Abstract: The decarboxylative halogenation of carboxylic acids via radical pathways, initially discovered by Borodine and further developed by Hunsdiecker, represents a classic transformation of carboxylic acid functional groups. The traditional Hunsdiecker reaction involves the pre-preparation of anhydrous silver carboxylate salts, which react with bromine to produce the desired brominated products. Since its inception, the synthetic utility of the Hunsdiecker reaction has attracted significant attention and has been extensively investigated by chemists. Considerable efforts have been directed towards enhancing the efficiency, practicality, and cost-effectiveness of this reaction. In the past decade, a series of novel Hunsdiecker-type reactions have emerged, notably including the recent advancements and innovations made by the group of Prof. Li. This article aims to review the developments in radical decarboxylation and halogenation reactions achieved by chemists in recent years.

Key words: Hunsdiecker reaction, Radical, Decarboxylative halogenation, Organic chemistry