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301.
A general procedure has been developed for the synthesis of hitherto unknown substituted allyl bromides. The procedure includes preparation of the corresponding α,β-unsaturated carboxylic acid esters from accessible ketones according to the Horner-Emmons reaction, reduction of these esters with diisobutylaluminum hydride to allylic alcohols, and substitution of the hydroxy group by bromine by the action of PBr3. The E,Z isomer ratio of the synthesized unsaturated compounds ranges from 3: 1 to 4: 1. 相似文献
302.
The reaction of tert-butyl 4-oxopiperidine-1-carboxylate dimethylhydrazone with BuLi and further with iodides of protected alcohols ICH2(CH2) n OSiMe2(t-Bu) (n = 1–4) led to the formation of the corresponding tert-butyl 3-{[tert-butyl(dimethyl)silyl]alkyl}-4-oxopiperidine-1-carboxylates that under the treatment with triethylsilane in the presence of anhydrous BiBr3 underwent cyclization with a high stereoselectivity into cis-isomers of N-Boc piperidine derivatives [3,2-c]-fused with oxygen heterocycles. The latter at the treatment with anhydrous HCl eliminate the Boc group affording hydrochlorides of stereochemically homogeneous N-unsubstituted fused bicyclic systems. 相似文献
303.
Treatment of the title compound with trifluoroacetic acid induced intramolecular Schmidt reaction with formation of a saturated fused heterocyclic system, tert-butyl 5-oxo-2,3,4,5,7,8,9,9a-octahydro-1H-pyrrolo[1,2-a][1,4]-diazepine-2-carboxylate. The latter was reduced with lithium tetrahydridoaluminate, and subsequent treatment with hydrogen chloride in dioxane gave 2,3,4,5,7,8,9,9a-octahydro-1H-pyrrolo[1,2-a][1,4]-diazepine dihydrochloride which is a promising intermediate product for the synthesis of N-substituted diazepines with a fused pyrrole ring. 相似文献
304.
Aleksandr Aglikov Olga Volkova Anna Bondar Dr. Ivan Moskalenko Prof. Dr. Alexander Novikov Prof. Dr. Ekaterina V. Skorb Prof. Dr. Evgeny Smirnov 《Chemphyschem》2023,24(17):e202300187
The emerging novel class of two-dimensional materials – MХenes – have attracted significant research attention. However, there are only few reports on using the most prominent member of the MXene family, Ti3C2Tx, as an active material for memristive devices within a polyelectrolyte matrix and its deposition on inert electrodes like ITO and Pt. In this study, we systematically investigate Ti3C2Tx MXenes synthesized with two classical delamination agents, such as lithium chloride and tetramethylammonium hydroxide, to identify the most suitable candidate for memristive device applications. The characteristics of memristors based on the hybrid structures consisting of MXene−polyelectrolyte multilayers, specifically polyethyleneimine (PEI) and poly(sodium 4-styrenesulfonate) (PSS) are explored. The PEI(MXene)/PSS memristor exhibits a voltage threshold (VSET/RESET) range of 1.5–2.0 V, enabling the transition from a high-resistive state (HRS) to a low-resistive state (LRS), along with a significant current switching ratio of approximately two orders of magnitude. The observed VSET/RESET difference of approximately 4 V is further supported by density functional theory (DFT) calculated redox potential. These findings underscore the potential of polyelectrolyte-based memristors, such as the in PEI−Ti3C2Tx−PSS system, in facilitating the development of highly functional, self-assembled memristive devices with diverse applications. 相似文献
305.
V. I. Maleev Z. T. Gugkaeva A. T. Tsaloev M. A. Moskalenko V. N. Khrustalev 《Russian Chemical Bulletin》2012,61(1):51-58
The amide and sulfamide derivatives of (1R,2R)-N,N-diethylcyclohexane-1,2-diamine can serve as organocatalysts for addition of Me3SiCN and Et2Zn to aldehydes. 相似文献
306.
V. I. Maleev Z. T. Gugkaeva M. A. Moskalenko A. T. Tsaloev K. A. Lyssenko 《Russian Chemical Bulletin》2009,58(9):1903-1907
(2S)-N-
2-[(R)-Hydroxy(phenyl)methyl]phenylpyrrolidine-2-carboxamide, (2 S)-N-{2-[(S)-hydroxy(phenyl)methyl]phenyl}pyrrolidine-2-carboxamide, and (S)-N-{2-[hydroxy-(diphenyl)methyl]phenyl}pyrrolidine-2-carboxamide were obtained and tested as catalysts for an asymmetric aldol
reaction of 4-nitrobenzaldehyde with acetone. 相似文献
307.
The Goos-H?nchen effect and Fano resonance are studied in photonic crystals that are considered Fourier counterparts in wave-vector-coordinate space. The Goos-H?nchen effect, which is enhanced by the excitation of Bloch surface electromagnetic waves, is visualized using far-field microscopy and measured at the surface of photonic crystals by angular spectroscopy. The maximal Goos-H?nchen shift is observed to be 66 μm. 相似文献
308.
A. A. Koronovskii O. I. Moskalenko S. A. Shurygina A. E. Hramov 《Bulletin of the Russian Academy of Sciences: Physics》2012,76(12):1339-1342
The existing concept of the weak and strong synchronization in discrete maps is verified. The state vectors of interacting chaotic systems are shown to be related to each other by the functional relation only in the strong synchronization regime; in the weak regime, the prehistory must be taken into account. An approach to determining the threshold of generalized synchronization in such systems is proposed. 相似文献
309.
M. O. Zhuravlev A. A. Koronovskii O. I. Moskalenko A. E. Hramov 《Bulletin of the Russian Academy of Sciences: Physics》2012,76(12):1346-1348
A new level of organization of the temporal behavior of two coupled complex systems is revealed. We report for the first time the coexistence of two types of intermittent behavior that occurs simultaneously near the boundary of the synchronization regime of coupled chaotic oscillators. This intricate phenomenon was observed both experimentally in a physiological experiment and numerically. The laws for both the distribution and the mean length of the laminar phases versus the control parameter values are analytically deduced. Very good agreement between the theoretical results and the numerically calculated data is shown. 相似文献
310.
M. M. Mezdrogina M. V. Eremenko S. M. Golubenko E. S. Moskalenko 《Physics of the Solid State》2012,54(1):194-201
The influence of nanoparticles and thin layers of Au, Eu phthalocyanine, and Er nanoparticles on the formation of luminescence
spectra of InGaN/GaN quantum-well structures has been investigated. It has been shown that the influence of localized plasmons
on the generation of charge carriers is determined by the size of Au nanoparticles under the assumption that the interaction
of plasmons with surface states of the structures plays a dominant role. The influence of Au nanoparticles on the formation
of luminescence spectra of multiple quantum-well structures based on InGaN/GaN, unlike the case of Au layers, is determined
by the indium concentration. The influence of Eu phthalocyanine films, which are deposited onto the surface of the studied
structures, on their photoluminescence spectra is similar to the influence of doping of these structures with europium. 相似文献