Synthesis of Pyrazoles via Cul-Mediated Electrophilic Cyclizations of alpha,beta-Alkynic Hydrazones

2011-11-18
Synthesis of pyrazoles via electrophilic cyclization of alpha,beta-alkynic hydrazones by copper(I) iodide is described. When treated with copper(I) iodide in the presence of triethylamine in refluxing acetonitrile, alpha,beta-alkynic hydrazones, prepared readily from hydrazines and propargyl aldehydes and ketones, undergo electrophilic cyclization to afford pyrazole derivatives in good to excellent yields. The reaction appears to be general for a variety of alpha,beta-alkynic hydrazones and tolerates the presence of aliphatic, aromatic, and ferrocenyl moieties with electron-withdrawing and electron-donating substituents.
JOURNAL OF ORGANIC CHEMISTRY

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Citation Formats
M. Zora, “Synthesis of Pyrazoles via Cul-Mediated Electrophilic Cyclizations of alpha,beta-Alkynic Hydrazones,” JOURNAL OF ORGANIC CHEMISTRY, pp. 9379–9390, 2011, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/47343.