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1.
N-Bromo and N-chlorosuccinimides add to 1-phenyltricyclo[4.1.0.02,7]heptane in CH2Cl2 with cleavage of the C(1)-C(7) bond to give isomeric 1 : 1 Markownikoff-type endo, anti-adducts of the norpinane structure in a ∼3 :7 ratio corresponding to N and O alkylation of succinimide.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No.2, pp. 457–460, February, 2005 相似文献
2.
L. O. Nindakova N. N. Chipanina V. K. Turchaninov M. V. Ustinov B. A. Shainyan 《Russian Chemical Bulletin》2005,54(10):2343-2347
The reaction of di-μ-chlorobis(1,5-cyclooctadiene)dirhodium with (4S, 5S)-2,2-dimethyl-4,5-bis(methylaminomethyl)-1,3-dioxolane (1) gave the complex [Rh(cod)(1)]Cl (cod is 1,5-cyclooctadiene). The composition of the complexes CoCl2 · L2 and [Rh(cod)(L2)]X (L2 = 1, (4S,5S)-2,2-dimethyl-4,5-bis(aminomethyl)-1,3-dioxolane, and (4S, 5S)-2,2-dimethyl-4,5-bis(dimethylaminomethyl)-1,3-dioxolane; X = Cl, TfO) was studied using IR and 1H NMR spectroscopy. In the RhI cyclooctadienediamine complexes, the diene molecule forms a stronger bond with the metal atom than that in the cyclooctadienediphosphine
analogs.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2270–2274, October, 2005. 相似文献
3.
I. M. Aladzheva O. V. Bykhovskaya P. V. Petrovskii K. A. Lyssenko M. Yu. Antipin T. A. Mastryukova 《Russian Chemical Bulletin》2005,54(11):2635-2641
A facile method was developed for the synthesis of N-(3-phosphonopropyl)-substituted α-amino acids and their phosphine oxide analogs based on hydrolysis of 2-oxo-1,2-azaphospholanes
and 1,2-azaphospholanium salts prepared from readily available reagents. A chelate CuII
N-[(3-diphenylphosphoryl)propyl]glycinate was isolated.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2551–2556, November, 2005. 相似文献
4.
Bromination, acylation, nitration, and metallation of imidazole and pyrrole derivatives containing the difluoromethylene fragment at the N atom were studied. 1-(1,1,2,2-Tetrafluoroethyl)pyrrole, 1-(1,1,2,2-tetrafluoroethyl)imidazole, and 1-(2-chloro-1,1,2-trifluoroethyl)imidazole were used as substrates. 1-Alkyl-3-(1,1,2,2-tetrafluoroethyl)- and 1-alkyl-3-(2-chloro-1,1,2-trifluoroethyl)imidazolium iodides were obtained. These can be used as intermediates for preparation of new ionic liquids of the imidazole series and 1-alkyl-3-polyfluoroethylimidazole-2-thiones.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 781–787, March, 2005. 相似文献
5.
Reactions of N-pyrrolylpotassium with fluorinated electrophiles yielded N-substituted pyrroles containing polyfluoroalkyl, polyfluoroalkenyl, polyfluoroalkylsulfonyl, and polyfluoroaryl substituents.
N-Polyfluoro-substituted pyrroles did not isomerize at ≥100 °C; they were found to be reactive in [4+2] cycloaddition reactions
with perfluorobut-2-yne.
__________
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1890–1895, August, 2005. 相似文献
6.
L. M. Likhosherstov O. S. Novikova A. O. Zheltova V. N. Shibaev 《Russian Chemical Bulletin》2005,54(5):1294-1297
A series of nitrogen-containing physiologically active compounds underwent smooth N-monoalkylation with N-bromoacetyl-β-glycopyranosylamines derived from N-acetyl-D-glucosamine and lactose. This reaction was demonstrated to be promising for the introduction of carbohydrate residues into
heterocyclic compounds, viz., pyridine, imidazole, pyrimidinetrione, carboline, and piperazine derivatives, and into an amino acid, 5-hydroxy-L-tryptophan, which is unstable in alkaline media.
Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday.
__________
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1256–1259, May, 2005. 相似文献
7.
D. A. Chuvashov I. V. Vakulin F. Z. Galin R. F. Talipov 《Theoretical chemistry accounts》2007,118(2):363-369
The effect of temperature and keto ylides structure on preference of their intramolecular cyclization leading to N-containing
heterocyclic compounds or linear products formation has been investigated at the B3LYP/6-31G(d,p) level of theory. It has
been determined that the thermodynamic advantage of the cyclization reactions of ylides increases with temperature, while
Gibbs free energies of linear products formation reactions depend insignificantly on temperature. The Wittig and the Corey–Chaykovsky
reactions are least probable in the case of the sulfonium and ammonium ylides considered. However, for phosphonium ylides
the Wittig reaction must be considerably preferable in comparison with other routes, while behavior of the arsonium ylides
is predicted to be more complex. Research of S-ylides transformations shows that formation of methylthio-substituted heterocycles
with five-, six- or seven- membered rings is possible from a thermodynamic standpoint, while conversion of the corresponding
ylide to a four-membered heterocycle is disadvantageous. Presence of a methyl substituent and its position in the ylide carbon
chain depends ambiguously on the behavior of sulfur keto ylides. 相似文献
8.
Heating of 3-nitro-2-trifluoromethyl-and 3-nitro-2-trichloromethyl-2H-chromenes with indole, N-methylindole, and N-methylpyrrole under solvent-free conditions led with high stereoselectivity and in good yields to cis-trans-3-nitro-2-trifluoromethyl-or trans-cis-3-nitro-2-trichloromethylchromanes substituted by the indol-3-yl (pyrrol-2-yl) fragment in position 4.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1985–1990, October, 2007. 相似文献
9.
A simple and novel method was developed to successfully synthesize N-succinyl-O-carboxymethylchitosan (NSOCMCS) using N-acylation of chitosan with succinic anhydride. The NSOCMCS structure was characterized by Fourier transform infrared and
1H nuclear magnetic resonance. The aggregation behaviors of NSOCMCS were studied using fluorescence spectroscopy, dynamic light
scattering, and atomic force microscopy techniques. The critical aggregation concentration of NSOCMCS in water was determined
to be 0.2–0.3 mg/ml. The apparent hydrodynamic radium of an NSOCMCS aggregate was dependent on the concentration. The aggregates
demonstrated a much swollen association conformation in aqueous solution. The possible aggregation mechanisms for the NSOCMCS
in water are discussed. Moreover, a driving force to form an open aggregation morphology was revealed in this study. Aggregation
behaviors are important physicochemical properties of NSOCMCS, which impact the potential application in the biomedical field. 相似文献
10.
Horia Petride Constantin Drãghici Cristina Florea Aurica Petride 《Central European Journal of Chemistry》2004,2(2):302-322
N-Benzylmorpholine,-piperidine, and-pyrrolidine (1A-C, resp.) are oxidised by RuO4 (generated in situ) at both endocyclic and exocyclic (benzylic) N—α-methylene positions to afford lactams (and dioxo-derivatives) and benzaldehyde (and benzoyl derivatives), respectively.
The N-oxides of 1A-C, formed by a minor side reaction, are not involved as intermediates. Control experiments showed the transient formation of
endo- and exocyclic iminium cations trapped with NaCN as the corresponding nitriles. The proposed course of the RuO4-mediated oxidation of 1A-C involves the consecutive steps 1⇒iminium cations+cyclic enamine⇒oxidation products. The endocyclic/exocyclic regioselectivity of the oxidation reaction lies
between 0.8 (for 1A) and 2.1 (for 1B). The amine cation radical and the N-α-C· carbon-centered radical seem not to be involved. 相似文献
11.
The viscosity of an orthophosphoric acid—N,N-dimethylformamide system was measured in the whole region of compositions at 298–338 K. An excess viscosity of the system
was analyzed by the data obtained using different model concepts. Calculations suggested that strong intermolecular interactions
and the formation of complexes (H3PO4)2·DMF occur in the system.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2252–2256, October, 2005. 相似文献
12.
A. V. Lesiv S. L. Ioffe Yu. A. Strelenko V. M. Danilenko 《Russian Chemical Bulletin》2004,53(10):2233-2240
Coupling of N,N-bis(silyloxy)enamines with tertiary amines and nitrogen-containing heterocycles affording the corresponding functionalized ammonium or iminium salts was studied. The area of its application was determined, and optimal procedures for the synthesis of the target products were proposed. The mechanism including the formation of conjugated nitroso alkene or a silylnitrosonium cation as key intermediates is discussed.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2137–2143, October, 2004. 相似文献
13.
Alexander Konkin Frank Wendler Frank Meister Hans-Klaus Roth Albert Aganov Oliver Ambacher 《Cellulose (London, England)》2007,14(5):457-468
Degradation processes of N-methylmorpholine-N-oxide monohydrate (NMMO), cellulose and cellulose/NMMO solutions were studied by high performance liquid chromatography (HPLC)
and electron spin resonance (ESR) spectroscopy. Kinetics of radical accumulation processes under UV (λ = 248 nm) excimer laser
flash photolysis was investigated by ESR at 77 K. Beside radical products of cellulose generated and stabilized at low temperature,
radicals in NMMO and cellulose/NMMO solutions were studied for the first time in those systems and attributed to nitroxide
type radicals ∼CH2–NO•–CH2∼ and/or ∼CH2–NO•–CH3∼ at the first and methyl •CH3 and formyl •CHO radicals at the second step of the photo-induced reaction. Kinetic study of radicals revealed that formation and recombination
rates of radical reaction depend on cellulose concentration in cellulose/NMMO solutions and additional ingredients, e.g.,
Fe(II) and propyl gallate. HPLC measurements showed that the concentrations of ring degradation products, e.g., aminoethanol
and acetaldehyde, are determined by the composition of the cellulose/NMMO solution. Results based on HPLC are mainly maintained
by ESR that supports the assumption concerning a radical initiated ring-opening of NMMO. 相似文献
14.
A. D. Dubonosov V. P. Rybalkin Ya. Yu. Vorob’eva V. A. Bren’ V. I. Minkin S. M. Aldoshin V. V. Tkachev A. V. Tsukanov 《Russian Chemical Bulletin》2004,53(10):2248-2252
It was shown by electron absorption spectroscopy and X-ray diffraction analysis that steric strains in photochromic 2-(N-acyl-N-arylaminomethylene) benzo[b]thiophen-3(2H)-one molecules ortho-substituted in the N-phenyl ring increase the quantum yield of the N→O photoinduced rearrangement in accord with an increase in the steric constant of the ortho-substituent.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2151–2155, October, 2004. 相似文献
15.
1H NMR spectra in CDCl3 of poly(N-vinylpyrrolidone), epoxidized poly(N-vinyl-pyrrolidone), and products derived from the latter by modification with amino acids (glycine, β-alanine, γ-aminobutyric
acid, and ε-aminocaproic acid) were examined. The 1H NMR spectra of the modified polymers contain signals for water protons due to different centers of water sorption. These
signals differ in chemical shift and integral intensity and indicate a changed spatial packing of the polymer as the result
of its modification.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2377–2380, October, 2005. 相似文献
16.
The structure of galactomannans isolated from seeds of G. delavayi and G. aquatica was studied by 1H and 13C NMR spectroscopy. It was found that the galactomannans consisted mainly of β-1-4-bound mannopyranoses, a part of which was substituted on the C-6 hydroxyl by terminal units of α-galactopyranose.__________Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 12–13, January–February, 2005. 相似文献
17.
A. V. Piskunov A. V. Lado G. A. Abakumov V. K. Cherkasov O. V. Kuznetsova G. K. Fukin E. V. Baranov 《Russian Chemical Bulletin》2007,56(1):97-103
Oxidation of amalgamated magnesium metal with 3,6-di-tert-butyl-o-benzoquinone (1) in different aprotic organic solvents afforded magnesium catecholate and bis-o-semiquinolate complexes. The catecholate derivatives of magnesium CatMgL2 (Cat is the 3,6-di-tert-butyl-o-benzoquinone dianion, L = THF or Py) were synthesized in high yields in pyridine and tetrahydrofuran, respectively. The reactions
in diethyl ether or dimethoxyethane produced hexacoordinated metal bis-o-semiquinolates SQ2MgLn (SQ is the 3,6-di-tert-butyl-o-benzoquinone radical anion, L = Et2O, n = 2; L = DME, n = 1). The reaction with the use of toluene as the solvent gave a magnesium bis-o-semiquinolate complex containing the coordinated unreduced o-quinone molecule. The molecular structures of the [CatMgPy2]2 and SQ2Mg·DME complexes were established by X-ray diffraction.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 92–98, January, 2007. 相似文献
18.
Li-qin Cao Liu-ping Chen Ji-qing Jiao Shu-ying Zhang Wei Gao 《Colloid and polymer science》2007,285(11):1229-1236
Herein, we report a new method that has been developed to prepare thermoresponsive polymers. The white, dry, fine powders
were obtained directly from cross-linking polymerization of N-isopropylacrylamide in supercritical carbon dioxide (scCO2) with N,N-methylenebisacrylamide as a cross-linker. The effects of the reaction pressure and time as well as the initial concentrations
of the initiator, cross-linker, and monomer on the yield and morphology of the resulting polymer were investigated systematically.
The polymer yield was increased with the concentrations of the cross-linker, monomer, and reaction time. Under the condition
of using higher cross-linker concentrations, the cross-linked poly (N-isopropylacrylamide) microparticles with diameters of 50 nm were generated in scCO2 in high-yield and short reaction times. These results suggest that the synthetic method using scCO2 can be used to prepare biomedical materials such as the controlled drug-release system. 相似文献
19.
Isabel Iriepa F. Javier Villasante Enrique Gálvez Antonio Herrera Angel Sánchez Felix H. Cano 《Central European Journal of Chemistry》2005,3(4):683-704
This paper synthesizes N-substituted phthalimides derived from nitrogen heterocycles as potential 5-HT4 ligands by using the Mitsunobu reaction. Conformational studies of some of the new compounds have been conducted using 1H and 13C-NMR spectroscopy. Proton and carbon resonances were achieved through the application of one-dimensional selective NOE, two-dimensional
NMR techniques-homonuclear COSY-45, NOESY and heteronuclear 1H-13C HMQC correlated spectroscopy- and double resonance experiments. The crystal structure of compound 1 was determined by X-ray diffraction. 相似文献
20.
The reactions of 1,4-dimethoxybenzene with azoles (pyrazole, triazole, and their derivatives, as well as tetrazole) were studied
by undivided amperostatic electrolysis at Pt electrodes in MeOH. The process proceeds via the formation of a 1,1,4-trimethoxyarenonium cation as the key intermediate and affords 1,1,4,4-tetramethoxycyclohexa-2,5-diene,
1,1,4-trimethoxy-4-(azol-1-yl)cyclohexa-2,5-diene, and 1,4-dimethoxy-2-(azol-1-yl)benzene as the main products. Azole and
solvent molecules compete as nucleophiles during electrolysis. A fine mechanism of the process was considered.
Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday.
__________
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1166–1171, May, 2005. 相似文献