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Updated: Jan 4, 2026

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Halogen Bond-Catalyzed Friedel-Crafts Reactions of Aldehydes and Ketones Using a Bidentate Halogen Bond Donor
Xuelei Liu1, Shuang Ma1, Patrick H Toy1
1Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong , P. R. of China.
Abstract:
The use of a halogen bond donor to catalyze Friedel-Crafts reactions of indoles with a range of aldehydes and ketones to directly produce bis(indolyl)methanes, including the natural products arsindoline A, arundine, trisindoline, and vibrindole A, is reported. The bidentate catalyst used in these reactions proved to be more effective than a monondentate analogue, a thiourea commonly used as an organocatalyst, and even a trityl cation that has been used previously in the synthesis of bis(indolyl)methanes.
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