sulfinylating

Sulfinylating refers to the chemical process of introducing a sulfinyl (‑SO‑) functional group onto an organic substrate, typically converting a carbon–hydrogen or carbon–heteroatom bond into a sulfinyl‑substituted moiety. The transformation is a subset of sulfur‑oxygen chemistry and is often employed to prepare sulfoxides, sulfones, or sulfinyl‑derived heterocycles. In practice, sulfinylation is achieved by reacting a nucleophilic carbon center with a suitable sulfinyl electrophile, such as sulfinyl chlorides (R‑SOCl), N‑sulfinyl imides, or hypervalent sulfur reagents like dimethyl sulfoxide (DMSO) under activation. Common activation methods include the use of Lewis acids (e.g., TiCl₄, BF₃·OEt₂) or catalytic oxidation systems that generate sulfinyl species in situ.

Typical substrates include organometallic reagents (Grignard or organolithium compounds), enolates, and heteroatom nucleophiles (amines, alcohols). For example, the reaction of a phenylmagnesium bromide with methyl sulfinyl chloride yields phenyl‑methyl sulfoxide after work‑up, while the oxidation of a thioether with peracids can proceed via a sulfinylating intermediate en route to a sulfone. In modern synthetic methodology, metal‑catalyzed sulfinylation using sulfinates (RSO₂Na) and electrophilic partners has enabled the construction of sulfinyl‑containing pharmaceuticals and agrochemicals with high regio‑ and stereocontrol.

Historically, early sulfinylation experiments date to the late 19th century, when sulfur dioxide was used to convert alcohols into sulfinic acids. The development of stable sulfinyl reagents in the mid‑20th century expanded the utility of the reaction in organic synthesis. Current research focuses on catalytic, environmentally benign sulfinylation protocols that avoid stoichiometric halogenated reagents, aiming to provide efficient routes to biologically active sulfoxide motifs.