Regioselective synthesis of [1,2,3]-triazoles catalyzed by Cu(I) generated in situ from Cu(0) nanosize activated powder and amine hydrochloride salts

A straightforward and efficient method for the regioselective synthesis of functionalized 1,4-disubstituted [1,2,3]-triazoles, from terminal alkynes and azides, has been established utilizing Cu(0) as the source of the catalytic species. The presumed catalytic Cu(I) species is generated by the combination of 10 mol % copper nanosize activated powder and 1 equiv of an amine hydrochloride salt. The addition of an amine hydrochloride salt into the reaction mixture enhanced the dissolution of copper metal, and subsequently facilitated the formation of the Cu(I)-acetylide intermediate required for the regioselective cycloaddition.