CuI-catalyzed regioselective hydrothiolation of alkynes: a thiol-free route to ()-β-alkenyl sulfides.

A thiol-free procedure for regioselective preparation of ()-β-alkenyl sulfides a three-component reaction of aryl/alkyl halides, phenylacetylene, and potassium isopropylxanthate in the presence of copper iodide as a catalyst in polyethylene glycol is reported. In this study, a xanthate salt is used as an odorless source of sulfur. The reactions proceed in a one-pot and single-step pathway with the formation of the carbothionate intermediate identified using NMR data as well as exclusively forming the isomer.