Vol 61, No 8 (2025)

The heterobimetallic complex [(G^iPr)₂Y(m²-CO)₂MoCp(CO)₂]₂ (1) was obtained by the salt metathesis reaction of equimolar amounts of the yttrium bis-guanidinate chloride complex (G^iPr)₂Y(μ-Cl)₂Li(THF)₂ and Na[CpMo(CO)₃] in a yield of 72%. The reaction of the monoamidinide bisalkyl derivative of yttrium AmdY(CH₂SiMe₃)₂(THF) with two equivalents of molybdenum hydride CpMo(CO)₃H, accompanied by the elimination of SiMe₄, also made it possible to obtain the heterobimetallic complex [AmdY(THF)₂{(m²-CO)MoCp(CO)₂(μ²-CO)MoCp(CO)}₂] (2), the yield of which was 66%. Using the interaction of the naphthalene complex (C₁₀H₈)Yb(THF)₂ with CpMo(CO)₃H in a molar ratio of 1:2 it was shown that the method can also be used to synthesize the heterobimetallic complex of divalent ytterbium [Yb(THF)₄{(m²-CO)MoCp(CO)₃}₂]_n (3). X-ray analysis revealed that complexes 1-3 contain a tetranuclear heterobimetallic skeleton Ln₂Mo₂ in which the Y³⁺ or Yb²⁺ ions are linked to molybdenum ions by bridging isocarbonyl groups, while complex 3 is a coordination polymer.

N-Arylation of several adamantane-containing amines with iodobenzene and its derivatives containing electron-donor and electron-withdrawing groups in para- and meta-positions was studied under catalysis by non-immobilized copper and copper oxide nanoparticles. It was shown that the best yields of the target N-aryl derivatives are achieved using the CuNPs 10/80 nm/rac-BINOL catalytic system when carrying out the reaction in DMSO at 110°C, which turned out to be the most universal. In some cases, it is possible to use other ligands like 2-acetylcyclohexanone and 2-isobutyrylcyclohexanone, as well as DMF as a solvent at 140°C. The maximum yields of N-aryl derivatives exceeded 90%, the dependence of the arylation reaction efficiency on the structure of adamantane-containing amines was shown, however, the effect of substituents in the aryl ring was not so significant. The leaching of copper into the solution during the model reaction was studied, it was shown that the degree of leaching depends on the nature of the ligand used. For comparison purposes, N-heteroarylation of adamantaneamine with trifluoromethyl-substituted 2-bromopyridines was studied, it was found that in this reaction copper leaching occurs to a greater extent. Using TEM, electronegraphy and EDX spectroscopy data, it was shown that 25 nm CuNPs are converted mainly into copper (I) oxide during the reaction, while the average size of the nanoparticles remains virtually unchanged.

Three-component reaction of phenyl-1,3-dicarbonyl compounds with α,β-unsaturated aldehydes and 2-(aminomethyl)aniline under mild conditions leads to regio- and chemoselective formation of trans- and cis-diastereomers of tetrahydro-7H-pyrido[2,1-b]quinazolines. In most cases these products were isolated individually. The spatial structure of the heterocycles was proved based on ¹H, ¹³C, 2D ¹H-¹³C HSQC/HMBC, ¹H-¹H NOESY NMR spectroscopy and X-ray diffraction data.

The one-pot synthesis of functionalized pyrrolo[1,2-c]imidazoles in up to 73% yields via (3+2)-cycloaddition of acylethynylpyrroles with Schiff bases is implemented.

The study of 5,7-dihydroxycoumarins as nucleophilic agents in the S_N ^H reaction with pyrimidines showed that the reaction does not stop at the stage of σ^H-adduct formation as the intermediate in the S_N ^H mechanism, but proceeds further with annulation of the 1,3,5-oxadiazazine ring in moderate to excellent yields. The structures of the obtained compounds were confirmed using NMR and X-ray diffraction. A primary in vitro assessment of antitumor activity was performed.

The article describes the synthesis of potential inhibitors of lactic acid transport proteins (MCT proteins). The key stage of the synthesis is the arylation of pyrazole by the Suzuki reaction. According to the synthetic scheme proposed in the work, a number of target derivatives containing aryl and heteroaryl substituents at position "5" of the pyrazole ring were obtained. The ability to block lactate transport into the cell was assessed for all the derivatives obtained. It was shown that the most promising compound is derivative 3a, containing a chloropyridine fragment at position "5" of pyrazole. Its activity at concentrations of 25 and 50 μM was comparable to the activity of the confirmed MCT1 inhibitor BAY-8002, which was used as a reference compound.

Amberlyst-promoted condensation of 4-benzylsubstituted thieno[3,2-b]pyrrolomethylanols with indole in methylene chloride afforded new 2-[(4-benzyl-4H-thieno[3,2-b]pyrrol-5-yl)methyl]-1H-indoles.

Pyrrole-centered pentaheterocyclic ensembles, tetrasubstituted 1H-pyrroles bearing fundamental heterocycles (pyrrole, furan, thiophene, pyridine) as substituents in various combinations, were synthesized in up to 60% yield by the interaction of hetarylnitriles with ethynylhetarenes in the KOBu^t/DMSO system (room temperature, 1 h). The synthesis is a cascade self-organization of three molecules of ethynylhetarene and one molecule of hetarylnitrile, triggered and driven by acetylenic carbanions.

An effective synthetic approach to (2,2'-bi)pyridines having a fragment of ((9r,10r)-9,10-dihydro-9,10-[1,2]benzenoanthracene-2-yl)amine ((tryptycene-2-yl)amine) in the alpha position via their 1,2,4-triazine precursors has been proposed; the synthesis was made as a result of the nucleophilic ipso substitution of the cyano group at the C5 position of 3-(2-pyridyl)-1,2,4-triazines and the subsequent Bodger reaction with 2,5-norbornadiene.

A method for obtaining azomethine derivatives of pyridine and quinoline series from the corresponding carbaldehyde and amines allowing the synthesis of target products with high yields (more than 85%) is proposed. The methods of GCMS and TG/DSC-MS were used to determine the pathways of thermal destruction of the obtained derivatives, that proceeds via the cleavage of the hydrocarbon substituent from the imine fragment or the entire azomethine fragment and the formation of cationic forms of 3-phenyl-substituted pyridine and 6-substituted quinoline. Using the method of cyclic voltammetry, the electrochemical properties of the obtained compounds have been studied. It was found that electrochemical reduction/oxidation of the obtained compounds are the irreversible processes leading to fragmentation of the molecules of the obtained azomethines.

The interaction of (3-methylfurazanyl)- and (3-aminofurazanyl)amidrazones with 1,2-dicarbonyl compounds (ninhydrin, glyoxal and benzyl) was studied. It was shown that upon using glyoxal, only acyclic products of dimeric structure were formed, while the introduction of other studied 1,2-dicarbonyl compounds into the reaction led to the target (1,2,4-triazin-3-yl)furazans. The structure of the obtained products was confirmed by IR and NMR spectroscopy and X-ray structural analysis. The synthesized biheterocyclic structures are of interest as a platform for the design of pharmacologically active compounds with different spectra of action.

The employment of the PdCl₂/CuCl₂ system facilitates the efficient synthesis of oxobenzochromene derivatives fused to 1,2,3-triazole in good yields. The structure of two of the obtained compounds was confirmed by the X-ray analysis.

It was shown that the reaction of tert-butyl N-(diphenylmethylene)glycinate with 2-methyl-3-{[tert-butyl(dimethyl)silyl]oxy}propanoic acid chloride in CH₂Cl₂ in the presence of Cs₂CO₃ proceeds with the formation of the corresponding β-lactam and an acetylglycine derivative. Under the same conditions, acetyl chloride reacts with tert-butyl N-(diphenylmethylene)glycinate chemoselectively, yielding exclusively tert-butyl ester of acetylglycine.