Solvent-free palladium-catalyzed addition of diaryl dichalcogenides to alkynes

Solvent-free palladium-catalyzed addition of diaryl disulfides and diselenides to terminal alkynes makes it possible to achieve high stereoselectivity and almost 100% yields in approximate to10 min using only 0.1 mol.% catalyst. Both Pd(PPh3)(4) and easily available Pd(OAc)(2) and PdCl2 can be used in the reaction with an excess of triphenylphosphine. The catalyst and triphenylphosphine are readily recycled for repeated use. The study of the mechanism of the solvent-free catalytic reaction indicates that the process involves binuclear palladium complexes.