Sulfonium Salt‐Mediated Dithiocarbamation of Alkynes for Access to Dithiocarbamate‐Containing Z ‐Vinyl Sulfides

A practical and stereoselective method for the synthesis of vinyl sulfides bearing a dithiocarbamate moiety has been developed. The transformation proceeds via a sulfonium salt‐mediated difunctionalization of terminal alkynes using carbon disulfide (CS ₂ ) and amines as readily available dithiocarbamoyl sources. Under optimized conditions, a range of alkynes, amines, and sulfoxides are well tolerated, affording the desired products in moderate to good yields with exclusive regio‐ and Z ‐selectivity. The synthetic utility is demonstrated by gram‐scale reaction and late‐stage functionalization of biologically relevant fragments. Mechanistic studies support the involvement of alkynyl sulfonium salts as key intermediates, with in situ generated dithiocarbamic acid acting as the nucleophile. This work provides the first access to dithiocarbamate‐containing vinyl sulfides, merging two privileged scaffolds in a straightforward one‐pot, two‐step protocol.