SNAr and C–H Amination of Electron Rich Arenes with Pyridine as a Nucleophile Using Photoredox Catalysis

This report describes the development of two photocatalytic methods for the pyridination of electron rich arenes. First, an SNAr-type reaction between aryl halides and pyridine is developed and optimized. This transformation affords selective substitution of C­(sp2)–halogen over C­(sp2)–OR bonds to afford arylpyridinium products under anaerobic conditions. Under complementary aerobic conditions, analogous substrates are shown to undergo oxidative C­(sp2)–H pyridination.