Photoinduced Transition‐Metal‐Free Chemodivergent Phosphorylation‐Peroxidation and Oxyphosphorylation of Alkenes

A visible‐light‐promoted chemodivergent phosphorylation‐peroxidation and oxyphosphorylation of alkenes with phosphine oxides and HOOtBu was realized under transition‐metal‐free conditions. Using the commercially available Eosin Y as a SET‐photocatalyst, the β‐peroxy‐phosphine oxides were selectively obtained with a catalytic amount of base, while the addition of acid led to the exclusive formation of ꞵ‐keto‐phosphine oxides. Control experiments showed that Eosin Y could also act as a HAT‐catalyst to induce the O‐O bond cleavage of peroxides under acidic conditions.