One-pot, Pd/Cu-catalysed synthesis of alkynyl-substituted 3-ylidene-dihydrobenzo[d]isothiazole 1,1-dioxides

Enyne-substituted benzoisothiazole derivatives have been synthesised under one-pot, operationally simple conditions using 2-iodo-N-(trimethylsilylethynyl)benzenesulfonamides and terminal alkynes as starting materials and a palladium–copper-based catalytic system. The structure of these heterocycles has been demonstrated by NMR spectroscopy and confirmed by X-ray crystallographic analysis. A plausible reaction mechanism has been proposed.