Photocatalytic C-H Functionalization of Nitrogen Heterocycles Mediated by a Redox Active Protecting Group

Herein, we report a photocatalytic strategy for the C-H functionalization of saturated azaheterocycles under mild conditions with only one equivalent of starting material. Our strategy is based on a redox active benzamide protecting group that is activated via a halogen-atom transfer (XAT) process to trigger the formation of an alpha-amino radical. This nucleophilic radical intermediate was then engaged in Giese additions and radical cross couplings to afford C-H alkylated and arylated products. Herein, we report a photocatalytic strategy to efficiently access functionalized azaheterocycles starting from one equivalent of an heterocyclic precursor incorporating a redox active benzamide protecting group. Activation of the protecting group triggered an intramolecular 1,5-HAT leading to alpha-aminoradical intermediates that were engaged in Giese additions or radical cross couplings to respectively afford alkylated or arylated products.image