-Stage Aromatic C-H Bond Functionalization

Late-stage functionalization of C-H bonds (C-H LSF) can provide a straightforward approach to the efficient synthesis of functionalized complex molecules. However, C-H LSF is challenging because the C-H bond must be functionalized in the presence of various other functional groups. In this Perspective, we evaluate aromatic C-H LSF on the basis of four criteria─reactivity, chemoselectivity, site-selectivity, and substrate scope─and provide our own views on current challenges as well as promising strategies and areas of growth going forward.