Regioselective synthesis of 1,2,3-triazole derivatives via 1,3-dipolar cycloaddition reactions in waterElectronic supplementary information (ESI) available: experimental procedures, elemental analyses and spectroscopic data. See http://www.rsc.org/suppdata/cc/b3/b307084k/

Reaction of an arylacetylene with an azide in hot water gave 1,4-disubstituted 1,2,3-triazoles in high yields, while similar reaction between a terminal aliphatic alkyne and an azide (except m-nitroazidobenzene) afforded a mixture of regioisomers with the ratio of 1,4- to 1,5-isomers ranging from 3 : 1 to 28.6 : 1. Reactions of m-nitroazidobenzene with either arylalkynes or aliphatic alkynes formed only 1,4-disubstituted derivatives in excellent yields.