Volume 61, Nº 4 (2025)

The efficiency of copper-containing metal-organic coordination polymers (Cu-MOFs) and commercially available non-immobilized copper nanoparticles (CuNPs) in the amination of 2-iodopyridine, 2-bromo-pyridine and its trifluoromethyl derivatives with n-octylamine and adamantane-containing amines with different steric hindrances at the amino group was compared. The yields of the amination products under optimized conditions were shown to be close for both catalytic systems. To achieve good yields in the case of 2-bromopyridine, an increase in the concentration of reagents and the use of 2 equiv. of haloarene are required, while the introduction of a trifluoromethyl group at position 6 of the pyridine ring improves the yields of the amination products. Increasing steric hindrances at the amino group leads to a noticeable decrease in the yields of products in the Cu-MOF catalyzed reactions. However, the use of CuNPs allows for successful reactions with such amines, and CuNPs of 25 nm average size demonstrated an advantage over bifractional nanoparticles of 10/80 nm. On the other hand, increasing the concentration of reagents in the Cu-MOF catalyzed reactions provides good yields of the target compounds without addition ligands.

The possibility of diastereoselective allylation of (R)-2,3-O-cyclohexylideneglyceraldehyde with methyl 3-[(tributylstannyl)methyl]but-3-enoate and tributyl[2-(2,2-diethoxyethyl)prop-2-en-1-yl]stannane was studied for the first time. The obtained products were used in the synthesis of valuable building blocks – unsaturated lactones (6R)- and (6S)-6-[(2R)-1,4-dioxaspiro[4.5]dec-2-yl]-4-methyl-5,6-dihydro-2H-pyran-2-one, which found application in the preparation of the C¹–C⁸ fragment of amphidinolides of families C and F, the pheromone of the hemlock moth Lambdina athasaria, in the formal synthesis of the pheromone of the pine moth Lambdina pellucidaria and the coffee leaf miner Leucoptera coffeella.

Based on 2-acetylcyclopentanone, the synthesis of various heterocycles has been studied, in particular, derivatives of pyrazole, pyrimidine, condensed systems of pyrazolo[1,5-a]pyrimidine and 1,2,4-triazolo[1,5-a]pyrimidine, as well as their methyl iodides. Due to the observed nuclear Overhauser effect (NOE), in a number of cases, the structure of the synthesized substances could be proven only by using the NOESY NMR spectroscopy technique. An effective method for using NMR spectroscopy to prove the structures of the synthesized substances is proposed, by obtaining their methyl iodides and then studying the spectra of the resulting salts.

Based on the reactions of diastereoselective allylation of (R)-2,3-O-cyclohexylideneglyceraldehyde with methyl 3-(bromomethyl)but-3-enoate and its allylstannyl derivative, unsaturated lactones (6R)- and (6S)-6-[(2R)-1,4-dioxaspiro[4.5]dec-2-yl]-4-methyl-5,6-dihydro-2H-pyran-2-ones were synthesized. After highly diastereoselective reduction, these lactones found application in the implementation of a new retrosynthetic scheme for the preparation of С⁵–С¹⁴, С¹⁵–С¹⁹ and С²⁰–С²⁶ building blocks of amphidinolides of the G and H families.

Upon the interaction of (2E,4E)-5-phenyl-2-cyano-2,4-pentadieneselenoamide with α-bromoketones in DMF under argon (2E,4E)-2-(4-aryl-1,3-selenazole-2-yl)-5-phenylpenta-2,4-diennitriles were obtained with yields 42-71%.

5-Aryl-1Н-pyrrole-2,3-diones react with amidoximes to form enamines with a 1,2,4-oxadiazole fragment, which are potential precursors of a new type of 1Н-pyrrole-2,3-diones. The described reaction is the first example of the recyclization of 4-unsubstituted 5-aryl-1H-pyrrole-2,3-diones under action of 1,4-binucleophilic reagent.

Micellar effects in perhydrolysis and base catalyzed hydrolysis of 4-nitrophenyl esters of phosphoric, phosphonic and toluolsulphonic acids in organized microheterogeneous systems based on dicationic (Gemini surfactant, GS – AlkIm⁺–(CH₂)₃–Im⁺Alk ∙ 2Br^–, Alk = C₁₂H₂₅ or C₁₄H₂₉) and monocationic (AlkIm⁺CH₃ ∙ Br^– , Alk = C₁₂H₂₅ or C₁₄H₂₉) surfactants have been analyzed. The effect of concentration of reagents is the main factor responsible for micellar catalysis. Hydroperoxide α-effect described as second order rate constants ratio for perhydrolysis and base catalyzed hydrolysis remains in organized media, and, depending on surfactant/substrate nature, may amount to ~ 100.

We have found that BDP reacts with 1,3-dibromo-5,5-dimethylhydantoin in sulfuric acid to form 5-bromo-4,5-dihydrobenzo[1,2-c:3,4-c']bis([1, 2,5]oxadiazol)-4-ol, which upon treatment with a base (calcium hydroxide) turns into 1a,7b-dihydrooxireno[2',3':5,6]benzo[1,2-c:3,4-c ']bis([1,2,5]oxadiazole). The structure of the compound was established by X-ray diffraction. The resulting compound exhibits the usual properties of epoxides. Easily adds nucleophiles to form the corresponding alcohols, which, when treated with p-toluenesulfonyl chloride in the presence of tetrabutylammonium bromide and sodium hydroxide in benzene, give functional derivatives of BDF.

Substituted 2,3,4,5,6,7-hexahydro-1-benzofuran-3,3-dicarbonitriles were obtained by three-component condensation of 2-bromodimedone, aromatic aldehydes and malononitrile.

During ozonation of 2-dichloromethyl-5-(1-methylethylidene)-N-[(1R)-1-phenylethyl]cyclopent-3-en-1-carboxamide in a solution of CH₂Cl₂-MeOH (10 : 1) at 0°С and (3aR,6aR)-3-hydroxy-6-(1-methylethylidene)-2-[(1R)-1-phenylethyl)-3,3a,6,6a-tetrahydrocyclopenta[c]pyrrol-1(2H)-one in solution of cyclohexane-MeOH (10 : 1) at 5°С under TLC control until complete consumption of the starting compounds, followed by treatment with Me₂S, new optically active cyclopentenones for cyclopentanoides, 2-dichloromethyl-5-oxo-N-[(1R)-1-phenylethyl]cyclopent-3-ene-1-carboxamide and (3aR,6aR)-3-hydroxy-2-[(1R)-1-phenylethyl]-2,3,3a,6a-tetrahydrocyclopenta[c]pyrrole-1,6-dione, respectively were obtained.