Photoactivation of Electron Donor–Acceptor Complexes for C(sp2)–H Amination of Arenes Using an Organocatalytic Acceptor

This Letter describes the photocatalytic C(sp²)-H amination of electron-rich arenes with azoles via an electron donor-acceptor (EDA) pathway. The acceptor in this system is proposed to be a pyridin-1-ium salt generated in situ from the combination of pyridine and either LiOTf or HOTf. The reactions proceed with irradiation using 370 nm LEDs, and the pyridine/acid acceptor can serve as a catalyst under aerobic conditions. This represents a rare example of a catalytic acceptor in EDA photochemistry.