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Vol 55, No 1 (2019)
- Year: 2019
- Articles: 17
- URL: https://journal-vniispk.ru/1070-4280/issue/view/13619
Article
Amino-Modified Silica-Supported Copper-Palladium Alloy. Synthesis and Use in Selective Hydrogenation of Disubstituted Nitroarenes in a Flow Micro Reactor
Abstract
A copper-palladium catalyst supported on amino-modified silica has been synthesized by chemical reduction. It has been found that submicron particles of a copper-palladium alloy are formed on the silica surface. Unlike commercially available palladium catalysts (Pd/Al2O3, Pd/C, Pd/BaSO4), the synthesized copper-palladium catalyst makes it possible to selectively reduce the nitro group in 3-nitrobenzaldehyde and 1-chloro-4-nitrobenzene.
1-6
High Pressure, Temperature, and Solvent Effects on the Rate of the Diels-Alder Reaction of Furan with N-Phenylmaleimide
Abstract
The effects of temperature, solvent nature, and high pressure on the rate of the Diels-Alder reaction of furan with N-phenylmaleimide were studied. A weak acceleration of the title reaction in proton-donor media was observed in comparison to other cycloaddition and ene reactions. The volumes of activation and reaction coincided within the experimental error, in keeping with the presumed cyclic transition state.
7-10
Supramolecular Catalytic Systems Based on a Cationic Amphiphile and Sodium Polystyrene Sulfonate for Decomposition of Organophosphorus Pollutants
Abstract
A supramolecular catalytic system for hydrolytic decomposition of toxic phosphorus acid esters has been obtained on the basis of a cationic surfactant with a morpholinium head group and sodium polystyrene sulfonate. Self-organization of the new binary catalytic system has been studied by tensiometry, conductometry, pH-metry, spectrophotometry, and dynamic and electrophoretic light scattering, and its aggregation thresholds have been determined. High solubilizing ability of the system with respect to a hydrophobic guest has been revealed. The morpholinium surfactant has been found to accelerate the hydrolysis of phosphonates up to 50 times in comparison to the reaction in water. The apparent hydrolysis rate constant in the presence of the polyelectrolyte decreases threefold due to reduction of the reactant binding constants.
11-16
Synthesis and Biological Activity of Alkane-1,1-diylbis(phosphonates) of Diterpenoid Isosteviol
Abstract
Isosteviol reacted with α,ω-dibromoalkanes to give 19-(ω-bromoahkyl) esters which were treated with tetraethyl methylenebis(phosphonate) to obtain bis(phosphonates) conjugated to the deterpenoid skeleton through a polymethylene spacer. The bis(phosphonates) were converted to the corresponding bis(phosphonic acids) by transformation to trimethylsilyl esters and subsequent methanolysis. One of the synthesized compounds showed a high antimicrobial activity (MIC 3.9 µg/mL) against S. aureus and a high cytotoxicity (IC50 15–18 µM) toward M-HeLa and MCF-7 human cancer cell lines.
17-24
Synthesis of Nanostructured Organosilicon Luminophores Based on Phenyloxazoles
Abstract
A series of nanostructured organosilicon luminophores (NOLs) composed of a central 1,4-bis(5-phenyl-1,3-oxazol-2-yl)benzene (POPOP) acceptor chromophore and various peripheral p-terphenyl and 2,5-diphenyl-1,3-oxazole donor fragments have been synthesized for the first time using van Leusen reaction and direct palladium-catalyzed C-arylation of oxazole ring. Due to different functionalities of the silicon branching centers, NOLs with different donor-acceptor ratios have been obtained. The synthesized structures are expected to possess good optical characteristics for use in photonics and optoelectronics.
25-41
Reaction of Lithium Acylate α-Carbanions with Carbon Tetrachloride
Abstract
Metalation of acetic, butanoic, or 2-methylpropanoic acid with lithium diisopropylamide in tetrahydrofuran under argon gave the corresponding lithium acylate α-carbanions which reacted with carbon tetrachloride at 20–25°C for 2 h to afford butanedioic acid or its 2,3-diethyl and 2,2,3,3-tetramethyl derivatives, as well as the corresponding α-chlorocarboxylic acids and chloroform. A radical mechanism was proposed for the formation of dicarboxylic and α-chlorocarboxylic acids.
42-46
Pyridine—Azepine Structural Modification of 3,4-Dihydro-nor-isoharmine
Abstract
Structural modification of 3,4-dihydro-nor-isoharmine through expansion of the dihydropyridine ring to dihydroazepine was accomplished in two stages including pyridine-azepine recyclization of the quaternized substrate by the action of phenacyl halides and their heterocyclic analogs. The recyclization process can be accompanied by 1,2-migration of the acyl group to give mixtures of 4-acyl-9-methoxy-3-methyl-1,2-dihydroazepino[4,5-b]indoles and their 5-acyl-substituted isomers. Factor influencing the recyclization direction and product ratio were analyzed.
74-82
Convenient Synthesis of Fluorine-Containing 2-Aryl-5H-[1,3,4]thiadiazolo[3,2-a]quinazolin-5-ones
Abstract
An efficient synthetic approach to new fluorine-containing [1,3,4]thiadiazolo[3,2-a]quinazolin-5-ones has been developed on the basis of intramolecular cyclization of N-(N′-benzoylhydrazinecarbothioyl)-benzamides obtained from tetrafluorobenzoyl isothiocyanate and benzohydrazides.
83-86
Trifluoroacetylation of N-Substituted 1H-1,2-Diazaphenalenes of the Naphthalene and Acenaphthene Series
Abstract
The acylation of N-substituted 3-methyl-1H-1,2-diazaphenalenes of the naphthalene and acenaphthene series with trifluoroacetic anhydride gave mono- and diacylated products. Despite the presence of a bulky substituent on the pyrrole type nitrogen atom, the trifluoroacetyl group entered the peri position with respect to that substituent. The product structure was confirmed by X-ray analysis.
87-92
Unsymmetrical 2,6-Di-tert-butyl-Substituted Pyrylo-4-squaraines
Abstract
Triethylammonium salt of pyran semisquaraine reacted with N-methyl-substituted heterocyclic salts to give unsymmetrical di-tert-butyl-substituted squarylium dyes. The effect of the terminal heterocycles on the spectral properties of the obtained dyes was studied, and the electronic structure of squaraines and electronic transitions therein were analyzed by quantum chemical methods.
93-100
New Tetracyclic Spiro-1,2,4-trioxolanes (Ozonides). Synthesis and Mass Spectrometric Study
Abstract
New tetracyclic dispiro-1,2,4-trioxolanes (ozonides) were synthesized by reactions of 5–7-membered alicyclic 1,5-diketones with 30% hydrogen peroxide in diethyl ether or ethanol in the presence of boron trifluoride-diethyl ether complex or a strong mineral acid (HCl, H2SO4, HClO4). Mass spectrometric study of the title compounds under atmospheric pressure chemical ionization revealed specificity of fragment ion decomposition with respect to the ring size, which makes it possible to identify such compounds by their mass spectra.
101-107
Synthesis of Spiro[pyrrole-2,5′-thiazoles] by Heterocyclization of Pyrrolobenzoxazinetriones with Aromatic Aldehyde Thiosemicarbazones
Abstract
3-Aroylpyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones regioselectively reacted with semicarbazones derived from aromatic aldehydes to give substituted spiro[pyrrole-2,5′-thiazoles] whose structure was confirmed by X-ray analysis.
108-114
Review
Transformations of Peroxide Products of Alkene Ozonolysis
Abstract
The review summarizes the data published over the past decade on the transformations of peroxide products of alkene ozonolysis, such as cleavage reactions and reactions with reducing agents and nitrogen-containing compounds, as well as on the use of these transformations in directed syntheses.
47-73
Short Communications
1,4-Diphenyl-5H-[1,2,5]triazepino[5,4-a]benzimidazole—A New Heterocyclic System. Synthesis and Properties
Abstract
The first representative of a new heterocyclic system, 1,4-diphenyl-5H-[1,2,5]triazepino[5,4-a]-benzimidazole, has been synthesized by condensation of ethyl (2-benzoyl-1H-benzimidazol-1-yl)acetate with hydrazine hydrate, followed by thermal heterocyclization of intermediate bis-hydrazone.
115-117
Some Peculiarities of the Reduction of Di- and Trichlorocyclopentenones
Abstract
The hydrogenation of 5-allyl- and 5-(2-methylbut-3-en-2-yl)-2,3,5-trichlorocyclopentenones in methanol in the presence of 10% Pd/C is accompanied by exhaustive dechlorination with the formation of 3-propyl- and 3-(2-methylbutan-2-yl)cyclopentane-1,2,4-triones.
118-120
121-123
Convenient Synthesis of Polyfunctional Diphosphonium Salts Based on 2-Methyl-1,4-naphthoquinone
Abstract
An efficient procedure has been proposed for the synthesis of new 1,4-dioxo- and 1,4-dihydroxynaphthyl-substituted diphosphonium salts from 2-methyl-1,4-naphthoquinone and alkane-α,ω-diylbis(diphenylphosphonium) bis(trifluoroacetates). The structure of the products was determined by NMR spectroscopy.
124-127