Photoinduced Vitamin-B-Catalyzed -C-H Bromination/Chlorination of Phenol Derivatives Assisted by a U-Shaped Nitrile Template.

A photoinduced vitamin-B-catalyzed -C-H bromination/chlorination of phenol derivatives was established using a nitrile directing template and -bromosuccinimide (NBS)/-chlorosuccinimide (NCS) as halogenated reagents, and a series of -bromination/chlorination products were obtained in yields of 51 to 80%. This strategy overcame the selectivity problem of phenols, which have difficulty obtaining -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.