Alkynes. -1,3-Dipolar cycloaddition of alkynes (I) with azide (II) leads to triazoles whereas the reaction with diazomethane (V) leads to the exclusive formation of pyrazoles. -(RAMA RAO, V. V. V. N. S.; LINGAIAH, B. P. V.; YADLA, R.; SHANTHAN RAO*, P.; RAVIKUMAR, K.; SWAMY, G. Y. S. K.; NARSIMULU, K.; J. Heterocycl. Chem. 43 (2006) 3, 673-679; Fluoroorg. Div., Indian Inst. Chem. Technol., Hyderabad 500 007, India; Eng.) -K. Woydowski 43-023