Visible-Light Photocatalytic Double C–H Functionalization of Indoles: A Synergistic Experimental and Computational Study
Received: 14 November 2016
Accepted after revision: 26 January 2017
21 February 2017 (eFirst)
Herein is disclosed a novel visible-light photocatalytic double C–H functionalization of indoles. The reaction affords 2,3-difunctionalized indoles in up to 84% yield, but the reaction rate depends strongly on electronic substituent effects. Mechanistic DFT studies and control experiments suggest that the secondary functionalization occurs through an independent photocatalytic oxidation of bromide ions formed during the reaction to generate molecular bromine capable of electrophilic C-3 bromination.