. The use of halogen bonding interactions as an alternative to acid and metal catalysts for substrate activation has gained popularity in recent years. In this work we demonstrate a halogen bond assisted activation of chalcones under visible light irradiation for the Friedel‐Crafts reaction with indole to yield β‐indolylketones. The simple and scalable protocol uses the readily available CBr4 as halogen bond catalyst. The targets are produced in 31‐94% of yield with excellent functional group tolerance. The proposed mechanism of the reaction is supported by UV‐vis, fluorescence, and NMR spectroscopic studies. Further it is demonstrated that the β‐indolylketones can be oxidised to indole substituted α,β‐unsaturated ketones by DDQ or cyclized to thieno[2,3‐b]indoles in the presence of elemental sulfur and base.

中文翻译：

---

可见光诱导卤素键辅助吲哚和查耳酮的弗里德尔-克来福特反应

。近年来，使用卤素键相互作用作为酸和金属催化剂的替代物来活化底物已变得流行。在这项工作中，我们证明了在可见光照射下卤素键辅助查尔酮的活化，以与吲哚进行弗里德尔-克来福特反应，生成 β-吲哚基酮。简单且可扩展的方案使用现成的 CBr4 作为卤素键催化剂。靶标的产率为 31-94%，具有出色的官能团耐受性。所提出的反应机理得到了紫外-可见光、荧光和核磁共振光谱研究的支持。进一步证明，β-吲哚基酮可以通过DDQ氧化为吲哚取代的α,β-不饱和酮，或在元素硫和碱存在下环化为噻吩并[2,3-b]吲哚。