Department of Chemistry, Middle East Technical University, 06531 Ankara, Turkey.
J Org Chem. 2011 Nov 18;76(22):9379-90. doi: 10.1021/jo201685p. Epub 2011 Oct 20.
Synthesis of pyrazoles via electrophilic cyclization of α,β-alkynic hydrazones by copper(I) iodide is described. When treated with copper(I) iodide in the presence of triethylamine in refluxing acetonitrile, α,β-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 α,β-alkynic hydrazones and tolerates the presence of aliphatic, aromatic, and ferrocenyl moieties with electron-withdrawing and electron-donating substituents.
通过碘化亚铜的亲电环化反应合成吡唑。当在回流的乙腈中用碘化亚铜和三乙胺处理时，α，β-炔基腙（可通过腙和丙炔醛和酮制备）发生亲电环化反应，以良好至优异的收率得到吡唑衍生物。该反应似乎对各种α，β-炔基腙具有普遍性，并且耐受具有吸电子和供电子取代基的脂肪族、芳香族和二茂铁部分的存在。
