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

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.


Synthesis of ferrocenyl quinones
Zora, Metin; Acikalin, S (Elsevier BV, 2003-03-03)
A squarate-based synthesis of ferrocenyl quinones is described. Thermolysis of ferrocenyl-substituted cyclobutenones, prepared from ferrocenyl cyclobutenediones and alkenyllithiums, affords hydroquinones, which furnish, upon oxidation, ferrocenyl quinones. Ferrocenyl cyclobutenediones have been prepared from known cyclo butenediones by nucleophilic addition of ferrocenyllithium followed by hydrolysis, Pd/Cu-cocatalyzed cross-coupling with (tri-n-butylstannyl)ferrocene or Friedel-Crafts alkylation with ferro...
Synthesis of Bishomoinositols and an Entry for Construction of a Substituted 3-Oxabicyclo[3.3.1]nonane Skeleton
BARAN, ARİF; Bekarlar, Merve; Aydin, Gokay; NEBİOĞLU, MEHMET; ŞAHİN, Ertan; Balcı, Metin (2012-02-03)
1,3,3a,7a-Tetrahydro-2-benzofuran was used as key compound for the synthesis of various bishomoinositol derivatives. The diene was subjected to an epoxidation reaction for further functionalization of the diene unit. The bisepoxide obtained was submitted to a ring-opening reaction with acid in the presence of water. Various bishomoinositols were synthesized. However, when the reaction was carried out in the presence of acetic anhydride, a substituted 3-oxabicyclo[3.3.1]nonane skeleton was formed. The mechan...
Synthesis of ferrocene substituted pyrrolidine derivatives via Et2Zn catalyzed 1 3 dipolar cycloaddition reactions of azomethine ylides
Doğan, Özdemir (2001-05-01)
Synthesis of ferrocene substituted pyrrolidine derivatives via diethylzinc catalyzed 1,3-dipolar cycloadditions of azomethine ylides is described. Azomethine ylides were generated from glycine methyl ester and ferrocenecarboxaldehyde by the 'imine tautomerization' method and trapped with dipolarophiles to give the corresponding cycloadducts in reasonable yields and high regio- and stereoselectivity.
Synthesis of 1,2,3,5- tetrasubstituted pyrrole derivatives via 5-exo-dig type cyclization and stereoselective functionalisation of ferrocene derivatives
Kayalar, Metin; Demir, Ayhan Sıtkı; Department of Chemistry (2005)
A convenient and new method for the synthesis of 1,2,3,5-tetrasubstituted pyrrole derivatives starting from 1,3,-dicarbonyl compounds through acid catalyzed cyclization reaction is described. Alkylation of 1,3-dicarbonyl compound with propargyl bromide followed by one step cyclization with the introduction of primary amines in the presence of catalytic amount of triflouroacetic acid (TFA) affords the corresponding pyrrole derivatives in high yields. The investigations on the studies of developing a new meth...
Synthesis and characterization of conducting copolymers of thiophene-3-yl acetic acid cholesteryl ester with pyrrole
Çırpan, Ali; Toppare, Levent Kamil; YAGCI, Y (2002-05-01)
A new polythiophene containing a cholesteryl side chain in the beta-position was chemically polymerised in nitromethane/carbontetrachloride using FeCl3 as the oxidizing agent. Polymerisation was also achieved by constant current electrolysis in dichloromethane. Subsequently, conducting copolymers of thiophene-3-yl acetic acid cholesteryl ester (CM), PCM1 (obtained from chemical polymerisation method) and PCM4 (obtained from constant current electrolysis) with pyrrole were synthesized using p-toluene sulfoni...
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: