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1.
V. N. Tsarev S. E. Lyubimov S. V. Zheglov A. A. Shiryaev V. A. Davankov K. N. Gavrilov 《Russian Chemical Bulletin》2004,53(9):2025-2028
A chiral P,N-bidentate aryl phosphite ligand containing peripheral (R)-(+)-camphor-derived ketimine and its rhodium(I) and palladium(II) chelate complexes were synthesized for the first time. These compounds were found to be suitable for asymmetric allylic substitution. The Pd-catalyzed sulfonylation of 1,3-diphenylallyl acetate with sodium p-toluenesulfinate gave the product in 73% ee; in the alkylation of the same substrate with dimethyl malonate, the ee was 94%. These ee values are higher than the enantioselectivity achieved with the known phosphine analogs.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1942–1945, September, 2004. 相似文献
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Konstantin N. Gavrilov Alexei A. Shiryaev Ilya V. Chuchelkin Sergey V. Zheglov Eugenie A. Rastorguev Vadim A. Davankov Armin Börner 《Tetrahedron: Asymmetry》2012,23(14):1052-1057
New P,P-bidentate diastereomeric diphosphoramidite chiral ligands with mixed stereogenic elements and a C1 backbone symmetry have been prepared from (Sa)- and (Ra)-1,1′-binaphthyl-2,2′-diol (BINOL) and (S)-N-benzyl-1-(pyrrolidin-2-yl)methanamine and are fully characterized. The use of these ligands provides up to 84% ee in the Pd-catalyzed asymmetric allylic substitution of (E)-1,3-diphenylallyl acetate and up to 95% ee in the Rh-catalyzed asymmetric hydrogenation of α-dehydrocarboxylic acid esters. The results indicate that the catalytic performance is highly affected by the axial chirality of the binaphthyl moieties of the ligand and the nature of the solvent. 相似文献
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K. N. Gavrilov I. V. Chuchelkin S. V. Zheglov A. A. Shiryaev O. V. Potapova I. M. Novikov E. A. Rastorguev P. V. Petrovskii V. A. Davankov 《Russian Chemical Bulletin》2012,61(10):1925-1932
The synthesis of new P*-mono- and P*,N-bidentate diamidophosphites, containing 1,3,2-diazaphospholidine rings formed starting from (2S,3S)-N 2,3-dimethyl-N 1-phenylpentane-1,2-diamine, is described. Comparison of their efficiency in the Pd-catalyzed enantioselective allylation with (E)-1,3-diphenylallyl acetate showed that up to 97% ee was reached in the reaction involving dimethyl malonate as a C-nucleophile. The Pd-catalyzed desymmetrization of N,N′-ditosyl-meso-cyclopent-4-ene-1,3-diol biscarbamate gave up to 61% ee. 相似文献
4.
K. N. Gavrilov E. A. Rastorguev S. V. Zheglov N. N. Groshkin V. E. Boyko A. S. Safronov P. V. Petrovskii V. A. Davankov 《Russian Chemical Bulletin》2010,59(6):1242-1247
P,P-Bidentate diamidophosphite ligands containing the (3R,4R)-3,4-dioxy-1-(1-naphthyl)pyrrolidine-2,5-dione framework and 1,3,2-diazaphospholidine rings with the stereogenic P atoms
were obtained. The use of these ligands provides up to 85% ee in Pd-catalyzed asymmetric amination of (E)-1,3-diphenylallyl acetate and up to 95% ee in its asymmetric alkylation with dimethyl malonate. 相似文献
5.
Siberian Mathematical Journal - We construct Lax pairs for linear Hamiltonian systems of differential equations. In particular, the Gröbner bases are used for computations. It is proved that... 相似文献
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The influence of local distortions on the structure and properties of copper and silver impurity Jahn-Teller complexes in mixed crystals, namely, CaxSr1?x F2: Me 2+ and Sr1?x BaxF2: Me 2+ (0≤x≤1, Me 2+=Cu2+ or Ag2+), is investigated using electron paramagnetic resonance (EPR) spectroscopy at frequencies of 9.3 and 37 GHz in the temperature range 4.2–250 K. Local distortions of the tensile and compressive types are induced by Ca2+, Sr2+, and Ba2+ impurity ions incorporated into the first or second coordination sphere of the cationic environment of the Me 2+ impurity ion during crystal growth. 相似文献
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Eduard B. Benetsky Sergey V. Zheglov Fliur Z. Macaev Vadim A. Davankov 《Tetrahedron letters》2007,48(47):8326-8330
A new family of readily available modular phosphite, phosphoramidite and diamidophosphite ligands with P∗-stereocentres have been prepared from inexpensive optically active precursors. Using these novel ligands, up to 91% ee was achieved in Pd-catalysed asymmetric allylic amination. The catalytic performance is affected greatly by the structure of the phosphocentre of the ligand. 相似文献
10.
Doklady Mathematics - In the paper, Lax pairs for linear Hamiltonian systems of differential equations are found. Besides, first integrals of the system which are obtained from the Lax pairs are... 相似文献