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.