Related Experiment Video
Updated: Jun 10, 2025

Photogeneration of N-Heterocyclic Carbenes: Application in Photoinduced Ring-Opening Metathesis Polymerization
Published on: November 29, 2018
Photoinduced Vitamin-B12-Catalyzed meta-C-H Bromination/Chlorination of Phenol Derivatives Assisted by a U-Shaped
Weiya Zhang1, Xianghui Zhu1, Huixin Tong1
1School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, P. R. China.
Abstract:
A photoinduced vitamin-B12-catalyzed meta-C-H bromination/chlorination of phenol derivatives was established using a nitrile directing template and N-bromosuccinimide (NBS)/N-chlorosuccinimide (NCS) as halogenated reagents, and a series of meta-bromination/chlorination products were obtained in yields of 51 to 80%. This strategy overcame the selectivity problem of phenols, which have difficulty obtaining meta-products through conventional electrophilic reactions. Furthermore, natural product resveratrol and an intermediate of the γ-secretase inhibitor were successfully synthesized, which demonstrates the practicability of this method.
More Related Videos
Related Concept Videos
Electrophilic Aromatic Substitution: Chlorination and Bromination of Benzene
Reactions at the Benzylic Position: Halogenation
Halogenation of Alkenes
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
Nucleophilic Aromatic Substitution: Elimination–Addition
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
Formation of Halohydrin from Alkenes

