Russian Chemical Bulletin最新文献

The [4π+2π]-cycloaddition of N-phenylmaleimide to 2-tropylcyclohexanone was performed to prepare previously unknown 9-(2-oxocyclohexyl)-4-phenyl-4-azatetra-cyclo[5.3.2.0^2,6.0^8,10]dodec-11-ene-3,5-dione in 92% yield. The structure of the azacyclic compound was established by modern methods, including 1D and 2D NMR spectroscopy and X-ray diffraction analysis.

It was shown that copolyimides based on adamantane-containing diamine and dianhydrides of 2,3,3′,4′-biphenyltetracarboxylic acid (a-BPDA) and 5,5′-(1,1,1,3,3,3-hexafluoropropane-2,2-diyl)bis(2-benzofuran-1,3-dione) (6FDA) are characterized by good thermal-oxidative properties (T_5% = 465–485 °C) and a high optical transparency (T₄₀₀ = 60–80%) in comparison with copolyimides based on the same dianhydrides and 2,2′-bis(trifluoromethyl)biphenyl-4,4′-diamine (TFBA), containing bulky trifluoromethyl fragments (T₄₀₀ = 38–67%).

The catalysis of direct thiomethylation of 1H-indole and tryptophan under the action of the formaldehyde—mercaptan reagent system in the presence of acids and bases, phosphorus oxide and the oxidative system I₂/NaOH was studied. A mechanism for the catalysis of the multicomponent thiomethylation reaction was proposed based on the results of mass spectrometric study of intermediate compounds.

The physicochemical properties of high-molecular weight compounds based on N,N-diallyl-N′-acyllhydrazines were studied. Based on the results of thermal analysis it was established that sorbents are stable up to 160–210 °C; the destruction of the initial N,N-diallyl-N′-acyllhydrazines starts at lower temperatures. The stability of sorbents in various media, the values of static exchange capacities for hydrogen ions and hydroxide ions ((text{SEC}_{rm{H}^{+}}) and (text{SEC}_{text{OH}^{-}})), and isoelectric points of the surface were determined. Samples for further study of the rare earth metals sorption were selected.

The possibility of functionalizing copolymers of 2,2-diallyl-1,1,3,3-tetraethylguanidinium chloride and methacrylic acid with drugs (isoniazid, ampicillin) and amino acids (l-α-alanine, methionine) was demonstrated.

By modifying ring A in the dammarane triterpenoid dipterocarpol, derivatives with isoxazole and 2-cyano-1-ene fragments were synthesized, which showed activity against the influenza A virus (H1N1) with selectivity indices of 19 and 23.

A convenient synthesis of functionalized aminoalkyl organophosphorus compounds bearing 3-, 4- or 5-coordinated phosphorus atom is based on readily available enamines and trivalent phosphorus acid esters. Radical addition of bis(trimethylsiloxy)phosphine to enamines proceeds regioselectively to give aminoalkylphosphonites, and their subsequent functionalization affords various derivatives of the target acids. The nucleophilic addition of hydrospirophosphorane to enamines also proceeds regioselectively to furnish α-aminoalkyl spirophosphoranes containing five-coordinated phosphorus atom. The resulting compounds are of interest as promising biologically active substances and water-soluble ligands.

The reaction of N-(2-oxo-4-phenyl-1,2-dihydropyridin-3-yl)thioureas with hydrogen peroxide in aqueous ethanol proceeded via the oxidation of the sulfur atom and its subsequent replacement with the oxygen atom of pyridin-2-one to give oxazolo[5,4-b]pyridin-2-amines. 7-Phenyloxazolo[5,4-b]pyridin-2-amines were found to be effective luminophores emitting in the violet spectral range with quantum yields up to 0.59, whereas the corresponding thioureas have no luminescent properties.

Sorption of doxorubicin (Dox) on Fe₃O₄ magnetic nanoparticles coated with iron and silicon glycerolates (ISG-MNPs) was studied. The Dox sorption experiments were carried out in water at different concentrations of ISG-MNPs and Dox. The loading efficiency was assessed by UV spectroscopy. It was demonstrated that at an ISG-MNPs concentration of 0.2 wt.%, an increase in the Dox: ISG-MNPs ratio (from 0.20 to 1.55 w/w) leads to a slow increase in the drug loading capacity (LC) from about 3 to 5%; in this case, the loading efficiency (LE) abruptly decreases from 43 to 6%. A decrease in the ISG-MNPs concentration from 1.0 to 0.5 wt.% (at 0.3 wt.% Dox) leads to an increase in LC from 5.0 to 6.7%. In vitro experiments demonstrated dose-dependent cytotoxicity of the synthesized nanomaterial against human rhabdosarcoma (RD) cells, viz., the statistically significant toxicity of Dox-loaded ISG-MNPs was evident for a nanoconjugate solution with a concentration of 10 µg mL⁻¹, and the cell survival in solutions with a concentration of 100 µg mL⁻¹ was 57%.

A new one-pot method for the synthesis of earlier unknown boron-containing adamantane derivatives, spiro[adamantane-2,2′-boriranes], via the catalytic cycloboration of methyleneadamantane with BF₃·THF and RBCl₂·SMe₂ (R is 2-norbornyl and cyclooctyl) in the presence of Cp₂TiCl₂ and Mg (acceptor of halide ions) was developed. The structure of spiro[adamantane-2,2′-boriranes] was elucidated using 1D (¹H, ¹³C, ¹¹B, and ¹⁹F) and 2D (HSQC, HMBC, COSY, and diffusion-ordered (DOSY)) NMR techniques. 1-Fluorosubstituted spiro[adamantane-2,2′-borirane] was identified as a complex with the solvent molecule (THF) according to a comparison of the experimental and calculated ¹¹B NMR chemical shifts and the calculation data for the thermodynamic parameters of complex formation.