Russian Chemical Bulletin最新文献

Information entropy is widely used in discrete mathematical chemistry as the descriptor to quantify the structural complexity of molecules. This review covers opportunities to use the information entropy parameters to evaluate changes in the complexity of molecules in both simple and multi-step chemical reactions.

Spiropyran containing a propylammonium moiety at the nitrogen atom in the indoline part of molecule was synthesized. Its photochromic behavior, spectral and photoluminescent properties in water, as well as cytotoxicity towards epidermoid carcinoma A431 cells were estimated. The synthesized compound exhibited positive photochromism and high stability towards photodegradation, and is capable of photoluminescence.

Titanium dioxide synthesis and modification by chemical, electrochemical, and mechanochemical methods are briefly outlined. The atomistic structure, nanostructure, morphology, optical characteristics, functional properties, and peculiar features of the semiconductor material are described. Practical applications of titanium dioxide in catalysis, sorption, and biomedicine are described.

A series of bispidine conjugates bearing monoterpene moieties and either l-proline or l-phenylalanine residues was synthesized. The synthesized bispidines can catalyze asymmetric ethylation of benzaldehydes with diethylzinc. The highest enantioselectivity of the addition reaction (ee 24%) was achieved for bispidine with (–)-α-pinene and Boc-l-proline moieties.

Using triterpenoid betulin as an example, a convenient method for the synthesis of 5,6-dihydropyran derivatives containing a nor-triterpenoid fragment at position 4 was proposed. The method involves the reaction of lupane triterpenoids with paraformaldehyde in dioxane in the presence of sulfuric acid. Approaches to the synthesis of triterpene derivatives of 5,6-dihydropyran-2-one and penta-2,4-dienoic acid were developed based on the obtained 4-(3,28-diacetoxy-20,29,30-tri-nor-lupan-19-yl)-5,6-dihydropyran. Triterpene-substituted penta-2,4-dienoic acid heated with triphenylphosphonium triflate formed a quaternary phosphonium salt, which showed cytotoxicity against human cancer cells MCF-7 (breast cancer) and HCT116 (colon cancer) with IC₅₀ 4–19 µmol L⁻¹, with its activity against these cell lines being superior to the activity of the comparison drug camptothecin.

New N,N′-disubstituted perhydrohexaazadibenzo[fg,op]tetracenes with the (R*,R*,R*,R*) configuration of the chiral centers were synthesized by a one-pot catalytic heterocyclization of perhydrotetraazatetracene with formaldehyde and various primary amines as well as by the catalytic recyclization reaction of 1,3,5-trisubstituted 1,3,5-triazinanes with perhydrotetraazatetracene. The structures of all synthesized compounds were confirmed by NMR spectroscopy and high-resolution mass spectrometry.

The review considers several aspects of the synthesis of dendrimers related to the efficient achievement of their mass and high functionality. These are synthetic methods based on a block scheme for the production of dendrimers and click reactions in the processes of dendritic growth. A method for the synthesis of dendrimers, in which their rapid growth and size are achieved through the use of long spacers between branch points, is also considered. In general, all of these approaches are aimed at the formation of highly functional or high molecular weight molecules with a dendrimer structure in a short time.

The applicability of S_N^H and click reactions in the series of 2-amino-5-bromomethyl-3-(ethoxycarbonyl)pyrazine 1-oxide and its derivatives for the synthesis of distant analogs of folic acid and fluorophores was studied. The target products were synthesized in the yields up to 81%, and their structures were proved by ¹H NMR spectroscopy and mass spectrometry.

New optically active arylsulfonamides, including carane-containing streptocide analogs, were synthesized by the reaction of carane amino alcohols with tosyl- and N-acetylsulfanilyl chlorides. Sulfonamide, which was prepared based on (–)-4β-amino-3α-hydroxy-cis-carane, was studied by X-ray diffraction. The synthesized sulfonamides and the starting amino alcohols were evaluated for antimicrobial activity.

A selective one-pot method was developed for the synthesis of 2,4-dialkyl-6-(2-methoxyethyl)pyridines in yields of 70–82% by the reaction of terminal acetylenes with 3-methoxypropionitrile in the presence of EtAlCl₂, Mg, and Cp₂TiCl₂ (10 mol.%).