A TEMPO catalyzed cross-dihalogenation reaction was established via redox-regulation of the otherwise complex system of dual electrophilic X⁺ reagents. Formally, the ICl, BrCl, I₂ and Br₂ were generated in-situ, which enabled high regio- or stereoselective access to a myriad of iodochlorination, bromochlorination and homo-dihalogenation products with a wide spectrum of functionalities. With its mild conditions and operational simplicity, this method could enable wide applications in organic synthesis, which was exemplified by divergent synthesis of two pharmaceuticals. Detailed mechanistic investigations via radical clock reaction, pinacol ring expansion and Hammett experiments were conducted, which confirmed the intermediacy of halonium ion. In addition, a dynamic catalytic model based on the versatile catalytic role of TEMPO was proposed to explain the selective outcomes.

中文翻译：

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使用双亲电 X+ 试剂进行 TEMPO 调节的区域选择性和立体选择性交叉二卤化

TEMPO 催化的交叉二卤化反应是通过氧化还原调节双亲电 X ⁺试剂的复杂系统而建立的。形式上，ICl的，氯化溴，我₂和Br ₂产生在-原位，这使高区域选择性或立体选择性获得的iodochlorination，bromochlorination和均-二卤化产物无数与功能性的宽光谱。该方法条件温和，操作简单，可广泛应用于有机合成，例如两种药物的发散合成。通过详细的机械调查进行了自由基钟反应、频哪醇扩环和哈米特实验，证实了卤离子的中介作用。此外，提出了一种基于 TEMPO 多功能催化作用的动态催化模型来解释选择性结果。