Protocol for the Photocatalytic Hydroxyalkenylation of Alkenes Using 1,2‐Bis(phenylsulfonyl)ethylene and Water

We report on a protocol for the hydroxyalkenylation of alkenes using an acridinium photoredox catalyst in combination with 1,2‐bis(phenylsulfonyl)ethylene and water. Using the protocol, alkenes could be converted into the corresponding 1‐phenylsulfonyl‐4‐hydroxyalkenes in good yields. The hydroxyalkenylation involves the nucleophilic hydroxylation of alkene‐derived radical cations to give β‐hydroxyalkyl radicals, which then undergo a radical addition/β‐elimination sequence. The catalytic cycle is likely sustained by electron transfer from the acridine radical to the benzenesulfonyl radical, which is formed via a radical addition/elimination sequence. Hydroxyalkenylation of alkenes with 1,2‐bis(phenylsulfonyl)ethene and water was affected by photocatalytic electron‐transfer protocol using acridinium photocatalyst A.