An efficient and general procedure for the synthesis of alkynyl chalcogenides (selenides and tellurides) by alumina-supported Cu(II)-catalyzed reaction of alkynyl bromides and diphenyl dichalcogenides

Alumina (Al2O3) supported Cu(II) efficiently catalyzes the reaction of alkynyl bromides and diphenyl diselenides and ditellurides in presence of Zn dust or indium(I) bromide to provide the corresponding alkynyl selenides and tellurides. The reactions of a wide variety of substituted alkynyl bromides have been addressed. The zinc dust or InBr is required for the cleavage of diphenyl selenides/tellurides. The mechanism of the reaction is established. The yields of products are high and the catalyst is recycled.