Publications by authors named "Oleg Sinyashin"

The development of a new Neodymium/Dysprosium metal-organic framework, referred to as Nd/Dy-BTC MOF, based on benzene-1,2,4-tricarboxylic acid, has been achieved through an in situ growth process on 2D transition metal carbides (MXene) surfaces. This synthesis was conducted via a solvothermal method utilizing a solvent mixture of water, ethanol, and dimethylformamide. The primary objective of this research is to investigate the framework's efficacy as a photocatalyst for the degradation of anionic dye, as well as its potential for sensing certain explosives.

View Article and Find Full Text PDF

The presented review systematizes and summarizes the data on the synthesis of pyrrolidine derivatives, which are precursors for obtaining drugs. Based on the analysis of published data, the most promising directions in the synthesis of biologically active compounds containing a pyrrolidine ring are identified. Stereoselective synthesis methods are classified based on the source of the pyrrolidine ring.

View Article and Find Full Text PDF

Presented herein is a novel synthesis of new 2-(quinolin-4-yl)-1,4-dihydroquinazoline systems , in which the acid-catalyzed rearrangement of spiro[benzo[][1,4]diazepine-3,4'-quinolin]-2(1)-ones generated from 3-(2-aminophenyl)-5-benzo[][1,4]diazepin-2(1)-ones with acetone and alkylmethyl ketones has been realized as an important step. An attempt to synthesize isomeric 2-(2-aminophenyl)-5-benzo[][1,4]diazepin-3(4)-one by hydrolysis of the corresponding -{2-[5-benzo[][1,4]diazepin-3(4)-on-2-yl]phenyl}acetamide led to a new heterocyclic system, 6-methyl-8,13-dihydro-13a-quinazolino[4,3-]quinazolin-5-ium 13a-carboxylate , as a result of an unexpected rearrangement. In addition, it is noteworthy that during the hydrolysis of -{2-[5-benzo[][1,4]diazepin-2(1)-on-3-yl]phenyl}acetamides , the not previously described 14-dihydro-5-14,5a-(epimino[1,2]benzo)benzo[5,6][1,4]diazepin[2,1]quinazolin-6(7)-ones were unexpectedly obtained.

View Article and Find Full Text PDF

A family of bifunctional dihetarylmethanes and dibenzoxanthenes is assembled via a reaction of acetals containing a 2-chloroacetamide moiety with phenols and related oxygen-containing heterocycles. These compounds demonstrated selective antitumor activity associated with the induction of cell apoptosis and inhibition of the process of glycolysis. In particular, bis(heteroaryl)methane containing two 4-hydroxy-6-methyl-2-pyran-2-one moieties combine excellent in vitro antitumor efficacy with an IC of 1.

View Article and Find Full Text PDF

The electrophilic activation of various substrates via double or even triple protonation in superacidic media enables reactions with extremely weak nucleophiles. Despite the significant progress in this area, the utility of organophosphorus compounds as superelectrophiles still remains limited. Additionally, the most common superacids require a special care due to their high toxicity, exceptional corrosiveness and moisture sensitivity.

View Article and Find Full Text PDF

The present work explores the specificity of supramolecular assemblies comprising dialkylaminostyrylhetarene dye molecules incorporated into phosphatidylcholine (PC) or phosphatidylserine (PS) aggregates. In PS-based assemblies, the dyes demonstrate a concentration-dependent fluorescent response, distinguishing anionic proteins such as bovine serum albumin (BSA) and pepsin from lysozyme (LYZ) in aqueous solutions. Conversely, no significant response is observed when the dyes are incorporated into the well-organized bilayers of neutral PC.

View Article and Find Full Text PDF
Article Synopsis
  • A new method was created to easily convert spiro[indoline-3,2'-quinoxaline]-2,3'-diones into quinolino[3,4-]quinoxalin-6-ones, using isatines, malononitrile, and 1,2-phenylenediamines under mild conditions.
  • This method is efficient and yields high amounts of the desired compounds, making it useful for creating a diverse range of quinolino[3,4-]quinoxalin-6-ones that could be tested in medicinal chemistry.
  • The researchers also used extensive DFT calculations to study the reaction mechanism in detail.
View Article and Find Full Text PDF

A series of luminescent CuI clusters with stair-step, cubane, and octahedral geometries supported by a novel type of cyclic As,N-ligand, pyridyl-containing 10-phenoxarsines, were synthesized and characterized by NMR spectroscopy, mass spectrometry, elemental analysis, and single-crystal X-ray diffraction analysis. An unusual arrangement of As,N-bidentate and μ-iodo ligands was found in the octahedral cluster. The structural diversity of the Cu(I) complexes is reflected in their photophysical properties: the phosphorescence spectra of the compounds display emission in a broad spectral range of 495-597 nm.

View Article and Find Full Text PDF

Herein, we report a polyphosphoric acid (PPA)-mediated divergent metal-free operation to access a diverse collection of 3-(indol-2-yl)quinoxalin-2-ones and 4-(benzimidazol-2-yl)-3-methylcinnolines in moderate to excellent overall yields. The described process involves two distinct, and competing rearrangements of 3-(methyl(2-phenylhydrazono)methyl)quinoxalin-2-ones, namely [3,3]-sigmatropic Fischer rearrangement with the formation of an indole ring to produce 3-(indol-2-yl)-quinoxalin-2-ones, and Mamedov rearrangement with simultaneous construction of benzimidazole and cinnoline rings to form the new biheterocyclic system─4-(benzimidazol-2-yl)-3-methylcinnolines. The reaction mechanism of both rearrangement channels is explored by extensive dispersion-corrected DFT calculations.

View Article and Find Full Text PDF

The utility of sterically hindered phenols (SHPs) in drug design is based on their chameleonic ability to switch from an antioxidant that can protect healthy tissues to highly cytotoxic species that can target tumor cells. This work explores the biological activity of a family of 45 new hybrid molecules that combine SHPs equipped with an activating phosphonate moiety at the benzylic position with additional urea/thiourea fragments. The target compounds were synthesized by reaction of iso(thio)cyanates with C-arylphosphorylated phenols containing pendant 2,6-diaminopyridine and 1,3-diaminobenzene moieties.

View Article and Find Full Text PDF

The reaction of cyclopentaphosphine cyclo-(P Ph ) (1) with ketones (acetone and cyclooctanone) in the presence of [Mo(CO) (cod)] (cod=cycloocta-1,5-diene) led to air-stable trinuclear complexes in which the bis-phosphanido ligands (PPh-PPh-PPh-PPh-CMe O-PPh) (complex 2) and (PPh-PPh-PPh-PPh-C(CH ) O-PPh) (complex 3) bridge a Mo(CO) -Mo(CO) unit. This extends the reaction of 1 with transition metal carbonyl complexes to further substrates and represents the first examples of insertion of carbonyl compounds into the P-P bond of cyclic oligophosphorus compounds. Complexes 2 and 3 have been characterized by P NMR spectroscopy and single crystal X-ray diffraction.

View Article and Find Full Text PDF

Liposomes modified with tetradecyltriphenylphosphonium bromide with dual loading of α-tocopherol and donepezil hydrochloride were successfully designed for intranasal administration. Physicochemical characteristics of cationic liposomes such as the hydrodynamic diameter, zeta potential, and polydispersity index were within the range from 105 to 115 nm, from +10 to +23 mV, and from 0.1 to 0.

View Article and Find Full Text PDF

Ureas are often thought of as "double amides" due to the obvious structural similarity of these functional groups. The main structural feature of an amide is its planarity, which is responsible for the conjugation between the nitrogen atom and carbonyl moiety and the decrease of amide nucleophilicity. Consequently, since amides are poor nucleophiles, ureas are often thought of as poor nucleophiles as well.

View Article and Find Full Text PDF

Combining two pharmacophores in a molecule can lead to useful synergistic effects. Herein, we show hybrid systems that combine sterically hindered phenols with dinitrobenzofuroxan fragments exhibit a broad range of biological activities. The modular assembly of such phenol/benzofuroxan hybrids allows variations in the phenol/benzofuroxan ratio.

View Article and Find Full Text PDF

Two-dimensional black phosphorus (BP) has emerged as a perspective material for various micro- and opto-electronic, energy, catalytic, and biomedical applications. Chemical functionalization of black phosphorus nanosheets (BPNS) is an important pathway for the preparation of materials with improved ambient stability and enhanced physical properties. Currently, the covalent functionalization of BPNS with highly reactive intermediates, such as carbon-free radicals or nitrenes, has been widely implemented to modify the material's surface.

View Article and Find Full Text PDF

Two-dimensional black phosphorus (BP) has attracted great attention as a perspective material for various applications. The chemical functionalization of BP is an important pathway for the preparation of materials with improved stability and enhanced intrinsic electronic properties. Currently, most of the methods for BP functionalization with organic substrates require either the use of low-stable precursors of highly reactive intermediates or the use of difficult-to-manufacture and flammable BP intercalates.

View Article and Find Full Text PDF

This work presents the synthesis of a new representative of hemicurcuminoids with a nonyloxy substituent () as a fluorescent amphiphilic structural element of vesicular aggregates based on phosphatidylcholine (PC), phosphatidylserine (PS), and 10,12-pentacosadiynoic acid (PCDA). Both X-ray diffraction analysis of the single crystal and H NMR spectra of in organic solvents indicate the predominance of the enol-tautomer of . DFT calculations show the predominance of the enol tautomer in supramolecular assemblies with PC, PS, and PCDA molecules.

View Article and Find Full Text PDF

Tertiary diethylpyridylphosphine was synthesized by the reaction of pyridylphosphine with bromoethane in a suberbasic medium. The reaction of phosphine with the copper(I) iodide led to the formation of a copper(I) coordination polymer, which, according to the X-ray diffraction data, has an intermediate structure with a copper-halide core between the octahedral and stairstep geometries of the CuI clusters. The obtained coordination polymer exhibits a green emission in the solid state, which is caused by the (M+X)LCT transitions.

View Article and Find Full Text PDF

A number of nickel complexes of sodium pectate with varied Ni content have been synthesized and characterized. The presence of the proton conductivity, the possibility of the formation of a dense spatial network of transition metals in these coordination biopolymers, and the immobilization of transition ions in the catalytic sites of this class of compounds make them promising for proton-exchange membrane fuel cells. It has been established that the catalytic system composed of a coordination biopolymer with 20% substitution of sodium ions for divalent nickel ions, Ni (20%)-NaPG, is the leading catalyst in the series of 5, 15, 20, 25, 35% substituted pectates.

View Article and Find Full Text PDF

A conformationally restricted P,N-ligand capable of the design of polynuclear copper(I) complexes was synthesized via the reaction of primary pyridylphosphine, paraformaldehyde, and benzhydrylamine. The reaction of the ligand with copper(I) iodide leads to the tetranuclear copper(I) complex with the octahedral type of copper-iodide core. Different orientation of coordination bonds of the ligands relative to the P,N -heterocyclic fragments and to the Cu I cores leads to the existence of two types of conformers of the complex with "compact" or "stretched" geometry of the Cu I cluster.

View Article and Find Full Text PDF

This review covers nanotherapeutic strategies for solving the global problems associated with Alzheimer's disease (AD). The most dramatic factor contributing humanistic, social and economic urgency of the situation is the incurability of the disease, with the drug intervention addressing only AD symptoms and retarding their progress. Key sources behind these challenges are the inability of the early diagnosis of AD, the lack of comprehensive information on the molecular mechanism of the pathogenesis, the bloodbrain barrier obstacles, and the insufficient effectiveness of currently available drugs and therapeutic strategies.

View Article and Find Full Text PDF

A novel series of 2-(benzimidazol-2-yl)quinoxalines with three types of pharmacophore groups, namely, piperazine, piperidine, and morpholine moieties, which are part of known antitumor drugs, was designed and synthesized. The compounds have been characterized by NMR and IR spectroscopy, high- and low-resolution mass spectrometry, and X-ray crystallography. 2-(Benzimidazol-2-yl)quinoxalines with -methylpiperazine substituents showed promising activity against a wide range of cancer lines, without causing hemolysis and showing little cytotoxicity against normal human Wi-38 cells (human fetal lung).

View Article and Find Full Text PDF

One of the main problems in the treatment of poisoning with organophosphorus (OPs) inhibitors of acetylcholinesterase (AChE) is low ability of existing reactivators of AChE that are used as antidotes to cross the blood-brain barrier (BBB). In this work, modified cationic liposomes were developed that can penetrate through the BBB and deliver the reactivator of AChE pralidoxime chloride (2-PAM) into the brain. Liposomes were obtained on the basis of phosphatidylcholine and imidazolium surfactants.

View Article and Find Full Text PDF

New hybrid liposomes based on cationic amphiphiles with different structures of the head group (cetyltrimethylammonium bromide (CTAB), 3-hexadecyl-1-hydroxyethylimidazolium bromide (IA-16(OH)), 1-(butylcarbamoyl)oxyethyl-3-hexadecylimidazolium bromide (IAC 16(Bu)), and hexadecylmethylpyrrolidinium bromide (PR-16)) were developed for transdermal administration of nonsteroidal anti-inflammatory drugs. The different surfactant/lipid compositions were studied to obtain stable liposomes with high functionality. The hydrodynamic diameter of cationic liposomes was ∼110 nm.

View Article and Find Full Text PDF

New 1-cetyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide complexes with copper(II) bromide and lanthanum(III) nitrate were characterized using dynamic light scattering and transmission electron microscopy, with self-assembly and the morphological behavior elucidated.

View Article and Find Full Text PDF