V.V. Sokolov, A.Yu. Ivanov, M.S. Avdontseva, A.A. Zolotarev
“Stereochemistry and NMR Spectra of Some Tricyclic Condensed Thiazolidine Derivatives with a Bridgehead Nitrogen Atom”
Chem. Hetercycl. Compd. 2014, 50, 550-556
DOI: 10.1007/s10593-014-1506-3
The configuration of a series of tricyclic condensed thiazolidines with a bridgehead nitrogen atom, for which erroneous data had been published, was determined by X-ray structural analysis and NMR spectroscopy.
J. Malinina, T.Q. Tran, A.V. Stepakov, V.V. Gurzhiy, G.L. Starova, R.R. Kostikov, A.P. Molchanov
“[3+2] Cycloaddition reactions of arylallenes with C-(N-arylcarbamoyl)- and C,C-bis(methoxycarbonyl)nitrones and subsequent rearrangements”
Tetrahedron Lett. 2014, 55, 3663-3666
DOI: 10.1016/j.tetlet.2014.04.107
The first example of 1,3-dipolar cycloaddition reactions of nitrones with arylallenes is described. C-Carbamoylnitrones react with the C1single bondC2 double bond of arylallenes affording the corresponding 4-methyleneisoxazolidines in good yields. N-Aryl-C,C-bis(methoxycarbonyl)nitrones usually gave rearranged products: mixtures of 4,5-dihydro-4-oxo-1H-benzo[b]azepine-2,2(3H)dicarboxylates and 4-oxo-1,5-diarylpyrrolidine-2,2-dicarboxylates.
P. R. Golubev, A. S. Pankova, M. A. Kuznetsov
“Transition-Metal-Free Approach to 4-Ethynylpyrimidines via Alkenynones”
Eur. J. Org. Chem. 2014, 3614-3621
DOI: 10.1002/ejoc.201402045
A practical approach to the synthesis of 4-ethynylpyrimidines by the condensation of arylamidines with 2-aryl-1-ethoxy-5-(trimethylsilyl)pent-1-en-4-yn-3-ones has been developed. As these latter ketones are easily accessible from bis(trimethylsilyl)acetylene and arylacetyl chlorides, the regioselective condensation reported herein provides a facile access to both TMS-protected and unprotected 4-ethynylpyrimidines in yields of up to 85%.
M. Popova, D. Michel
“Behavior of Sodium Lauroyl Sarcosinate in Solution and Binary Mixtures by Means NMR”
Applied Magnetic Resonance 2014, 45, 353-364
DOI 10.1007/s00723-014-0531-9
Measurements of the 1H and 13C chemical shifts as well as 1H spin–lattice relaxation times of sodium lauroyl sarcosinate (SLAS) in aqueous solutions and mixed binary systems with co-surfactants were carried out at various concentrations. It will be shown that changes in the chemical shifts for the N–CH2 groups in SLAS with increasing surfactant concentration can be used to estimate the ratio pcis /ptrans of cis– and trans-isomers. The relative fraction p trans of molecules in trans-configurations increases the most in a narrow concentration range 0.007–0.034 mol/l, i.e., at the transition from the monomeric state to the micelle. The ratio pcis /ptrans asymptotically decreases with increasing concentration, reaching a constant value at concentrations significantly above the critical micelle concentration. Thus, the ratio can be related to the process of micellization. If micellization takes place, the cis-isomer starts to transform into trans-isomer because the trans-isomer is more favorable in micelles. Because of the smaller cross section of the polar group region, the trans-conformation can be more easily incorporated into the micelle. In summary, the occurrence of micellar aggregates at low SLAS concentration in mixed systems can be clearly inferred from the nuclear magnetic resonance spectra.
Mikhail A. Kinzhalov, Konstantin V. Luzyanin, Irina A. Boyarskaya, Galina L. Starova, Vadim P. Boyarskiy
“Synthetic and structural investigation of [PdBr2(CNR)2] (R = Cy, Xyl)”
Journal of Molecular Structure 2014, 1068, 222–227
DOI: 10.1016/j.molstruc.2014.04.025
Reaction of cis-dichloro-bis-(cyclohexylisocyanide)palladium(II) ([PdCl2(CNCy)2], (1) or cis-dichloro-bis-(2,6-dimethylphenyl-isocyanide)palladium(II) ([PdCl2(CNXyl)2], (2) with excess of potassium bromide in acetone furnished complexes trans-dibromo-bis-(cyclohexylisocyanide)palladium(II) ([PdBr2(CNCy)2], (3) or trans-dibromo-bis-(2,6-dimethylphenylisocyanide)palladium(II) ([PdBr2(CNXyl)2], (4), respectively. Both compounds were characterized by elemental analyses (C, H, N), high resolution ESI+-MS, IR, 1H and 13C{1H} NMR spectroscopies, and their crystals were analyzed by a single-crystal and powder X-ray diffraction methods. To rationalise the dependence of the structure of 1–4 on type of halogen ligands, the Gibbs free energies of corresponding cis- and trans-isomers of 1–4 were estimated at the DFT B3LYP level of theory.
Ludmila L. Rodina, Jury J. Medvedev, Olesia S. Galkina and Valerij A. Nikolaev
“Thermolysis of 4-Diazotetrahydrofuran-3-ones: Total Change of Reaction Course Compared to Photolysis”
European Journal of Organic Chemistry 2014, 14, 2993–3000
DOI: 10.1002/ejoc.201400161
Thermolysis of 2,2,5,5-tetrasubstituted 4-diazodihydrofuran-3-ones in protic (BnOH) and aprotic (DMSO) media, in contrast to photolysis, gives rise to the formation of 2,2,4,5-substituted 3(2H)-furanones as a result of 1,2-alkyl (aryl) shift. The thermal stability of diazodihydrofuranones in these processes is determined by the nature of the substituents at the C-5 atom of the heterocyclic structure: alkyl and electron-donating groups in the para-position of the aryl substituent notably reduce the persistence of diazodihydrofuranones, whereas aryl groups and electron-withdrawing substituents increase their stability considerably. Thermolysis of substituted 4-diazodihydrofuran-3-ones in DMSO solution is a first-order reaction that furnishes higher yields of furanones than thermolysis in BnOH. The reaction can serve as a preparative method for the synthesis of tetrasubstituted-3(2H)-furanones.
E.Yu. Bulatov, T.G. Chulkova, I.A. Boyarskaya, V.V. Kondratiev, M. Haukka, V.Yu. Kukushkin
“Triple associates based on (oxime)Pt(II) species, 18-crown-6, and water: Synthesis, structural characterization, and DFT study”
J. Molec. Struct. 2014, 1068, 176-181
DOI: 10.1016/j.molstruc.2014.04.010
The associates 2(cis-[PtCl2(acetoxime)2])⋅18-crown-6⋅2H2O (1), 2(cis-[PtBr2(acetoxime)2])⋅18-crown-6⋅2H2O (2), and trans-[PtCl2(acetaldoxime)2]⋅(18-crown-6)⋅2H2O (3) were synthesized by co-crystallization of free corresponding platinum species and 18-crown-6 from wet solvents and characterized by 1H NMR and IR spectroscopies, high-resolution mass-spectrometry (ESI), TG/DTA, and X-ray crystallography. The (oxime)Pt(II) species are assembled with 18-crown-6 and water by hydrogen bonding between the hydroxylic hydrogen atoms of the oxime ligands and the oxygen atom of water and between the hydrogen atoms of water and the oxygen atoms of 18-crown-6. In 2(cis-[PtX2(acetoxime)2])⋅18-crown-6⋅2H2O (where X = Cl (1), Br (2)), the molecule of the crown ether is located between the two cis-[PtX2(acetoxime)2] species. The associate trans-[PtCl2(acetaldoxime)2]⋅(18-crown-6)⋅2H2O (3) crystallizes into a 1D array structure. Water molecules play the role of linkers between the (oxime)Pt(II) species and the crown ether molecules. The electronic structures and vibrational frequencies of the triple associates were studied by density functional theory (DFT/B3LYP).
I.O. Koshevoy, Y.-C. Chang, Y.-A. Chen, A.J. Karttunen, E.V. Grachova, S.P. Tunik, J.Janis, T.A. Pakkanen, P.-T. Chou
“Luminescent Gold(I) Alkynyl Clusters Stabilized by Flexible Diphosphine Ligands”
Organometallics, 2014, ASAP
DOI: 10.1021/om5002952
Treatment of the homoleptic decanuclear compounds (AuC2R)10 with the cationic gold diphosphine complexes [Au2(PR′2-X-PR′2)2]2+ results in high-yield formation of the new family of hexanuclear clusters [Au6(C2R)4(PR′2-X-PR′2)2]2+ (PR′2-X-PR′2 = PPh2-(CH2)n-PPh2, n = 2 (1, R = diphenylmethanolyl), n = 3 (3, R = diphenylmethanolyl; 4, R = 1-cyclohexanolyl; 5, R = 2-borneolyl), 4 (6, R = 1-cyclohexanolyl); PR′2-X-PR′2 = PCy2-(CH2)2-PCy2 (2, R = diphenylmethanolyl); PR′2-X-PR′2 = 1,2-(PPh2-O)-C6H4 (7, R = diphenylmethanolyl); PR′2-X-PR′2 = (R,R)-DIOP (8, R = diphenylmethanolyl)). In the case of PPh2-(CH2)4-PPh2 phosphine and −C2C(OH)Ph2 alkynyl ligands an octanuclear cluster of a different structural type, [Au8(C2C(OH)Ph2)6(PPh2-(CH2)4-PPh2)2]2+ (9), was obtained. Complexes 1–3, 7, and 9 were studied by X-ray crystallography. NMR and ESI-MS spectroscopic investigations showed that all but two (2 and 9) compounds are fluxional in solution and demonstrate dissociative chemical equilibria between major and a few minor forms. All of these complexes are intensely emissive in the solid state at room temperature and demonstrate very high quantum yields from 0.61 to 1.0 with weak influence of the alkynyl substituents R′ and the diphosphine backbones on luminescence energies. Two crystalline forms of the cluster 2 (P21/n and P21 space groups) exhibit unexpectedly contrasting yellow and sky blue emission, maximized at 572 and 482 nm, respectively. Electronic structure calculations with density functional methods demonstrate that the transitions responsible for the highly effective phosphorescence are dominated by contributions from the Au and π-alkynyl orbitals.
A.A. Melekhova, D.V. Krupenya, V.V. Gurzhiy, A.S. Melnikov, P.Yu. Serdobintsev, S.I. Selivanov, S.P. Tunik
“Synthesis, characterization, luminescence and non-linear optical properties of diimine platinum(II) complexes with arylacetylene ligands”
J. Organomet. Chem., 2014, accepted
DOI: 10.1016/j.jorganchem.2014.04.002
A series of platinum(II) complexes (diimine)Pt(C≣CR)2, where diimine is 2,2′-bipyridine (bpy) or 4,4′-bis(tert-butyl)-2,2′-bipyridine (dtbpy) and alkynyl ligand is biphenylacetylide or terphenylacetylide, were synthesized and their photophysical and non-linear optical properties were investigated. All compounds (1–3) were characterized using NMR spectroscopy, ESI mass-spectrometry and elemental analysis. X-Ray crystal structure of the complex containing 4,4′-bis(tert-butyl)-2,2′-bipyridine and terphenylacetylide ligands is reported. The electronic absorption and emission spectra of the complexes have been studied. Room temperature phosphorescence was observed for the complexes in solution with the luminescence quantum yield in the 7.5–11% range and excited state lifetimes in microsecond time domain. All complexes under study exhibit two-photon luminescence and their double quantum absorption cross-section was found to be in the 9–22 GM range.
Scientific supervisor – Valery Nikolaev.
We wish the applicant to defend successfully.
Defence will take place 26.06.2014 at 15:00 at Sredniy pr. 41/43, Department of Chemistry (BCA).