Synthesis of 1,4,5-trisubstituted-1,2,3-triazoles by copper-catalyzed cycloaddition-coupling of azides and terminal alkynes

Primary, secondary, and aromatic azides undergo 1,3 dipolar cycloaddition-coupling with an excess of alkyne in the presence of Cu(CH3CN)4PF6 as catalyst, N,N,N′-trimethylethylenediamine as ligand, molecular oxygen, and 4-methoxymorpholine N-oxide (NMO) as co-oxidant to afford 1,4,5-trisubstituted-1,2,3-triazoles.