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Updated: Sep 12, 2026

Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts
Published on: February 24, 2015
Visible-light-mediated radical cascade reaction: synthesis of 3-bromocoumarins from alkynoates
Shangbiao Feng1, Jinlai Li, Zaimin Liu
1State Key Laboratory of Applied Organic Chemistry, Department of Chemistry, Lanzhou University, Lanzhou, 730000, China. shexg@lzu.edu.cn.
Abstract:
A visible-light-mediated radical addition of alkynoates to generate 3-bromocoumarins by using N-bromosuccinimide as the bromo source has been accomplished. This procedure provides a bromo radical addition/spirocyclization/ester migration cascade reaction under very mild reaction conditions without using any catalyst or strong oxidant and does not need high reaction temperature. Furthermore, the reaction can also be enlarged to the gram scale, and the product 3-bromocoumarins can be further applied in the synthesis of complex compounds.
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