- Tandem dinucleophilic cyclization of cyclohexane-1,3-diones with pyridinium salts
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The cyclization of cyclohexane-1,3-diones with various substituted pyridinium salts afforded functionalized 8-oxa-10-aza-tricyclo[7.3.1.0 2,7]trideca-2(7),11-dienes. The reaction proceeds by regioselective attack of the central carbon atom of t
- Kiamehr, Mostafa,Moghaddam, Firouz Matloubi,Mkrtchyan, Satenik,Semeniuchenko, Volodymyr,Supe, Linda,Villinger, Alexander,Langer, Peter,Laroshenko, Viktor O.
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supporting information
p. 1119 - 1126
(2013/07/19)
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- Pyridinium salts - Versatile reagents for the regioselective synthesis of functionalized thiazocino[2,3-b]indoles by tandem dinucleophilic reactions of thiooxindoles
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The reaction of thiooxindoles with various 2- and 3-substituted pyridinium salts afforded a variety of functionalized thiazocinoindoles. The products have been prepared in good to excellent yields by regioselective dinucleophilic C/S-cyclocondensation of
- Kiamehr, Mostafa,Gormay, Pavel V.,Villinger, Alexander,Langer, Peter,Iaroshenko, Viktor O.,Moghaddam, Firouz Matloubi,Semeniuchenko, Volodymyr
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supporting information
p. 9685 - 9693,9
(2020/08/20)
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- Excellent correlation between substituent constants and pyridinium N-methyl chemical shifts
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Substituents on the pyridinium ring of N-methylpyridinium derivatives, especially those on the 2- or 4-position, have a large effect on the 1H and 13C NMR chemical shifts of the N-methyl group. Reasonable correlations between the chemical shift changes and the resonance substituent constants are observed. The dual substituent parameter approach provides an excellent correlation when a combination of polar and resonance substituent constants is employed.
- Huang, Sha,Wong, Jesse C.S.,Leung, Adam K.C.,Chan, Yee Man,Wong, Lili,Fernendez, Myrien R.,Miller, Amanda K.,Wu, Weiming
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experimental part
p. 5018 - 5020
(2009/12/01)
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- Substituent effects on formation of cation dimers by weak hydrogen bonds in crystals of carbonyl pyridinium salts of ni(dmit)2
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Five 1:1 salts of 3-X-1-methylpyridinium (X = benzoyl, acetyl, methoxycarbonyl, carboxy, and aminocarbonyl; abbreviated as Ben, Ace, Met, Car, and Ami, respectively) cations with a [Ni(dmit)2]- anion ([Ben]+[Ni(dmit)2]- (1), Ace] +[Ni(dmit)2]- (2), [Met]+[Ni(dmit) 2]- (3), [Car]+[Ni(dmit)2] - (4), and [Ami]+[Ni(dmit)2]- (5)) have been synthesized and characterized by single-crystal X-ray analysis and conductivity measurements. In the crystals, three cations 1-3 were found to form dimers by weak C-H...O hydrogen bonds, and the arrangements of cations had a strong relation with the electronic effect of the substituents. The cations of 1-3 formed similar centrosymmetrically associated dimers constructed by weak C-H...O hydrogen bonds, whose geometric parameters had a correlation with the electronic effect of the substituents. A cation of 4 also formed centrosymmetrically associated dimer, but it was made by an O-H...O hydrogen bond as usually observed in the case of carboxylic acid. In contrast with other complex salts, cations of 5 formed one-dimensional structure by C-H...O hydrogen bonding. The conductivities of salts 1, 2, 3, 4, and 5 at room temperature were 1.00 × 10-6, 1.10 × 10-6, 2.86 × 10-6, 9.77 × 10-6, and 8.75 × 10 -7Scm-1, respectively.
- Tomono, Kazuaki,Koyano, Ayako,Morita, Takashi,Miyamura, Kazuo
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experimental part
p. 1152 - 1159
(2009/12/25)
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- Substantial formation of hydrates and hemiacetals from pyridinium ketones
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Pyridinium ketones have been found to exist as hydrates and hemiacetals in considerable amount in aqueous and alcoholic solutions, respectively. The relative position of the pyridinium positive charge has a large effect on the equilibrium constants. The polar substituent constants, σ,* of the pyridinium group substituted at different positions can be estimated from the hydration constants.
- Huang, Sha,Miller, Amanda K.,Wu, Weiming
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scheme or table
p. 6584 - 6585
(2011/02/24)
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- Synthesis of piperidine derivatives by reduction of pyridinium salts
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Piperidine derivatives 1a-e and 2a-f have been prepared by the reduction of 3-and 4-substituted pyridinium salts with NaBH4 in moderate to excellent yields. The reactions regioselectively give 1,2,5,6-tetrahydropyridines, and the yields depend greatly upon the nature of substituents on the phenyl ring and on the nitrogen atom, the nature and the position of the substituents on the pyridyl ring, and the chain length between the aryloxy and the pyridyl groups. Copyright Taylor & Francis Group, LLC.
- Tang, Zilong,Mayrargue, Joelle,Alami, Mouad
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p. 3367 - 3379
(2008/02/13)
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- Kinetics of Quaternization of trans-4-(p- or m-Substituted styryl)pyridines with Methyl Iodide
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Second order rate constants have been measured for the reaction of several trans-4-(p- or m-substituted styryl)pyridines with methyl iodide in nitrobenzene at 30 deg C, 35 deg C, and 40 deg C.Arrhenius parameters as well as enthalpies and entropies of act
- Ananthakrishnanadar, P.,Rajasekaran, K.
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p. 324 - 325
(2007/10/02)
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- COVALENT ADDUCTS FROM 1,3-DISUBSTITUTED PYRIDINIUM SALTS AND PIPERIDINE
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Covalent adducts 3a-f have been isolated from the reaction between piperidine and pyridinium salts 1a-f. 3a-f are stable both in the solid state and in apolar solvents, whereas their fast dissociation back to piperidine and pyridinium ions occurs in aqueous solution.The latter, in the alkaline environment produced by the amine, yields the correspondent pseudobases, which are key intermediates of the subsequent reactions.For instance, the pseudobases from 1a,b can undergo either a ring-opening reaction or a redox process with the corresponding pyridinium cations.
- Moracci, F. Micheletti,Rienzo, B. Di,Tortorella, S.,Liberatore, F.
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p. 785 - 789
(2007/10/02)
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