Lewis acid catalyzed benzylic bromination
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Updated: Jul 4, 2026

Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides
Published on: May 26, 2019
Kazutaka Shibatomi1, Yanhua Zhang, Hisashi Yamamoto
1Department of Materials Science, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580, Japan. shiba@tutms.tut.ac.jp
Abstract:
The Lewis acid catalyzed bromination of aromatic side chains was achieved efficiently by using 1,3-dibromo-5,5-dimethylhydantoin (DBDMH) as the bromination reagent under mild conditions. Zirconium(IV) chloride showed the highest catalytic activity for this benzylic bromination. It was revealed that the present Lewis acid catalysis proceeds by the radical-generation pathway. In contrast, Brønsted acids promoted aromatic-ring bromination without any benzylic bromination. Monobromination of tetramethylsilane was also demonstrated with zirconium(IV) chloride and DBDMH to provide the desired product in good yield.
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