- Reactions of bis(silyl-substituted) methyllithium with α-hydrogen- free nitriles into 1,3,5-triazines
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Bis(silyl-substituted) methyllithium has been found to catalyze a conversion of α-hydrogen-free nitriles directly to yield 2,4,6-trisubsituted s-triazines. The generally high yields and relatively mild reaction conditions of this procedure suggest an alternative to other aromatic nitrile cyclotrimerization reactions. Silicotropic rearrangements from C to N or N to N and an unusual elimination of LiCR2R (R=SiMe3, R=SiMe2NMe2) were observed.
- Chen, Xia,Bai, Sheng-Di,Wang, Li,Liu, Dian-Sheng
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- Addition reactions of bis(trimethylsilyl)methyl- and 1-azzallyl-lithium with cyanoamines into triazines or β-diketiminatolithium compounds
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Reactions of bis(trimethylsily)methyl lithium reagent Li[CHR2] (R = SiMe3) and 1-azaallyllithium, [LiN(R)C(But) CHR]2 with cyanoamines R′CN (R' = Me2N, 1-piperidyl or o, p-pyridyl) yielded β-diketiminatolithiums (1, 2, 5, 7, 8) or symmetrically and mixed substituted triazines (3, 4, 6, 9, 10), respectively. The mechanistic pathways involve silicotropic rearrangements from C to N or N to N and an unusual elimination of Li[CHR2]. The complexes 1, 6, 7, and 10 had been characterized by X-Ray diffraction.
- Chen, Xia,Du, Chenxia,Guo, Jian-Ping,Wei, Xue-Hong,Liu, Dian-Sheng
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- Synthesis, Spectra, and Theoretical Investigations of 1,3,5-Triazines Compounds as Ultraviolet Rays Absorber Based on Time-Dependent Density Functional Calculations and three-Dimensional Quantitative Structure-Property Relationship
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A series of 1,3,5-triazines were synthesized and their UV absorption properties were tested. The computational chemistry methods were used to construct quantitative structure-property relationship (QSPR), which was used to computer aided design of new 1,3,5-triazines ultraviolet rays absorber compounds. The experimental UV absorption data are in good agreement with those predicted data using the Time-dependent density functional theory (TD-DFT) [B3LYP/6–311 + G(d,p)]. A suitable forecasting model (R > 0.8, P 0.0001) was revealed. Predictive three-dimensional quantitative structure-property relationship (3D-QSPR) model was established using multifit molecular alignment rule of Sybyl program, which conclusion is consistent with the TD-DFT calculation. The exceptional photostability mechanism of such ultraviolet rays absorber compounds was studied and confirmed as principally banked upon their ability to undergo excited-state deactivation via an ultrafast excited-state proton transfer (ESIPT). The intramolecular hydrogen bond (IMHB) of 1,3,5-triazines compounds is the basis for the excited state proton transfer, which was explored by IR spectroscopy, UV spectra, structural and energetic aspects of different conformers and frontier molecular orbitals analysis.
- Wang, Xueding,Xu, Yilian,Yang, Lu,Lu, Xiang,Zou, Hao,Yang, Weiqing,Zhang, Yuanyuan,Li, Zicheng,Ma, Menglin
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p. 707 - 723
(2018/05/05)
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- The umpolung of substituent effect in nucleophilic aromatic substitution. A new approach to the synthesis of N,N-disubstituted melamines (triazine triskelions) under mild reaction conditions
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By the umpolung of substituent effect 1,3,5-triazines substituted with three dialkylamino groups were prepared under mild reaction conditions by treatment of cyanuric chloride with tertiary amines. Quaternary N-triazinylammonium salts were identified as reactive intermediates activating the triazine ring and strongly promoting the persubstitution of all chlorine atoms. The final degradation of intermediate N-triazinylammonium chlorides proceeded at room temperature or in boiling dichloromethane spontaneously within irreversible evolution of appropriate chloroalkane.
- Kolesinska, Beata,Kaminski, Zbigniew J.
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experimental part
p. 3573 - 3576
(2009/09/08)
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- A practical and easy synthesis of 2,4,6-trisubstituted-s-triazines
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Triflic anhydride was found to be efficient for the cyclotrimerization of dialkylcyanamides under mild conditions. The same reaction can be applied to aryl nitriles and thiocyanates.
- Herrera, Antonio,Martinez-Alvarez, Roberto,Ramiro, Pedro,Chioua, Mourad,Chioua, Rachid
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p. 503 - 505
(2007/10/03)
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- A convenient method for the preparation of some new derivatives of 1,3,5-s-triazine under solvent free condition
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Nucleophilic reactions on cyanuric chloride were carried out under solvent free conditions to give 1,3,5-s-triazine derivatives with excellent yields.
- Azarifar, Davood,Zolfigol, Mohammad Ali,Forghaniha, Ali
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p. 1897 - 1901
(2007/10/03)
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- Reaction of disubstituted cyanamides with formamides under high pressure
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High pressure-assisted co-cyclization of disubstituted cyanamides with formamide or monosubstituted formamides gave 2-amino- or 2-monosubstituted amino-4,6-bis(disubstituted amino)-1,3,5-triazines in one pot.
- Shibuya, Isao,Oishi, Akihiro,Yasumoto, Masahiko
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p. 1659 - 1662
(2007/10/03)
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- 4,6-Bis- and 2,4,6-tris-(N,N-dialkylamino)-s-triazines: synthesis, NMR spectra and restricted rotations
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Syntheses of various symmetrically and non-symmetrically trisubstituted trazines are reported.Dynamic NMR (1H and 13C) experiments demonstrate that 2,4,6-tris(dialkylamino)-s-triazines show correlated rotations of the alkyl groups in the dialkylamino moieties.Unsymmetrical 2-chloro, 2-alkoxy- and 2-aryloxy-4,6-bis(di-n-alkylamino)-s-triazines display two non-equivalent n-alkyl groups, due to the restricted rotation around the Ar-N bonds.
- Katritzky, Alan R.,Oniciu, Daniela C.,Ghiviriga, Ion,Barcock, Richard A.
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p. 785 - 792
(2007/10/02)
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