Organic Dye-Catalyzed, Visible-Light Photoredox Bromination of Arenes and Heteroarenes Using N-Bromosuccinimide

ACS Omega. 2018 Oct 9;3(10):12868-12877. doi: 10.1021/acsomega.8b02320. eCollection 2018 Oct 31.

Abstract

A variety of arenes and heteroarenes are brominated in good to excellent yields using N-bromosuccinimide (NBS) under mild and practical conditions. According to mechanistic investigations described within, the reaction is speculated to proceed via activation of NBS through a visible-light photoredox pathway utilizing erythrosine B as a photocatalyst. A photo-oxidative approach effectively amplifies the positive polarization on the bromine atom of the NBS reagent. This increase in the electrophilic nature of NBS results in drastically reduced reaction times and diversion from competing light-promoted reactive pathways.