Switchable carbo-fluorosulfonylation and hydro-fluorosulfonylation of alkenes enabled by bifunctional fluorosulfonyl radical precursors

Sulfonyl fluorides are highly valuable compounds in the fields of chemical biology, materials science, and drug discovery. In this study, we present a switchable radical functionalization strategy for synthesizing functional alkyl sulfonyl fluorides from unactivated alkenes using readily available enol-derived fluorosulfonates as versatile fluorosulfonylating reagents. A highly regioselective carbo-fluorosulfonylation of various alkenes with enol-derived fluorosulfonates as bifunctional reagents is disclosed, enabling the simultaneous introduction of the fluorosulfonyl and ketone moiety under mild photocatalytic conditions. Additionally, switching to hydro-fluorosulfonylation is also achieved through merging a hydrogen atom transfer process. Mechanistic studies suggest that a visible-light-induced energy transfer pathway is involved in the homolytic cleavage of S–O bond of enol-derived fluorosulfonates.