Asymmetric Catalysis: Intramolecular Haloamination of Alkenes - A Perspective

Asymmetric intramolecular haloamination of alkenes is a crucial transformation in modern organic and medicinal chemistry. This strategy is able to introduce both halogen and nitrogen atoms simultaneously in a highly efficient and stereospecific manner. Chiral centers and nitrogen-containing rings are allowed to establish concurrently within a molecular framework. This building process is generally initiated by using an appropriate catalytic system that can activate the halogenating reagent. Then, the activated halogen species and the alkene substrate interact to generate a key intermediate that is most typically a halonium ion. Subsequently, a nitrogencontaining group such as an amine, amide, or sulfonamide undergoes an internal nucleophilic attack that leads to the formation of various nitrogen-containing rings. This article provides a few comments on the different asymmetric intramolecular haloamination systems reported in recent literature. This article comments on several typical asymmetric intramolecular haloamination of alkenes systems, and emphasizes the advantages and disadvantages of the stereocontrol mechanisms, expansion of substrate scope, and optimization of reaction conditions. Looking forward, this article outlines corresponding research directions to address these limitations, suggesting potential methodological approaches.