28230-32-2Relevant articles and documents
Bifunctional Phosphine Ligand-Enabled Gold(I)-Catalyzed O-Nucleophilic Addition of N-Hydroxybenzo[1,2,3]-triazin-4(3 H)-ones to Alkynes Followed by [3,3]-Rearrangement: Simultaneous Formation of C-O and C-N Bonds
Xu, Yongcai,Zheng, Kanghe,Zhou, Bingwei,Jin, Hongwei,Liu, Yunkui
, p. 6519 - 6527 (2020)
We describe a gold (I)-catalyzed tandem O-nucleophilic addition/[3,3]-rearrangement reaction of N-hydroxybenzo[1,2,3]-triazin-4(3H)-ones with alkynes enabled by a biphenyl-2-yl phosphine ligand featuring a pendant amide moiety (L1). A variety of 1-(2-oxo-2-arylethyl)benzo [d][1,2,3]triazin-4(1H)-one derivatives were synthesized in good to excellent yields. The present protocol gives a rare example of simultaneous formation of C-O and C-N bonds in the gold(I)-catalyzed [3,3]-sigmatropic rearrangements.
Importance of π-stacking interactions in the hydrogen atom transfer reactions from activated phenols to short-lived N-oxyl radicals
Mazzonna, Marco,Bietti, Massimo,Dilabio, Gino A.,Lanzalunga, Osvaldo,Salamone, Michela
supporting information, p. 5209 - 5218 (2014/06/23)
A kinetic study of the hydrogen atom transfer from activated phenols (2,6-dimethyl- and 2,6-di-tert-butyl-4-substituted phenols, 2,2,5,7,8- pentamethylchroman-6-ol, caffeic acid, and (+)-cathechin) to a series of N-oxyl radical (4-substituted phthalimide-N-oxyl radicals (4-X-PINO), 6-substituted benzotriazole-N-oxyl radicals (6-Y-BTNO), 3-quinazolin-4-one-N-oxyl radical (QONO), and 3-benzotriazin-4-one-N-oxyl radical (BONO)), was carried out by laser flash photolysis in CH3CN. A significant effect of the N-oxyl radical structure on the hydrogen transfer rate constants (kH) was observed with kH values that monotonically increase with increasing NO-H bond dissociation energy (BDENO-H) of the N-hydroxylamines. The analysis of the kinetic data coupled to the results of theoretical calculations indicates that these reactions proceed by a hydrogen atom transfer (HAT) mechanism where the N-oxyl radical and the phenolic aromatic rings adopt a π-stacked arrangement. Theoretical calculations also showed pronounced structural effects of the N-oxyl radicals on the charge transfer occurring in the π-stacked conformation. Comparison of the kH values measured in this study with those previously reported for hydrogen atom transfer to the cumylperoxyl radical indicates that 6-CH3-BTNO is the best N-oxyl radical to be used as a model for evaluating the radical scavenging ability of phenolic antioxidants.
A 15N NMR investigation of a series of benzotriazinones and related antitumour heterocycles
Vaughan, Keith,Wilman, Derry E. V.,Wheelhouse, Richard T.,Stevens, Malcolm F. G.
, p. 300 - 302 (2007/10/03)
A series of 3-substituted 1,2,3-benzotriazin-4-ones, 1 and 2, were synthesized by standard methods and the 15N NMR spectra were recorded. All spectra were obtained using the natural abundance of the nitrogen-15 isotope. The chemical shifts appear in the normal range for N-1, N-2 and N-3 of the triazine ring, and also correlate with the chemical shifts in the spectra of the imidazolotriazinone, 4, and the imidazolotetrazinone, 5. Significantly, the spectra of 1a, 2 and 4, recorded with full NOE, show inversion of the singlet assigned to N-3, demonstrating that these compounds exist in the tautomeric form shown. The structure of the 4-iminobenzotriazinone (3) was confirmed by this 15N NMR analysis. The spectrum shows a signal for the NH-bearing imino-nitrogen atom, which is an inverted singlet in the NOE spectrum, whereas the signal from the N-3 atom of 3 is not inverted in the NOE spectrum. Copyright
