7721-58-6Relevant academic research and scientific papers
An efficient method for the synthesis of 2-pyridones: Via C-H bond functionalization
Zhou, Shuguang,Liu, Duan-Yang,Wang, Suo,Tian, Jie-Sheng,Loh, Teck-Peng
supporting information, p. 15020 - 15023 (2020/12/23)
A simple and practical method to access N-substituted 2-pyridones via a formal [3+3] annulation of enaminones with acrylates based on RhIII-catalyzed C-H functionalization was developed. Control and deuterated experiments led to a plausible mechanism involving C-H bond cross-coupling and aminolysis cyclization. This strategy provides a short synthesis of structural motifs of N-substituted 2-pyridones.
Structure and tautomerism of azo coupling products from N-alkylenaminones derived from acetylacetone and benzoylacetone in solid phase and in solution
Simunek, Petr,Svobodova, Marketa,Bertolasi, Valerio,Pretto, Loretta,Lycka, Antonin,Machacek, Vladimir
, p. 429 - 438 (2008/02/10)
A series of azo coupling products have been prepared by reaction of substituted benzenediazonium tetrafluoroborates with N-alkyl 4-aminopent-3-en-2-ones or 3-amino-1-phenylbut-2-en-1-ones. The structure and tautomerism of the reaction products were studied by means of single-crystal X-ray study and by NMR spectroscopy in deuteriochloroform solution. The azo coupling products obtained from 4-methylaminopent-3-en-2-ones (3a-i) exist in CDCl3 solution as E/Z isomer mixtures with the Z isomer strongly predominating. The major isomer is a mixture of enamino-azo and imino-hydrazo tautomers with the former predominating. The proportion of the azo form depends on substitution of the benzene ring of the diazonium salt and decreases in the order of MeO > Me > Br > NO2. The position of tautomeric equilibrium is practically unaffected by switching from 4-methylaminopent-3-en- 2-ones to 3-methylamino-1-phenylbut-2-en-1-ones. In the solid phase, the azo form always predominates; substitution of diazonium salt and at N3 nitrogen does not significantly affect the position of the tautomeric equilibrium. The azo coupling products always exist in the form of a single Z isomer. All determined structures, in the solid state, consist of a mixture of the two tautomeric forms, amino-diazenyl and imino-hydrazone, in ratios ranging from 82/18 to 91/9%. The weighed superimposition of both the hydrogen-bonded N1=N2-C1=C2-N3H/ HN1-N2=C1-C2=N3 heterodienic fragments, however, do not allow to clarify the effects of the para-substituents at the N1-phenyl ring both on the N1...N3 hydrogen-bond distances and on the bond lengths in the heterodienic systems within the series 3a-c,f and 4a-c,e,f. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
Synthesis, NMR and X-ray characterisation of 6-substituted 4-amino-5-aryldiazenyl-1-arylpyridazinium salts
?im?nek, Petr,Pe?ková, Markéta,Bertolasi, Valerio,Machá?ek, Vladimír,Ly?ka, Antonín
, p. 8130 - 8137 (2007/10/03)
A new simple method has been used to prepare 6-substituted 4-(subst. amino)-5-aryldiazenyl-1-arylpyridazinium salts from N-methyl- or N-aryl-3-amino-1-phenylbut-2-en-1-ones and 4-aminopent-3-en-2-ones and substituted benzenediazonium tetrafluoroborates or hexafluorophosphates. The structure of selected derivatives was studied by means of 15N NMR spectra and X-ray.
Facile one-pot syntheses of amidines and enamines from oximes via Beckmann rearrangement using trifluoromethanesulfonic anhydride
Takuwa, Tomofumi,Minowa, Tomofumi,Onishi, Jim Yoshitaka,Mukaiyama, Teruaki
, p. 1717 - 1725 (2007/10/03)
Iminocarbocation intermediates were in situ-generated by treating various oximes with trifluoromethanesulfonic anhydride (Tf2O) in the presence of triethylamine in toluene and nucleophilic trapping with amines or sodium enolates under mild conditions afforded the corresponding amidines and enamines. Some of the thus-obtained enamines were converted to 2-substituted 4-oxo-3-quinolinecarboxylic acid derivatives by subsequent intramolecular Friedel-Crafts acylation.
Facile one-pot syntheses of amidines and enamines from oximes via Beckmann rearrangement using trifluoromethansulfonic anhydride
Takuwa, Tomofumi,Minowa, Tomofumi,Onishi, Jim Yoshitaka,Mukaiyama, Teruaki
, p. 322 - 323 (2007/10/03)
Facile one-pot syntheses of amidines and enamines were achieved by trapping carbocation intermediates that were formed by Beckmann rearrangement of oximes with amines and carbon nucleophiles, respectively, under mild conditions.
A new and a convenient route to enaminones and pyrazoles
Stefane, Bogdan,Polanc, Slovenko
, p. 28 - 32 (2007/10/03)
A new method has been developed for the regioselective preparation of enaminones and pyrazoles from 1,3-diketonatoboron difluorides. The reactions proceed smoothly under mild reaction conditions, producing enaminones and pyrazoles in high yields.
The use of K-10/ultrasound in the selective synthesis of unsymmetrical β-enamino ketones
Valduga, Claudete J.,Squizani, Adriana,Braibante, Hugo S.,Braibante, Mara E.F.
, p. 1019 - 1022 (2007/10/03)
p-Phenyl substituted β-enamino ketones 2a-p and cyclic β-enamino ketones 4, 6a-f have been prepared by a selective method by dispersing 1,3- diketones and amines on montmorillonite K-10 under sonication.
RING CLEAVAGE OF N-ALKYLISOXAZOLIUM SALTS BY LITHIUM DIALKYLCUPRATES: SYNTHESIS OF β-ENAMINOKETONES
Alberola, A.,Gonzalez, A. M.,Laguna, M. A.,Pulido, F. J.
, p. 673 - 680 (2007/10/02)
N-Alkylisoxazolium salts undergo ring cleavage when treated with lithium dialkylcuprates to give β-enaminoketones in high yields.
