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125 results on '"Konev, Alexander S."'

13. 2020 Roadmap on gas-involved photo- and electro- catalysis

Author

Yang, Yulu, Tang, Yang, Jiang, Haomin, Chen, Yongmei, Wan, Pingyu, Fan, Maohong, Zhang, Rongrong, Ullah, Sana, Pan, Lun, Zou, Ji-Jun, Lao, Mengmeng, Sun, Wenping, Yang, Chao, Zheng, Gengfeng, Peng, Qiling, Wang, Ting, Luo, Yonglan, Sun, Xuping, Konev, Alexander S., Levin, Oleg V., Lianos, Panagiotis, Zhuofeng, Hu, Shen, Zhurui, Zhao, Qinglan, Wang, Ying, Todorova, Nadia, Trapalis, Christos, Sheridan, Matthew V., Wang, Haipeng, Zhang, Ling, Sun, Songmei, Wang, Wenzhong, and Ma, Jianmin

Published
2019
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22. Macromol. Chem. Phys. 24/2017

Author

Eliseeva, Svetlana N., primary, Alekseeva, Elena V., additional, Vereshchagin, Anatoliy A., additional, Volkov, Alexey I., additional, Vlasov, Petr S., additional, Konev, Alexander S., additional, and Levin, Oleg V., additional

Published
2017
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23. Stereselective cycloaddition of dibenzoxazepinium ylides to acetylenes and fullerene [C.sub.60]. Conformational behavior of 3-aryldibenzo[b,f]pyrrolo[1,2-d][1,4]oxazepine systems

Author

Khlebnikov, Alexander F., Novikov, Mikhail S., Petrovskii, Petr P., Konev, Alexander S., Yufit, Dmitrii S., Selivanov, Stanislav I., and Frauendorf, Holm

Subjects
Acetylene -- Chemical properties, Arylation -- Analysis, Ring formation (Chemistry) -- Analysis, Pyrrole -- Chemical properties, Biological sciences, Chemistry
Abstract

Cycloaddition of dibenzoxazepinium ylides to acetylene carboxylates has led to cis-3-aryl-3,13b-dihydrodibenzo[b,f]pyrrolo[1,2-d][1,4]oxazepinecarboxylates, which has dehydrogenated to the corresponding pyrrole derivatives. Stereoselective cycloaddition of dibenzoxazepinium ylides to fullerene [C.sub.60] has given rise to fulleropyrrolidines with cis-configuration and restricted Ph group rotation is seen in the phenyl derivative.

Published
2010

26. Concerted vs. Non-Concerted 1,3-Dipolar Cycloadditions of Azomethine Ylides to Electron-Deficient Dialkyl 2,3-Dicyanobut-2-enedioates

Author

Khlebnikov, Alexander F, Konev, Alexander S, Virtsev, Alexander A, Yufit, Dmitri S, Mlostoń, Grzegorz, Heimgartner, Heinz, University of Zurich, and Khlebnikov, Alexander F

Subjects
10120 Department of Chemistry, 1303 Biochemistry, 1503 Catalysis, 1604 Inorganic Chemistry, 3002 Drug Discovery, 540 Chemistry, 1606 Physical and Theoretical Chemistry, 1605 Organic Chemistry
Published
2014

29. Synthesis of fluorinated beta-lactams from fluorinated aziridines

Author

Konev, Alexander S., Novikov, Mikhail S., Khlebnikov, Alexander F., Abbaspour Tehrani, Kourosch, Department of Bio-engineering Sciences, and Organic Chemistry

Subjects
fluoroimine, aziridine, beta-lactam
Abstract

Fluorinated beta-lactams are useful building blocks for synthesis of fluorinated nitrogen-containing compounds. In addition, they can be of interest as potential pharmaceuticals and agrochemicals. Within the framework of our research of synthetic potential of fluoroaziridines (which can be easily prepared via reaction sequence involving generation of fluorocarbene by reduction of CHFBr2 with active lead in the presence of Bu4N+Br-, addition of carbene to azomethine and 1,3-cyclisation of resulting iminiofluoromethanide) we found conditions for isomerization of fluoroaziridines to alfa-fluoroimines. Isomerisation of 2,2-diphenylaziridines proceeds smoothly in dichloromethane at 40°C in the presence of SbF3 as a catalyst, while for the isomerisation of 2-alkyl-2-phenylaziridines more harsh conditions (dichloroethane, 70°C) are required. The reaction of the resulting imines with generated in situ ketene gives the side chain fluorinated beta-lactams in 22-62% yield. Unsymmetrically substituted ketenes (phenoxy- and acetoxyketene) stereoselectively give rise to cis-beta-lactams. The reaction can be performed as one-pot procedure without isolation of the imine.

Published
2007

30. Fluoroaziridines as convenient building blocks for synthesis of fluorinated imines, beta-lactams and propargyl amines

Author

Konev, Alexander S., Novikov, Mikhail S., Khlebnikov, Alexander F., Abbaspour Tehrani, Kourosch, Department of Bio-engineering Sciences, and Organic Chemistry

Subjects
beta-lactams, fluorinated compounds, boron, propargylic amines
Abstract

A simple and convenient route to fluorinated propargyl amines and beta-lactams was developed based on isomerisation of fluoroaziridines to alfa-fluoroimines as a key step.

Published
2007

31. A simple route to side-chain fluorinated beta-lactams from ring-fluorinated aziridines

Author

Konev, Alexander S., Novikov, Mikhail S., Khlebnikov, Alexander F., Abbaspour Tehrani, Kourosch, Department of Bio-engineering Sciences, and Organic Chemistry

Subjects
Staudinger, fluoroimine, beta-lactams, fluoroaziridines
Abstract

Beta-Lactams bearing a Ph2CF substituent at the C(4)-atom were synthesized from N-alkyl-2-fluoro-3,3-diphenylaziridines. The transformation was realized using SbF3-mediated isomerization of the monofluoroaziridines to fluorinated aldimines, followed by Staudinger reaction with ketenes. It was shown that this reaction sequence can be performed as a one-pot procedure.

Published
2006

36. Diastereospecific and Highly Site-Selective Functionalization of C70Fullerene by a Reaction with Diethyl N-Arylaziridine-2,3-dicarboxylates

Author

Lukyanov, Daniil A., Konev, Alexander S., Amsharov, Konstantin, Khlebnikov, Alexander F., and Hirsch, Andreas

Abstract

The diastereospecific and highly site-selective cycloaddition of N-arylazomethine ylides generated in situ from diethyl N-arylaziridine-2,3-dicarboxylates to C70fullerene is reported. The reaction provides C70fulleropyrrolidines in up to hundreds on a milligram scale as α- and β-adducts in a 4:1 ratio with a controlled stereochemical outcome: cis-aziridines give exclusively trans-adducts, and trans-aziridines give only cis-adducts. The 1H and 13C{1H} NMR spectra for different isomeric adducts were recorded and analyzed to identify some characteristic features, which permit an easy identification of isomeric adducts of this type.

Published
2018
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46. Synthesis of New Porphyrin-Fullerene Dyads Capable of Forming Charge-Separated States on a Microsecond Lifetime Scale.

Author

Konev, Alexander S., Khlebnikov, Alexander F., Prolubnikov, Pavel I., Mereshchenko, Andrey S., Povolotskiy, Alexey V., Levin, Oleg V., and Hirsch, Andreas

Subjects
*PORPHYRINS, *DYADS, *SMALL groups, *COUPLES, *DYADIC communication
Abstract

A series of covalently linked axially symmetric porphyrin-fullerene dyads with a rigid pyrrolo[3,4- c]pyrrolic linker enabling a fixed and orthogonal arrangement of the chromophores has been synthesized and studied by means of transient absorption spectroscopy and cyclic voltammetry. The lifetime of the charge-separated state has been found to depend on the substituents on the porphyrin core, reaching up to 4 μs for a species with meso-( p-MeOC6H4) substituents. The ground and excited electronic states of model compounds have been calculated at the DFT and TD-DFT B3LYP(6-31G(d)) levels of theory and analyzed with regard to the effect of the substituent on the stabilization of the charge-separated state in the porphyrin-fullerene ensemble with a view to explaining the observed dependence. [ABSTRACT FROM AUTHOR]

Published
2015
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49. Bisaziridine Tetracarboxylates as Building Blocks in the Stereoselective Synthesis of C60-Fullerene Diads and Dumbbell-like Bis-C60-fullerene Triads.

Author

Konev, Alexander S., Khlebnikov, Alexander F., and Frauendorf, Holm

Subjects
*FULLERENES, *PHENYLENEDIAMINES, *MOLECULES, *CARBON, *BIPHENYL compounds
Abstract

The synthesis of alkoxycarbonyl-substituted bisa-ziridines with the two aziridine units connected by conjugated p-phenylene, partly conjugated 1,1'-biphenyl-4,4'diyl, and non-conjugated 4,4'-metriylenediphenyI linkers was developed. The reaction of azomethine ylides derived from the bisaziridines with fullerene C60 was optimized and used for the stereoselective preparation of both the monoadducts (C60-linker-aziridine dicarboxylate), and the dumbbell bisadducts (C60-linker-C60). The reasons for the observed selectivity of the azomethine ylide formation and cydoaddition were theoretically studied at the DFT B3LYP/6-31G(d) level or at the ON1OM B3LYP/631G(d):B3LYP/STO-3G level for fullerene-containing molecules. [ABSTRACT FROM AUTHOR]

Published
2011
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