Vol 59, No 9 (2023)
Articles
Silicon analogues of unsaturated hydrocarbons
Abstract
The proposed communication demonstrates the efforts of researchers undertaken to prove the existence of fundamental analogies in the chemistry of structurally related compounds of carbon and silicon. Stable silicon analogues of ethylene - silenes or silaethylenes R2C=SiR2 - were obtained in 1979, disilynes R2Si=SiR2 - in 1981, and analogues of ethine or acetylene - disilins RSi≡SiR - only in 2004. Moving towards the intended goals, scientists synthesized a number of unique branched (bulky) organic and organosilicon substituents, attached them to silicon atoms, closed them from the action of oxygen and air moisture, and prevented secondary dimerization (oligomerization) reactions. The created steric protection led to the preparation of kinetically stable unsaturated silicon compounds and made it possible to characterize them by IR, NMR, UV-visible spectroscopy, and X-ray diffraction analysis.
Russian Journal of Organic Chemistry. 2023;59(9):1111-1120
1111-1120
Metal-free reductive c-c-coupling between arylboronic acids and 2-(5-iodo-1,2,3-triazolyl)phenols
Abstract
A novel approach to 2-(1-arylalkyl)benzoxazoles via a reaction of arylboronic acids with 2-(5-iodo-1,2,3-triazolyl)phenols has been developed. The key intermediates of the proposed cascade transformation are 2-(1-diazoalkyl)benzoxazoles, entering reductive C-C-coupling with boronic acids. The reaction proceeds under transition-metal-free conditions and affords target compounds in yields up to 67%.
Russian Journal of Organic Chemistry. 2023;59(9):1121-1130
1121-1130
Three-component synthesis of new C3-substituted 5,6-dihydropyrrolo[2,1-a]isoquinolines
Abstract
New C3-substituted 5,6-dihydropyrrolo[2,1- a ]isoquinolines were obtained by a three-component domino reaction of 1-aroyl-3,4-dihydroisoquinolines, dimethylacetylenedicarboxylate, and CH-acids. The transformations proceed under microwave irradiation at 130°C in dry acetonitrile.
Russian Journal of Organic Chemistry. 2023;59(9):1131-1141
1131-1141
Oxidative heterocoupling of α-carbanions of lithium acylates with 1,2-dibromoethane
Abstract
The interaction of pairs of α-carbanions of lithium 2-methylpropanoate, butanoate, pentanoate, hexanoate, heptanoate and phenylacetate, generated from various CH-acids (A-H, B-H) under the action of lithium diisopropylamide in THF, with 1,2-dibromoethane leads to a mixture of products of oxidative homo[2,2,3,3-tetramethyl-, 2,3-diethyl-, 2,3-dipropyl-, 2,3-dibutyl-, 2,3-dipentyl- and 2,3 -diphenylsuccinic acids] and heterocoupling [2,2-dimethyl-3-ethyl-, 2-propyl-3-ethyl-, 2-butyl-3-ethyl-, 2-pentyl-3-ethyl-, 2-phenyl-3 -ethyl-, 2-butyl-3-propyl-, 2-pentyl-3-propyl-, 2-propyl-3-phenyl-, 2-butyl-3-pentyl-, 2-butyl-3-phenyl- and 2 -pentyl-3-phenylsuccinic acids] with a total yield of 83-99%. The selectivity of the formation of homo- and heterocoupling products depends on the structure of the coupled α-carbanions.
Russian Journal of Organic Chemistry. 2023;59(9):1142-1151
1142-1151
Synthesis and antibacterial activity of the cyclic 2-substituted thyenopyrimidin-4-ones by bubbling with hydrochloric gas of cycloalkane[b]-2-(n-acylamino)-3-cyanothiophenes
Abstract
The reaction of acylation of some 2-amino-3-cyanocycloalkane[ b ]thiophenes with chlorides of various carboxylic acids gave the corresponding cycloalkane[ b ]-2-( N -acylamino)-3-cyanothiophenes, bubbling with hydrochloric gas from an alcoholic solution of amidonitriles to obtain cyclic 2-substituted thienopyrimidin-4-ones. The study of the antibacterial activity of the compounds against gram-positive and gram-negative microorganisms showed that most of them exhibit a weak antibacterial effect against staphylococci.
Russian Journal of Organic Chemistry. 2023;59(9):1152-1157
1152-1157
Interaction of Methylenecycloalkanes with BF3·THF Catalyzed by 2TiCl2
Abstract
The Cp2TiCl2-catalyzed interaction of methylenecycloalkanes with BF3·THF in tetrahydrofuran was carried out for the first time with the formation of target 1-fluoro-1-boraspirocarbocycles and also isomerization products of a starting monomer (1-methylcycloalk-1-enes). The structure of reaction products was elucidated using one(1H, 13C Dept, 11B, 19F) and two-dimensional (COSY, HSQC, HMBC) NMR spectroscopy, mass spectrometry combined with quantum-chemical calculations of 13C NMR chemical shifts.
Russian Journal of Organic Chemistry. 2023;59(9):1158-1167
1158-1167
Synthesis and aggregation-induced emission of (z)-6-alkylamino-2-amino-4-(2-aryl-1-cyanovinyl)pyridine-3,5-dicarbonitriles
Abstract
( Z )-6-alkylamino-2-Amino-4-(2-aryl-1-cyanovinyl)pyridine-3,5-dicarbonitriles were obtained by reaction of ( Z )-2-amino-4-(2-aryl-1-cyanovinyl)-6-chloropyridine-3,5-dicarbonitriles with various amines, including biologically active ones. The study of the spectral-luminescent properties showed the solid state fluorescence with a maxima at 472-562 nm and its absence in solutions. An increase in the volume fraction of water in solutions above a certain level caused the appearance of fluorescence due to the formation of aggregates. The enhancement of fluorescence upon addition of the viscous solvent glycerol confirmed the presence of aggregation-induced emission of the synthesized compounds.
Russian Journal of Organic Chemistry. 2023;59(9):1168-1178
1168-1178
Synthesis, docking and biological activity of antimetabolites based on uraciles and 5-substituted 2,6-dimethylpyrimidin-4(3h)-ones
Abstract
5-Substituted 2,4-dimethyl-1,6-dihydropyrimidin-6-ones reacted with aromatic aldehydes to form 5-substituted (Z)-2-(2-aryl)-1-ethenylpyrimidin-6-ones, and in the reaction of 5-(4-fluorobenzyl)-2,6-dimethylpyrimidin-4(3 H )-one with 4-fluorobenzaldehyde, 5-(4-fluorobenzyl)-2,6-bis[( E )-4-fluorostyryl]pyrimidin-4(3 H )-one. Uracil and 5-fluorouracil were alkylated with 4-methoxy-2-chloromethylbenzaldehyde to give 2-[2,4-dioxoand 5-fluoro-2,4-dioxo-3,4-dihydropyrimidine-1(2 H )methyl]-4-methoxybenzaldehydes and are condensed with 5-substituted 2,4-dimethyl-1,6-dihydropyrimidin-6-ones to form 1-{5[( E )-2-(5-butyl-, arylmethyl-4-methyl6-oxo-1,6-dihydro-pyrimidin-2-yl)vinyl]-2-methoxybenzyl}uracil, 5-fluorouracil, and 5-bromouracil. The results of docking studies and data on the antibacterial, antitumor, and antimonoamine oxidase activity of the synthesized compounds are presented.
Russian Journal of Organic Chemistry. 2023;59(9):1179-1192
1179-1192
Circumambulatory migrations of arylazo groups in the systems of pentamethoxycarbonyland pentamethylcyclopentadiene
Abstract
According to quantum chemical calculations CAM-B3LYP/6-311++G(d,p) intramolecular migrations of arylazo groups in 5-arylazo-1,2,3,4,5-pentamethoxycarbonylcyclopentadienes occur by a dissociative mechanism through the intermediate formation of tight ionic pairs with low energy barriers: Δ E ≠ZPE, benzonitrile, 14.0 (Ar = C6H4NO2-4) and 16.5 [Ar = C6H3(NO2)2-2,4] kcal/mol. In 5-arylazo-1,2,3,4,5-pentamethylcyclopentadienes, 1,5-sigmatropic shifts of arylazo groups occur along the perimeter of the five-membered ring in conformers with the exo position of the azo group relative to the cyclopentadiene ring with significantly higher activation barriers: Δ E ≠ZPE, benzonitrile, 30.3 (Ar = C6H4NO2-4) and 27.5 [Ar = C6H3(NO2)2-2,4] kcal/mol. The calculations are in good agreement with the data for these compounds obtained by us earlier by dynamic NMR.
Russian Journal of Organic Chemistry. 2023;59(9):1193-1208
1193-1208
Microwave activation in [FeCl3·6H2O–TfOH] - catalysed reaction of binor-s with organic nitriles
Abstract
An efficient catalytic system, consisting of 20 mol % of FeCl3·6H2O and 20 mol % of trifluoromethanesulfonic acid, for amidation of binor-S in a solution of toluene using organic nitriles under microwave synthesis was developed. Typically the reaction proceeds at 100°C in 15 min.
Russian Journal of Organic Chemistry. 2023;59(9):1209-1216
1209-1216
Kinetics of the diels-alder reaction of 2,5-dimethylfuran with N-phenylmaleimide: high hydrostatic pressure, temperature, and solvent effects
Abstract
The rate constants of the Diels-Alder reaction of 2,5-dimethylfuran (1) with N -phenylmaleimide (2) in 5 solvents in the range of temperature 25-45°C and pressure 1-1000 bar have been determined. Activation enthalpy, entropy, Gibbs free energy and volume parameters have been calculated. The equilibrium constants of the 1 + 2 reaction in benzene in the temperature range 25-55°C have been determined, and the reaction enthalpy and entropy have been calculated.
Russian Journal of Organic Chemistry. 2023;59(9):1217-1222
1217-1222
Iodination of propargylpyrazole in the presence of cadmium (II) acetate
Abstract
This paper describes an efficient synthetic method of iodine addition to the triple bond and substitution of the CH-acid hydrogen atom of propargylpyrazole in the presence of cadmium (II) acetate at room temperature, the role of solvents and the ratio of reagents during iodination are optimized.
Russian Journal of Organic Chemistry. 2023;59(9):1223-1227
1223-1227
Synthesis and discovery of a water-soluble ureid of galodif with succinic acid
Abstract
For the first time, a new acyl ureide of the anticonvulsant and anti-alcohol drug galodif (3-chlorobenzhydryl urea) with succinic acid was obtained and studied. The synthesis was carried out by the acylation of galodif with succinic anhydride in presence of certain acids. Unlike galodif, which is practically insoluble in water, the resulting benzhydryl ureide is soluble in aqueous media and can potentially exhibit greater bioavailability and can be used as a liquid dosage form and prodrug with prolonged action.
Russian Journal of Organic Chemistry. 2023;59(9):1228-1232
1228-1232
Interaction of 3-(2-pyridyl)-1,2,4-triazine-5-carbonitriles with 2-amino-4-aryloxazoles in the absence of water
Abstract
Recently we described the solvent-free interaction of 5-aryl-3-(2-pyridyl)-1,2,4-triazine-5-carbonitriles and 2-amino-4-aryloxazoles to form 4,5-diaryl-3-hydroxy-2,2'-bipyridine-6-carbonitriles. It turned out that under absolute (anhydrous) conditions this reaction resulted in the formation of two products, namely, the previously described 4,5-diaryl-3-hydroxy-2,2'-bipyridine-6-carbonitriles (yields up to 44%) and 4,5-diaryl-2,2'-bipyridine-6-carbonitriles (yields up to 32%).
Russian Journal of Organic Chemistry. 2023;59(9):1233-1237
1233-1237
Reaction of 2-hydroxy-5-methylacetophenone chalcones with guanidine in the presence of hydrogen peroxide
Abstract
In the presented work, the reaction of two 2-hydroxy-5-methylacetophenone chalcones and guanidine was investigated in the presence of hydrogen peroxide. Depending on the structure of the chalcones a 4.6-diaryl-2-aminopyrimidine or flavanol was obtained. The structures of the obtained products were elucidated by NMR spectroscopy and X-ray crystallography. Reaction route formation of compounds was proposed.
Russian Journal of Organic Chemistry. 2023;59(9):1238-1242
1238-1242