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Copper(I)-Catalyzed Synthesis of Azoles. DFT Study Predicts Unprecedented Reactivity and Intermediates

Fahmi Himo, Timothy Lovell, Robert Hilgraf, Vsevolod V. Rostovtsev, Louis Noodleman,* K. Barry Sharpless* and Valery V. Fokin*

*Department of Molecular Biology, and Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, Email:,,

F. Himo, T. Lovell, R. Hilgraf, V. V. Rostovtsev, L. Noodleman, K. B. Sharpless, V. V. Fokin, J. Am. Chem. Soc., 2005, 127, 210-216.

DOI: 10.1021/ja0471525


Cycloadditions of copper(I) acetylides to azides and nitrile oxides provide ready access to 1,4-disubstituted 1,2,3-triazoles and 3,4-disubstituted isoxazoles, respectively. The process is highly reliable and exhibits an unusually wide scope with respect to both components. Computational studies revealed a nonconcerted mechanism involving unprecedented metallacycle intermediates.

see article for more examples

proposed mechanism (newer mechanistic proposal see click chemistry)

Key Words

Click Chemistry, 1,2,3-Triazoles, Isoxazoles

ID: J48-Y2005-3250