Photocatalysis in aqueous micellar media has recently opened wide avenues to activate strong carbon−halide bonds. So far, however, it has mainly explored strongly reducing conditions, restricting the available chemical space to radical or anionic reactivity. Here, we demonstrate a controllable, photocatalytic strategy that channels the reaction of chlorinated benzamides via either a radical or a cationic pathway, enabling a chemodivergent C−H arylation or N-dealkylation. The catalytic system operates under mild conditions with methylene blue as a photocatalyst and blue LEDs as the light source. Factors determining the reactivity of substrates, their selectivity, and preliminary mechanistic studies are presented.

Alkyl halides are readily available starting materials in various synthetic transformations including Minisci-type C-H functionalization of heteroarenes. The existing methods, however, often require harsh reaction conditions, such as the use of acids, sacrificial electron donors and radical precursors in excess amounts. Herein, we outline recent developments in this field and highlight our efforts for fully catalytic photoredox Minisci-type alkylation supported by non-covalent interactions in mild aqueous conditions.