Transition‐Metal‐Catalyzed Site‐Selective C−H Halogenation Reactions

Aryl halides are an indispensably important class of compounds owing to their role as precursors in the synthesis of organometallic reagents and nucleophilic substitution reactions. In addition, with the advent of cross-coupling chemistry, the importance of aryl halides has increased tremendously, and they are therefore classified as the core building blocks in organic synthesis. With the recent advances in the area of transition-metal-catalyzed C-H functionalization, metal-catalyzed C-H halogenation has emerged as a modern tool in organic synthesis. This focus review highlights the significant developments in the area of directed C-H halogenation reactions, particularly in the last two years.