2-Ethynylpyridine-Promoted Rapid Copper(I) Chloride Catalyzed Azide-Alkyne Cycloaddition Reaction in Water
Hidekatsu Hiroki, Kenichi Ogata, Shin-ichi Fukuzawa*
*Department of Applied Chemistry, Institute of Science and Engineering, Chuo University, 1-13-27 Kasuga Bunkyo-ku, Tokyo 112-8551, Japan, Email: orgsynthkc.chuo-u.ac.jp
H. Hiroki, K. Ogata, S.-i. Fukuzawa, Synlett, 2013, 24, 843-846.
DOI: 10.1055/s-0032-1318488 (free Supporting Information)
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A catalytic amount of 2-ethynylpyridine promotes the copper(I) chloride catalyzed reaction of azides with alkynes in water at room temperature to afford 1,4-disubstituted 1,2,3-triazoles in good yields. Electron-rich, electron-poor, and sterically crowded substrates can be converted. A study of the additive effect of pyridine derivatives revealed that alkynyl and 2-pyridyl groups were essential for activating the copper catalyst.
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