1,2,3- and 1,2,4-triazolium salts, pyrazoles, and quinoxalines from diarylnitrilimines and isocyanides: A study of the scope
作者:Dietrich Moderhack、Ali Daoud
DOI:10.1002/jhet.5570400411
日期:2003.7
4-triazolium salts 11 are formed. Compounds 11 with tert-butyl group at the ring are unstable too, giving rise to triazoles 13. Pyrazoleformation (analogues of 14) is completely suppressed when both tert-butyl and aryl isocyanides are used, whereas access to this ring system works best with see-alkyl isocyanides (the influence of substituents of 2 being almost negligible in this case). Formation of quinoxalines
Diarylnitrilimine and arylnitriloxide dipoles react with two 8-hydroxyquinoline substrates to give respectively pyrazolinic and isoxazolinic derivatives. The structure of these newheterocycles was established on the basis of their spectroscopic data and by chemical methods. The inhibition activity of one of these heterocycles was evaluated in vitro against 8 pathogenic μ-organisms.
Regioselective 1,3-dipolar cycloaddition of nitrilimines to 2-methyl-2-vinyl oxirane
作者:Muhammet Yıldırım、Yaşar Dürüst
DOI:10.1016/j.tet.2011.03.017
日期:2011.5
1,3-Dipolarcycloaddition of in situ generated C,N-diaryl nitrilimines to 2-methyl-2-vinyl oxirane gives rise to the regioselective formation of novel 5-(2-methyloxiranyl)-4,5-dihydropyrazole derivatives in moderate to good yields. The structures and stereochemistries of the new cycloadducts were confirmed by spectroscopic/physical methods including X-ray diffraction data.
[3 + 2] cycloaddition of para-quinone methides with nitrile imines under mild conditions has been achieved. The corresponding spiro-pyrazoline-cyclohexadienone products were constructed in good to excellent yields (up to 97% yield) with high regioselectivity. This straightforward protocol exhibits good functional group tolerance and scalability and provides the spiro-pyrazoline-cyclohexadienones.
[3 + 2]-Cycloaddition of <i>in Situ</i> Generated Nitrile Imines and Acetylene for Assembling of 1,3-Disubstituted Pyrazoles with Quantitative Deuterium Labeling
作者:Vladimir V. Voronin、Maria S. Ledovskaya、Evgeniy G. Gordeev、Konstantin S. Rodygin、Valentine P. Ananikov
DOI:10.1021/acs.joc.8b00155
日期:2018.4.6
methodology for the preparation of 1,3-disubstituted pyrazoles from in situ generated nitrile imines and acetylene is reported. The reactions are performed in a simple two-chamber reactor. One part of the reactor is loaded with hydrazonoyl chloride precursors of active nitrile imine species and a base. The other part is used to generate acetylenefrom CaC2 and water. Partitioning of the reactants improves