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1.
Fokin AA Kushko AO Kirij AV Yurchenko AG Schleyer PR 《The Journal of organic chemistry》2000,65(10):2984-2995
The reaction of a series of ketones with dimsylsodium in dimethyl sulfoxide resulting in the formation of gamma-unsaturated thiols was studied experimentally. [2,3]-Sigmatropic rearrangements of beta-unsaturated sulfinyl carbanions are involved at the key step of those transformations. DFT computations at the B3LYP/6-31+G level indicated that such rearrangements, as well as some typical [2, 3]-sigmatropic rearrangements, e.g., thermal rearrangements of allyl sulfoxides and Wittig rearrangements of sulfur ylides and lithiated allyloxy methyl anions, are concerted and moderately synchronous processes. Negative (diatropic) nucleus-independent chemical shifts (NICS) and high diamagnetic susceptibility exaltations indicate that the transition structures of these [2,3]-sigmatropic migrations are aromatic. 相似文献
2.
N. V. Pavlenko T. I. Oos N. V. Kirij Yu. L. Yagupolskii A. van Almsick L. Willms 《Chemistry of Heterocyclic Compounds》2011,47(4):435-440
Alkylation of 4(5)-substituted 1H-imidazoles using the corresponding reagents gave imidazole 1,4-isomers containing phosphoryl
and carboxyl groups together in the ring and in the alkyl fragment. The alkylation of pyrazoles containing a carboxyl group
at positions 3(5) and 4 of the ring using diethyl phosphonomethyltriflate has been studied. 相似文献
3.
Natalya V. Kirij Yurii L. Yagupolskii Wieland Tyrra Dr. Ingo Pantenburg Dieter Naumann Prof. Dr. 《无机化学与普通化学杂志》2007,633(7):943-945
represents the first structurally characterized example of a trifluoromethyl main group element compound with more than 8‐N (where N is the main group number) perfluoroalkyl groups and also the first fluoro(triorgano)tellurium derivative. Its polymeric nature is caused by asymmetric bridging fluorine atoms forming infinite chains. 相似文献
4.
S. V. Pasenok N. V. Kirij Yu. L. Yagupolskii D. Naumann W. Tyrra A. Fitzner 《无机化学与普通化学杂志》1999,625(5):834-838
The reactions of Zn(CF3)Br · 2 CH3CN, Cd(CF3)2 · 2 CH3CN or Bi(CF3)3/AlCl3 with tertiary amines lead to the formation of quaternary ammonium salts of the general formula [R3NCF2H]X. The reaction of 4‐N,N‐dimethylaminopyridine with Zn(CF3)Br · 2 CH3CN yields (N‐difluoromethyl)‐4‐N,N‐dimethylaminopyridinium bromide. Bi(CF3)3/AlCl3 reacts with 1,4‐diazabicyclo[2.2.2]octane to form a mixture of mono‐ and bis(difluoromethylammonium) salts. 相似文献
5.
Nicola Maggiarosa Wieland Tyrra Dieter Naumann Natalya V. Kirij Yurij L. Yagupolskii 《Angewandte Chemie (International ed. in English)》1999,38(15):2252-2253
The long-postulated reactive intermediates of polar fluoride-inititated trifluoromethylations with Me3SiCF3 (see scheme) were identified by NMR spectroscopy as [Me3Si(CF3)F]− and [Me3Si(CF3)2]−. 相似文献
6.
Dieter Naumann Natalya V. Kirij Nicola Maggiarosa Wieland Tyrra Yurii L. Yagupolskii Mathias S. Wickleder 《无机化学与普通化学杂志》2004,630(5):746-751
Syntheses and Characterizations of the First Tris and Tetrakis(trifluoromethyl) Palladates(II) and Platinates(II), [M(CF3)3(PPh3)]— and [M(CF3)4]2— (M = Pd, Pt) Tris(trifluoromethyl)(triphenylphosphino)palladate(II) and platinate(II), [M(CF3)3PPh3]—, and the tetrakis(trifluoromethyl)metallates, [M(CF3)4]2— (M = Pd, Pt), are prepared from the reactions of [MCl2(PPh3)2] and Me3SiCF3 / [Me4N]F or [I(CF3)2]— salts in good yields. [Me4N][M(CF3)3(PPh3)] crystallize isotypically in the orthorhombic space group Pnma (no. 62) with Z = 4. The NMR spectra of the new compounds are described. 相似文献
7.
R Nirmala V Sankaranarayanan K Sethupathi AV Morozkin T Geethakumary Y Hariharan 《Pramana》2002,58(5-6):1101-1104
New R
2Ti3Ge4 (R=Dy, Ho and Er) intermetallic compounds have been synthesized and characterized by X-ray diffraction and low temperature ac
magnetic susceptibility, electrical resistivity and thermoelectric power measurements were carried out. The compounds crystallize
in the parent, Sm5Ge4-type orthorhombic structure (space group Pnma) and lanthanide contraction is observed as one moves along the rare-earth series.
The changeover from paramagnetic to antiferromagnetic phase happens at low temperatures and the ordering temperature scales
with the de Gennes factor. The electrical resistivity is metallic with a negative curvature above 100 K. Thermopower displays
a weak maximum at temperatures less than 50 K signifying the possible phonon and magnon drag effects. 相似文献
8.
9.
Resonant ultrasound spectroscopy was used to measure the elastic constants of bcc Ta0.33V0.67 over the temperature range 3.5–300?K; the results were compared to earlier measurements on C15 TaV2. The temperature dependence of the polycrystalline shear modulus is completely different in the two phases; that of the bcc phase decreases with temperature whereas that of the C15 phases increases in an anomalous fashion. This difference is consistent with a model involving doubly-degenerate levels at the X point of the Brillouin zone in the C15 phase with the Fermi level lying near the doubly degenerate level. This model accounted for the unusual behaviour of the C15 phase. Debye temperatures were determined from the ultrasonic measurements: 295?K for the C15 phase and 315?K for the bcc phase. 相似文献
10.
Natalya V. Kirij Wieland Tyrra Dieter Naumann Ingo Pantenburg Yurii L. Yagupolskii 《无机化学与普通化学杂志》2006,632(2):284-288
Ligand exchange reactions of cis‐PtCl2(PPh3)2 and [NMe4]SCF3 in different ratios were studied. Depending on the stoichiometry reactions proceeded with formation of products expected for the chosen ratio, i. e. cis‐Pt(SCF3)Cl(PPh3)2, cis‐Pt(SCF3)2(PPh3)2, and [NMe4][Pt(SCF3)3(PPh3)]. Starting from cis‐PtCl2(MeCN)2 and [NMe4]SCF3 and adding PPh3 after substitution, product mixtures were dominated by the corresponding trans‐isomers. Results of the single crystal structure analyses of cis‐Pt(SCF3)2(PPh3)2 and trans‐Pt(SCF3)Cl(PPh3)2 are discussed. 相似文献