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81.
Maëva-Charlotte Kervarec Prof. Dr. Erhard Kemnitz Priv.-Doz. Dr. Gudrun Scholz Dr. Svemir Rudić Prof. Dr. Thomas Braun Prof. Dr. Christian Jäger Dr. Adam A. L. Michalchuk Priv.-Doz. Dr. Franziska Emmerling 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(32):7314-7322
The very strong Lewis acid aluminium chlorofluoride (ACF) was loaded with anhydrous HF. The interaction between the surface of the catalyst and HF was investigated using a variety of characterization methods, which revealed the formation of polyfluorides. Moreover, the reactivity of the HF-loaded ACF towards the hydrofluorination of alkynes was studied. 相似文献
82.
Prof. Dr. Fa-Guang Zhang Xue-Qi Wang Yin Zhou Hong-Song Shi Zhe Feng Prof. Dr. Jun-An Ma Prof. Dr. Ilan Marek 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(67):15378-15396
Remote functionalization reactions have the power to transform a C−H (or C−C) bond at a distant position from a functional group. This Review summarizes recent advances and key breakthroughs in remote fluorination, trifluoromethylation, difluoromethylation, trifluoromethylthiolation, and fluoroalkenylation reactions. Several powerful strategies have emerged to control the reactivity and distal selectivity such as the undirected radical approach, the 1,5-hydrogen atom transfer, the metal migration, the use of distant directing groups, and the ring-opening reactions. These unconventional and predictable C−H (and C−C) functionalization transformations should allow for the preparation of a wide range of otherwise-difficult-to-access alkyl, aromatic, heteroaromatic, and structurally complex fluorides. 相似文献
83.
Tomasz Nienałtowski Paweł Szczepanik Paweł Małecki Dr. Dorota Czajkowska-Szczykowska Dr. Stefan Czarnocki Dr. Jolanta Pawłowska Dr. Anna Kajetanowicz Prof. Karol Grela 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(67):15708-15717
A large-scale synthesis of known Ru olefin metathesis catalyst VII featuring an unsymmetrical N-heterocyclic carbene (NHC) ligand with one 2,5-diisopropylphenyl (DIPP) and one thiophenylmethylene N-substituent is reported. The optimised procedure does not require column chromatography in any step and allows for preparation of up to 0.5 kg batches of the catalyst from simple precursors. The application profile of the obtained catalyst was studied in environmentally friendly dimethyl carbonate (DMC). Although VII exhibited low efficiency in cross-metathesis (CM) with electron-deficient partners, good to excellent results were noted for substrates featuring easy to isomerise C−C double bonds. This includes polyfunctional substrates of medicinal chemistry interest, such as analogues of psychoactive 5F-PB-22 and NM-2201 and two PDE5 inhibitors—Sildenafil and Vardenafil. Finally, a larger scale ring-closing metathesis (RCM) of a Vardenafil derivative was conducted in DMC, allowing for straightforward isolation of the expected product (23 g) in high yield and with low Ru contamination level (7.7 ppm). 相似文献
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88.
Xiao Ma Chongying Xu Zhibiao Mao Peiyu Ji Chenggang Jin Dongsheng Xu Yuqiang Ding 《应用有机金属化学》2020,34(2):e5349
A series of chemical vapor deposition (CVD) precursors have been synthesized by a single-step reaction of 1,1,3,3-tetramethylguanidine and a variety of silicon chlorides. The structures of the 1,1,3,3-tetramethylguanidinate-based compounds were verified by 1H NMR, 13C NMR, XPS, EI-MS, and elemental analysis. The thermal stability, transport behavior, and vapor pressures of these compounds were evaluated by simultaneous thermal analyses (STA). These compounds are highly stable and those in liquid form are very volatile. Silicon carbonitride (SiCN) thin films were prepared by using bis (tetramethylguanidine)-dimethyl-silane as the precursor in helicon wave plasma chemical vapor deposition (HWP-CVD). The properties of the films were investigated by SEM, AFM, and XPS. The results showed that the films have good uniformities, low friction coefficient, and high hardness, enabling the films for fabrication of semiconductor devices. 相似文献
89.
Zhongxian Song Yun Xing Tingji Zhang Jinggang Zhao Junkai Wang Yanli Mao Baolin Zhao Xuejun Zhang Min Zhao Ziang Ma 《应用有机金属化学》2020,34(3):e5446
A series of Ce-Fe-Ox catalysts prepared by the different calcination temperatures (marked as CF-X, where X represented calcination temperature) were used to the selectivity catalytic reduction of NOx by NH3. The results explained the relationship between calcination temperature and the sulfate species over Ce-Fe-Ox, and then investigated the surface acidity and catalytic performance. The large amounts of sulfate species were formed over CF-450 and CF-550 while it was decomposed with further the increasing of calcination temperature, which resulted in the loss of surface acidity, causing a decrease in the catalytic activity over Ce-Fe-Ox. Thereby, the CF-450 catalyst showed the best catalytic activity and over 90% NOx conversion was obtained at 244–450 °C. Besides, the favored pore structure, more Fe3+ active species, higher Ce3+ concentration and the abundance of chemical adsorbed oxygen species, as well as the surface acid sites, would together contribute to the excellent catalytic activity of CF-450 catalyst. 相似文献
90.
A series of new heteromultinuclear FeI/RuII clusters are described. The complexes (η6-arene)RuFe2S2(CO)6 (arene = p-cymene 1 , C6Me6 2 ) and Fe2[μ-S (Cp*Ru)(CO)2]2(CO)6 (Cp* = η5-C5Me5) ( 3 ) were prepared by the reduction reactions of (μ-S)2Fe2(CO)6 with 2 equiv of LiHBEt3, followed by treatment (μ-SLi)2Fe2(CO)6 with ruthenium-arene complexes Ru2(μ-Cl)2Cl2(η6-arene)2 or Cp*Ru (CO)2Cl in 22–33% yields. Further reactions of 1 and 2 with 1 equiv of triphenylphosphine in the presence of the decarbonylating agent Me3NO·2H2O, afforded the corresponding monophosphine-substituted FeI/RuII complexes (η6-arene)RuFe2S2(CO)5(Ph3P) (arene = p-cymene 4 , C6Me6 5 ) in 75% and 78% yields. While treatment of parent complex 1 or 2 with 1 equiv of diphosphine Ph2PCH2PPh2 (dppm) in xylene at reflux temperature resulted in the formation of the diphosphine-bridged RuFe2S2(CO)9 derivate RuFe2S2(CO)7(dppm) ( 6 ). The possible pathway for the formation was proposed. Two isomers of novel macrocyclic complexes involve the (η6-arene) Ru-bridged quadruple-butterfly Fe/S clusters [{μ-S (CH2)3S-μ}{(μ-CS2)Fe2(CO)6}2]2[(η6-arene)Ru]2 (arene = p-cymene 7a and 7b , C6Me6 8a and 8b ) were isolated by reactions of two μ-CS2-containing dianion [{μ-S (CH2)3S-μ}{(μ-S=CS)Fe2(CO)6}2]2− with [Ru2(μ-Cl)2Cl2(η6-arene)2], in which the propylene groups are attached to two S atoms by ee and ea types of bonds respectively. All the new complexes 1 – 8 have been characterized by elemental analysis, spectroscopy, and particularly for 1 – 6 , 7b and 8a by X-ray crystallography. In addition, the electrochemical properties of representative complexes 1 – 4 and 6 have been investigated. 相似文献