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1.
新颖的纳米镍催化芳基硼酸与芳基溴的偶联反应 总被引:7,自引:0,他引:7
纳米镍用于催化芳基硼酸与芳基溴的偶联反应,合成了一系列4,4′-双烷基环己基联苯类液晶,纳米镍在相转移剂十六烷基三甲基溴化铵的存在下回流反应15h,目的产物的收率为60%-65%。讨论了纳米镍催化偶联反应的可能活性位,镍催化剂经SEM-EDS表征平衡粒径为80nm,定量分析表明氧含量为33%;XRD测试结果表明纳米镍体相以单质态存在,但其特征谱线的d值普遍增大;由XPS分析得聘书纳米镍的结合能(2p3/2和2p1/2)为854.1eV和871.8eV,峰间距为17.7eV,表明纳米镍是以介于单质镍和氧化镍之间的价态存在。 相似文献
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The boron trifluoride induced Suzuki‐Miyaura cross‐coupling of aryltriazenes with arylboronic acids catalyzed by Pd(OAc)2 without added ligands has been achieved for the first time. The reactions performed at room temperature under an argon atmosphere give biaryls in good to excellent yields. It is noteworthy that the reactions were conducted under mild and ligand‐free conditions. 相似文献
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《中国化学》2018,36(2):143-146
Although bromodifluoromethane (BrCF2H) is a simple and readily available fluorine source, direct formation of difluoromethylated arenes with BrCF2H has not been reported. Herein, we describe an efficient method to access difluoromethylated arenes through a nickel‐catalyzed difluoromethylation of arylboronic acids with BrCF2H. The reaction exhibits high efficiency, good functional group tolerance and broad substrate scope, thus providing an efficient route for applications in drug discovery and development. Preliminary mechanistic studies reveal that a difluoromethyl radical is involved in the reaction. 相似文献
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JinXianWANG YuQuanZHANG 《中国化学快报》2004,15(6):641-642
A rapid and efficient method for synthesis of unsymmetrical ketones under microwave irradiation is reported. 相似文献
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Raymond Baker Malcom S. Nobbs Peter M. Winton 《Journal of organometallic chemistry》1977,137(3):C43-C47
Reactions of aldehyde and ketone methylhydrazones with butadiene in the presence of palladium complexes have been shown to yield N-octadienylated methylhydrazones. In contrast, in the presence of nickel complexes, a mixture of two isomeric azo-derivatives are formed from two moles of butadiene and one mole of methylhydrazone. The selectivity of these reactions is discussed in terms of the reactivity of the bis-π-allylmetal intermediates. 相似文献
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Chizhova N. V. Khelevina O. G. Berezin B. D. 《Russian Journal of General Chemistry》2003,73(10):1645-1647
Palladium(II) and nickel(II) complexes with octaphenyltetraazaporphyrin, octakis(4-bromophenyl)tetraazaporphyrin, and octakis(4-nitrophenyl)tetraazaporphyrin were obtained by reactions of octaphenyltetraazaporphyrin, Mg octaphenyltetraazaporphyrin, octakis(4-bromophenyl)tetraazaporphyrin, and octakis(4-nitrophenyl)tetraazaporphyrin with palladium(II) and nickel(II) chlorides in DMF. 相似文献
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Jonas Lindh Jonas Sävmarker Peter Nilsson Dr. Per J. R. Sjöberg Dr. Mats Larhed Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(18):4630-4636
One Heck of a reaction : Treatment of arylboronic acids or aryltrifluoroborates with vinyl acetate by using a palladium(II) catalyst gives the corresponding styrenes (see scheme). No palladium reoxidant is needed and the vinylation is performed under non‐inert conditions
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A new catalytic system based on palladium complex compounds for the unconventional allylation of norbornadiene with allylic esters of carboxylic acids is developed. The structure of reaction products is determined and the factors affecting their ratio are found. Comparative analysis of the palladium and nickel catalytic systems is performed. 相似文献
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We have demonstrated that 4,4′‐dimethyl 2,2′‐bipyridine as ligand for Pd(II) catalysts was very efficient for oxidative Heck‐type coupling reaction of arylboronic acids with olefins in DMA or CH3CN under atm air at 80 °C. The presence of chelated bipyridine ligand isindispensable to achieve high reaction yields and to suppress the formation of biphenyl as homocoupled byproduct. 相似文献
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Sylvia Kirchberg Roland Fröhlich Dr. Armido Studer Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(23):4235-4238
Indoles are not indolent : Various indoles react with arylboronic acids chemodivergently. C? H arylation of free indole and N‐methylindole gives the corresponding C(2)‐arylated indoles A whereas N‐acylated, N‐benzoylated, and N‐Boc‐protected indoles provide the corresponding arylcarboaminoxylated products B with excellent diastereoselectivity in good to excellent yields.
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Bruno Pribanic Monica Trincado Frederik Eiler Matthias Vogt Aleix Comas-Vives Hansjörg Grützmacher 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(36):15733-15739
The dehydrogenation of organosilanes (RxSiH4−x) under the formation of Si−Si bonds is an intensively investigated process leading to oligo- or polysilanes. The reverse reaction is little studied. To date, the hydrogenolysis of Si−Si bonds requires very harsh conditions and is very unselective, leading to multiple side products. Herein, we describe a new catalytic hydrogenation of oligo- and polysilanes that is highly selective and proceeds under mild conditions. New low-valent nickel hydride complexes are used as catalysts and secondary silanes, RR′SiH2, are obtained as products in high purity. 相似文献
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DFT studies on several dppf ‐ and dppc ‐derived bidentate phosphines ligated palladium complexes catalyzed Suzuki‐Miyaura coupling reactions were pursued. The catalytic reactions employing ligands, having two phosphine biting sites on different cyclpentadienyl or cyclobutadiene rings, such as 1,1'‐dmpf or 1,1' ‐dmpc, have been verified to be energetically more favorable than those on the same ring provided that tetra‐coordinated palladium conformations for all transition states and intermediates are maintained. Apart from the purpose of storage, the application of phosphinous acid (R2P(OH)) in Suzuki‐Miyaura reaction is inferior to tertiary phosphine (R3P). 相似文献
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Florian Livernaux Sidonie Laviéville Pascale Guiffrey Prof. Dr. Jean-Marc Campagne Dr. Eric Leclerc 《European journal of organic chemistry》2023,26(32):e202300467
The enantioselective addition of difluoroenoxysilanes to aromatic aldehydes, catalyzed by cationic palladium aqua complexes, has been described. The reaction is operationally simple, does not require anhydrous conditions and performs at room temperature. The palladium catalysts, previously discovered and reported by Sodeoka, are easily prepared in two steps from PdCl2(MeCN)2. The aldol compounds were obtained in good yields and with enantiomeric ratios up to 93 : 7, the reaction being more efficient using electron-rich aldehydes. 相似文献
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DFT studies on several dppf ‐ and dppc ‐derived bidentate phosphines ligated palladium complexes catalyzed Suzuki‐Miyaura coupling reactions were pursued. The catalytic reactions employing ligands, having two phosphine biting sites on different cyclpentadienyl or cyclobutadiene rings, such as 1,1′‐dmpf or 1,1′‐dmpc , have been verified to be energetically more favorable than those on the same ring provided that tetra‐coordinated palladium conformations for all transition states and intermediates are maintained. Apart from the purpose of storage, the application of phosphinous acid (R2P(OH)) in Suzuki‐Miyaura reaction is inferior to tertiary phosphine (R3P). 相似文献
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Zhe Wang Fei Xue Tamio Hayashi 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(32):11170-11173
The one‐step synthesis of arylacetaldehydes by carbon–carbon bond formation between formylmethyl and aryl groups has been realized by the reaction of vinylene carbonate with arylboronic acids in the presence of an iridium/bisphosphine catalyst and a catalytic amount of tetrahydroxydiboron. 相似文献
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The direct arylation of substituted pyridines with several arylboronic acids has been developed. This transformation could proceed readily at ambient temperature using inexpensive reagents: iron(II) oxalate as a catalyst, potassium persulfate as a co‐oxidant, which can afford the arylated products in mild to good yields. The mechanism is presumed to proceed through a nucleophilic radical addition to the pyridines with in situ reoxidation. 相似文献