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Pihlaja K Klika KD Sinkkonen J Ovcharenko VV Maloshitskaya O Sillanpää R Czombos J 《The Journal of organic chemistry》2002,67(6):1910-1917
Both cis- and trans-fused 4a,5,6,7,8,8a-hexahydro-2H,4H-1,3-benzodithiine together with their 2-methyl and 2,2-dimethyl derivatives were prepared as racemates from the appropriate dithiols obtained via multistep syntheses. The products were characterized by (1)H and (13)C NMR, mass spectrometry, and for two of the cis-fused compounds by X-ray diffraction. (1)H,(1)H vicinal coupling constants indicated that all compounds attain chair-chair conformations as their predominant conformations. All three trans-fused isomers exist in totally biased chair-chair conformations and are essentially conformationally locked, whereas the cis-fused compounds are conformationally mobile and can potentially attain either the S-in or the S-out conformation. The interconversion of the conformers is fast on the NMR time-scale at ambient temperatures, but at 213 K 4ar,5,6,7,8,8ac-hexahydro-1,3-benzodithiine freezes out into a 83:17 mixture of the S-in and S-out forms, respectively. Both 2c-methyl-4ar,5,6,7,8,8ac-hexahydro-1,3-dithiine and the dimethyl derivative adopt almost exclusively the S-in conformer at ambient temperature whereas 2t-methyl-4ar,5,6,7,8,8ac-hexahydro-1,3-dithiine is a 5:1 mixture of the S-out and S-in conformers. 相似文献
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S. P. Panchenko A. C. Abel A. D. Averin O. A. Maloshitskaya E. N. Savelyev B. S. Orlinson I. A. Novakov I. P. Beletskaya 《Russian Chemical Bulletin》2016,65(6):1550-1555
A copper(I) complex-catalyzed N,N’-diarylation of diamines based on 1,3-disubstituted adamantane, using aryl iodides bearing electron-donating and electron-withdrawing substituents, was studied. In the case of 2,2’-(adamantane-1,3-diyl)ethanediamine, the optimal catalyst system is CuI—2-(isobutyryl)cyclohexanone—Cs2CO3—DMF. The highest yield of diarylation product was reached in the case of 4-methoxyiodobenzene (79%). In the case of more spatially hindered adamantane-1,3-diyldimethanamine, 1,1’-binaphthalene-2,2’-diol (BINOL) should be used, with the highest yield of the target product (84%) being reached in the reaction with iodobenzene. 相似文献
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Alessenko A. V. Shupik M. A. Gutner U. A. Zateyshchikov D. A. Minushkina L. O. Rogozhina A. A. Lebedev A. T. Maloshitskaya O. A. Sokolov S. A. Kurochkin I. N. 《Journal of Analytical Chemistry》2022,77(4):439-449
Journal of Analytical Chemistry - Cardiolipidology – a new direction in cardiology – is developing intensively owing to the method of mass spectrometry. This method has acquired... 相似文献
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S. P. Panchenko A. S. Abel A. D. Averin O. A. Maloshitskaya E. N. Savelyev B. S. Orlinson I. A. Novakov I. P. Beletskaya 《Russian Journal of Organic Chemistry》2017,53(10):1497-1504
Arylation of adamantane-containing amines with iodobenzene in the presence of copper(I) and copper(II) compounds and various N,N-, N,O- and O,O-bidentate ligands was studied. The best results were obtained using the catalytic system CuI–rac-BINOL [1,1′-bi(naphthalen-2-ol)] (10/20 mol %). Reactions with iodobenzene derivatives containing electron-donor and electron-withdrawing substituents in the para position to the iodine atom were carried out under the optimal conditions. 相似文献
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Olga A. Maloshitskaya Valery V. Alekseyev Kirill N. Zelenin Kalevi Pihlaja 《Tetrahedron》2006,62(40):9456-9466
The reaction products of 1,3-butanediamine and 2-methyl-2,4-pentanediamine with β-keto aldehydes were shown by 1H and 13C NMR spectroscopy to exist as tautomeric mixtures in solutions, comprising one cyclic and two open-chain forms due to the non-equivalence of the amino groups. The chain products exist as Z- and E-isomers. After equilibration, the products from 1,3-butanediamine contain relatively less of the cyclic form than those from 2-methyl-2,4-pentanediamine. The products of 2-methyl-2,4-pentanediamine with p-substituted aroylacetaldehydes, exhibit a linear correlation between log K of the ring-chain equilibria and Hammett's σ values of the aromatic ring substituents. α-Substitution of β-keto aldehydes notably increased the relative amounts of the chain E-isomers in their condensation products and also resulted in the formation of two diastereomers for each of the cyclic products. No ring-chain equilibria were observed in the products of 1,3-butanediamine and 2-methyl-2,4-pentanediamine with β-diketones, β-keto esters, or β-keto amides. 相似文献