Photocascade Catalysis: Access to Arene Endoperoxides as Singlet Oxygen Batteries Through Oxyfluoroalkylation and Photooxygenation

The merger of different visible light–driven reactions in one‐pot processes is a powerful strategy for constructing functionalized molecular architectures. In this context, photocascade reactions based on combinations of single‐electron transfer processes (SET–SET), sequences initiated by energy transfer followed by a photoredox step (EnT–SET), and SET–EnT processes have flourished in the literature. However, current approaches involving EnT processes are largely limited to alkene isomerizations. Herein, we report a photocascade transformation that merges photoredox oxyfluoroalkylation with oxygen sensitization via triplet–triplet energy transfer. This strategy enables the formation of functionalized arene endoperoxides from vinyl‐substituted naphthalenes and anthracenes. These endoperoxides subsequently serve as efficient sources of singlet oxygen upon thermolysis. Investigation of the substitution pattern highlights the critical role of functional groups borne by the arene framework.