Click chemistry:: Copper clusters catalyse the cycloaddition of azides with terminal alkynes

Air-stable copper nanoclusters are good catalysts in the Cu(I)-catalysed click cycloaddition of azides with terminal alkynes to give 1,4-disubstituted 1,2,3-triazoles. No additional base or reducing agent is required. The reaction kinetics using various copper catalyst types and the function of copper particles in this system are studied and discussed.