Abstract We report that Ru (bpz) 3 2+ Ru (bpz) 3 2+ is an excellent sensitizer for the photooxygenation of aryl cyclopropanes upon irradiation with visible light. The effectiveness of this photocatalyst enables the synthesis of a range of five-membered endoperoxides in excellent yield with quite low (0.5 mol%) catalyst loadings even when standard household light sources are utilized.
