N-Heterocyclic carbene copper-catalyzed direct alkylation of terminal alkynes with non-activated alkyl triflates.

(NHC)-Cu-catalyzed C(sp)-C(sp3) bond formation has been successfully achieved under mild conditions. Nonactivated alkyl triflates, which could be easily derived from alcohols, were utilized as C-O electrophiles. Mechanistic studies suggested that copper acetylide was the active species. Scale-up reactions further demonstrated the practicality and efficiency of the developed strategy.