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Updated: Jan 13, 2026

Efficient Synthesis of Polyfunctionalized Benzenes in Water via Persulfate-promoted Benzannulation of α,β-Unsaturated Compounds and Alkynes
Published on: December 16, 2019
Metal-free oxidative all-halogen-compatible halogenation of methylenecyclopropane for accessing benzoxazines
Ying-Ying Geng1, Ke-Jiao Li1, Xin-Yue Xie1
1School of Pharmacy, Anhui University of Chinese Medicine, Anhui Academy of Chinese Medicine, Hefei, 230012, China. great7701@ahtcm.edu.cn.
None:
Electrophilic halogenation is a pivotal transformation in organic synthesis, enabling molecular functionalizations that can modulate biological activity. Herein, we report a metal-free oxidative protocol that is compatible with all four major halogens (F, Cl, Br, I) using Selectfluor as a key reagent-either alone for fluorination or in combination with halide salts X- (X = Cl, Br, I) for chlorination, bromination, and iodination. Utilizing readily available methylenecyclopropanes as building blocks, this method efficiently delivers halogenated benzoxazines. This approach is distinguished by its exceptional environmental friendliness, replacing hazardous reagents and heavy metal catalysts with safe, mild conditions. Its practical utility is demonstrated by a scalable and environmentally benign synthesis of the drug etifoxine.
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