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排序方式: 共有245条查询结果,搜索用时 15 毫秒
101.
Richard Neidlein Dao Droste-Tran-Viet Alfred Gieren Michail Kokkinidis Rudolf Wilckens Hans-Peter Geserich Wofgang Ruppel 《Helvetica chimica acta》1984,67(2):574-582
Syntheses, Chemical and Electrical Properties of Tetrathiafulvalene with a 1,6-Methano[10]annulene Moiety and of Chalcogendiimide-Derivatives The synthesis of the tetrathiafulvalene 6 has been described: the reaction of 1 with the benzenedithoil 2 yielded the bis-dithioacetal 3 of 1,6-methano[10]annulene-dicarbaldehyde 1 . The oxidation of 3 in the presence of HBF4 in Et2O yielded the salt 4 , elimination of a hydride anion with triphenylmethylium tetrafluoroborate the salt 5 , and elimination of a proton in 5 with Et3N the tetrathiafulvalene 6 with a 1,6-methano[10]annulene moiety. The spectroscopic and electrochemical properties of 6 are described, and also the syntheses and properties of charge-trasnfer complexes 7 and 8 , including the properties of electric conductivity of 7 and 8 . the syntheses of 9-13 are reported and also their spectroscopic properties. 相似文献
102.
Novel AC and DC Non-Thermal Plasma Sources for Cold Surface Treatment of Polymer Films and Fabrics at Atmospheric Pressure 总被引:7,自引:0,他引:7
Akishev Yuri Grushin Michail Napartovich Anatoly Trushkin Nikolay 《Plasmas and Polymers》2002,7(3):261-289
Novel types of non-thermal plasma sources at atmospheric pressure based on multi-pin DC (direct current) diffusive glow discharge and AC (alternative current) streamer barrier corona have been elaborated and tested successfully for cold surface treatment of polymer films [polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET),] and polyester fabric. Results on physical properties ofdischarges mentioned and output energy characteristics of new plasma sources as well as data on after-treatment changes in wettability of films and fabrics are presented. The main goal of this study was to find out the experimental conditions for gas discharge and surface processing to achieve a remarkable wettability change for a short treatment time. 相似文献
103.
Catalysis of Cascade and Multicomponent Reactions of Carbonyl Compounds and CH Acids by Electricity 下载免费PDF全文
Michail N. Elinson Anatoly N. Vereshchagin Fedor V. Ryzhkov 《Chemical record (New York, N.Y.)》2016,16(4):1950-1964
This review is concerned with modern trends in the use of electrochemically induced chain reactions in cascade and multicomponent electroorganic synthesis. The review summarizes the data on the use of electrochemically induced chain reactions in cascade and multicomponent organic synthesis, which were published mainly in the last decade. 相似文献
104.
Julia N. Blyzniuk Michail A. Semenov Anna Victorovna Shestopalova 《Structural chemistry》2016,27(1):77-89
We report results of the Monte Carlo simulations of systems containing heterodimers of biological active ligands and water molecules. The study was designed to identify the possible formation of intermolecular hydrogen bonds in such systems in order to investigate the molecular mechanisms of hetero-association of aromatic ligands in aqueous solution. The geometry optimization and the calculation of the atomic charges of free ligands were carried out at DFT/B3LYP level of theory. Monte Carlo simulations with Metropolis algorithm were used to determine the low energy conformations of heterodimers in water clusters. The analysis of the Monte Carlo simulation results allows us to describe in detail the hydration properties of all investigated heterodimers and to determine the intermolecular hydrogen bonds between the functional donor–acceptor groups for some of hetero-associates under investigation. In the case of heterodimers without intermolecular hydrogen bonds, the additional stabilization of these hetero-complexes can be explained by the formation the water bridges between donor and acceptor groups of the ligands. 相似文献
105.
Total Synthesis and Biological Evaluation of Rakicidin A and Discovery of a Simplified Bioactive Analogue 下载免费PDF全文
Dr. Michail Tsakos Dr. Lise L. Clement Dr. Eva S. Schaffert Frank N. Olsen Sebastiano Rupiani Rasmus Djurhuus Wanwan Yu Kristian M. Jacobsen Nikolaj L. Villadsen Prof. Dr. Thomas B. Poulsen 《Angewandte Chemie (International ed. in English)》2016,55(3):1030-1035
We report a concise asymmetric synthesis of rakicidin A, a macrocyclic depsipeptide that selectively inhibits the growth of hypoxic cancer cells and stem‐like leukemia cells. Key transformations include a diastereoselective organocatalytic cross‐aldol reaction to build the polyketide portion of the molecule, a highly hindered ester fragment coupling reaction, an efficient Helquist‐type Horner—Wadsworth—Emmons (HWE) macrocyclization, and a new DSC‐mediated elimination reaction to construct the sensitive APD portion of rakicidin A. We further report the preparation of a simplified structural analogue (WY1) with dramatically enhanced hypoxia‐selective activity. 相似文献
106.
Michail N. Elinson Sergey K. Feducovich Nikita O. Stepanov Anatolii N. Vereshchagin Gennady I. Nikishin 《Tetrahedron》2008,64(4):708-713
The new reaction was found: the direct formation of cyclopropanes from activated olefins and C-H acids. The action of free halogen or active halogen containing compounds on the equal amounts of benzylidenemalononitriles and malononitrile in basic alcohol solutions results in the formation of 3-aryl-1,1,2,2-tetracyanocyclopropanes in 65-95% yields. Thus, the new simple and efficient way to 3-aryl substituted tetracyanocyclopropanes was found directly from such simple and reasonable starting compounds as benzylidenemalononitriles and malononitrile. 相似文献
107.
108.
Fast Efficient and General PASE Approach to Medicinally Relevant 4H,5H‐Pyrano‐[4,3‐b]pyran‐5‐one and 4,6‐Dihydro‐5H‐pyrano‐[3,2‐c]pyridine‐5‐one Scaffolds 下载免费PDF全文
Michail N. Elinson Fedor V. Ryzhkov Ruslan F. Nasybullin Anatoly N. Vereshchagin Mikhail P. Egorov 《Helvetica chimica acta》2016,99(9):724-731
The general ‘on‐solvent’ PASE approach was found to be medicinally relevant for 4H,5H‐pyrano[4,3‐b]pyran‐5‐one and 4,6‐dihydro‐5H‐pyrano[3,2‐c]pyridine‐5‐one scaffolds. Ammonium acetate‐catalyzed multicomponent reaction of aldehydes and two different C–H acids in the presence of small amounts of EtOH results in fast (3 – 15 min) and efficient formation of scaffolds, promising for many diverse oriented medical applications. 相似文献
109.
110.
Shorouk Elnagdy Michail Raptopoulos Ioannis Kormas Alessandro Pedercini Larry F. Wolff 《Molecules (Basel, Switzerland)》2021,26(18)
Despite many discoveries over the past 20 years regarding the etiopathogenesis of periodontal and peri-implant diseases, as well as significant advances in our understanding of microbial biofilms, the incidence of these pathologies continues to rise. For this reason, it was clear that other strategies were needed to eliminate biofilms. In this review, the literature database was searched for studies on locally delivered synthetic agents that exhibit anti-biofilm properties and their potential use in the treatment of two important oral diseases: periodontitis and peri-implantitis. 相似文献