Photo-Fenton-Like (Trideutero)methylsulfonylation/Remote (Benzo)thiazolyl Migration Cascade of Unactivated Alkenes with DMSO(-d6).

We report a visible-light photocatalytic, transition-metal-free methylsulfonylation/distal (benzo)thiazolyl migration cascade of unactivated alkenes using DMSO or DMSO-d6 as methylsulfonyl or trideuteromethylsulfonyl sources. The corresponding sulfonyl radicals add selectively to the terminal alkene carbon and trigger distal migration. Mechanistic studies support hydroxyl-radical generation through a photo-Fenton-like process involving water and oxygen, without externally added hydrogen peroxide, thereby avoiding metal leaching and catalyst deactivation.