The electrophilic halogenation of arenes is perhaps the simplest method to prepare aryl halides, which are important structural motifs in agrochemicals, materials, and pharmaceuticals. However, the nucleophilicity of arenes is weakened by the electron-withdrawing substituents, whose electrophilic halogenation reactions usually require harsh conditions and lead to limited substrate scopes and applications. Therefore, the halogenation of arenes containing electron-withdrawing groups (EWGs) and complex bioactive compounds under mild conditions has been a long-standing challenge. Herein, we describe Brønsted acid-catalyzed halogenation of arenes with electron-withdrawing substituents under mild conditions, providing an efficient protocol for aryl halides. The hydrogen bonding of Brønsted acid with the protic solvent 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) enables this transformation and thus solves this long-standing problem.

中文翻译：

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具有吸电子取代基的芳烃催化亲电卤化

芳烃的亲电卤化可能是制备芳基卤化物的最简单方法，芳基卤化物是农用化学品、材料和药物中的重要结构基序。然而，芳烃的亲核性被吸电子取代基削弱，其亲电子卤化反应通常需要苛刻的条件，导致底物范围和应用受到限制。因此，在温和条件下卤化含有吸电子基团（EWGs）和复杂生物活性化合物的芳烃一直是一个长期的挑战。在此，我们描述了在温和条件下具有吸电子取代基的芳烃的 Brønsted 酸催化卤化，为芳基卤化物提供了一种有效的方案。布朗斯台德酸与质子溶剂 1,1,1,3,3 的氢键，