Direct C-H Bond Borylation of (Hetero)Arenes: Evolution from Noble Metal to Metal Free.

Organoboron compounds are among the most versatile and useful building blocks in modern synthetic chemistry. The past decades have seen impressive developments in the direct C-H bond borylation of (hetero)arenes in which the applied catalysts are shifting from noble metals to metal-free systems. This Highlight gives a brief summary on this evolution and focuses on recent elegant work in this field.