title: Synthesis of pyrazoles via CuI-mediated electrophilic cyclizations of α,β-alkynic hydrazones.
abstract: 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.
authors: Department of Chemistry, Middle East Technical University, 06531 Ankara, Turkey. zora@metu.edu.tr
authors: Metin
authors: M
authors: Zora
authors: Arif
authors: A
authors: Kivrak
mesh_terms: D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D003500:Cyclization; D004583:Electrons; D006834:Hydrazines / Q000737:chemistry*; D007454:Iodides / Q000737:chemistry*; D015394:Molecular Structure; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D006834:Hydrazines; D007454:Iodides; D011720:Pyrazoles; D003300:Copper