Photoinduced oxidative activation of electron-rich arenes: alkenylation with H2 evolution under external oxidant-free conditions.

The dehydrogenative cross-coupling of arenes and alkenes is a particularly ideal approach for the synthesis of aryl alkenes. Herein, we report a photo-induced C-H/C-H cross-coupling between electron-rich arenes and styrene derivatives using a dual catalytic system containing an acridinium photosensitizer and a cobaloxime proton-reducing catalyst. This catalytic system enables the Csp2-Csp2 bond formation accompanying H2 evolution. Various substituted aryl alkenes can be afforded with good to excellent yields and high β-regioselectivity.