共查询到20条相似文献,搜索用时 15 毫秒
1.
Ke Ding 《Tetrahedron letters》2005,46(21):3707-3709
Analogues of 3-aryl-8-isobutyl-5,6,7-trihydroxy-2-methyl-4H-chromen-4-one were synthesized with high yields via the Suzuki coupling reaction of 3-iodo-8-isobutyl-5,6,7-trimethoxy-2-methyl-4H-chromen-4-one with different aryl boronic acids. 相似文献
2.
Monodispersed palladium phosphide(Pd_3P)(5.2 ± 0.5 nm) was firstly applied to photocatalytic Suzuki coupling reaction under visible light irradiation with CdS nanoflake as a photo sensitizer.This heterogeneous system exhibited high yields to corresponding products and excellent stability in alcohol solvent at room temperature. 相似文献
3.
Meenakshi Choudhary Rafique Ul Islam Michael J Witcomb Motlatsi Phali Kaushik Mallick 《应用有机金属化学》2013,27(9):523-528
We report here a method for the preparation of polymer hollow spheres in which 3‐aminoquinoline (3‐AQ) and palladium acetate were used as precursors. During the reaction 3‐AQ was oxidized and formed poly(3‐AQ). IR and Raman spectra provided information on the chemical structure of the polymer. The oxidation state of palladium was confirmed by X‐ray photoelectron spectroscopic analysis. Transmission and scanning electron microscopy were used to determine the size and morphology of the polymer. The palladium–poly(3‐AQ) supramolecular system was used as an effective catalyst for the Suzuki coupling reaction of aryl halides in the absence of a phosphine ligand. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
4.
A new palladium incorporated carbonaceous catalyst Pd@CCSO3HNH2 was synthesized by introducing palladium on glucose derived carbocatalyst. The catalyst was well characterized and was used for the Suzuki coupling of phenyl boronic acid with different aryl halides under aqueous conditions. This green methodology represents a ligand free, cost-effective and operationally convenient method for the synthesis of a variety of biaryl’s under the conditions that are tolerant for a broad range of functional groups with good to excellent yields. Moreover, the catalyst could be easily recycled and reused at least five times without any significant loss of its catalytic activity. 相似文献
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Sanjay Jadhav Gajanan Rashinkar Rajashri Salunkhe Arjun Kumbhar 《Tetrahedron letters》2017,58(33):3201-3204
A simple, efficient and metal-free route for the synthesis of dissymmetric ketones through Suzuki type cross-coupling reaction has been established. This strategy signifies an attractive, cost-effective and operationally convenient tool for the synthesis of a wide range of dissymmetric ketones. Although conventional routes for the synthesis of ketones have been widely used, the potential challenge with these methods is functional group tolerance. The reported metal-free method represents a reaction with moderate functional group tolerance. The procedure is operationally convenient and shows broad substrate scope with good to excellent product yields. 相似文献
8.
Three series of compounds characterized by biphenylic structure were synthesized in order to develop new scaffolds able to induce β-sheet folding in the peptides. Microwave flash heating was used in order to shorten reaction times and to enhance the obtained yields. Simulated annealing molecular dynamics simulations demonstrated that some of the compounds were capable of adopting a 15-membered intramolecularly hydrogen-bonded conformation, which supports an antiparallel β-sheet structure. 相似文献
9.
采用3-巯丙基三甲氧基硅烷为内表面修饰剂,三甲氧基苯基硅烷为外表面修饰剂,合成了内外表面被修饰的介孔分子筛SBA-15,并制备了负载钯催化剂.应用X射线粉末衍射仪(XRD),傅立叶红外光谱仪(FT-IR),紫外可见光谱仪,扫描(SEM)、透射(TEM)电子显微镜等仪器对材料结构进行了表征.考察了负载钯催化剂在超临界二氧化碳介质中催化Suzuki偶联反应的活性,结果表明:制得的负载钯催化剂稳定、活性高;以四丁基乙酸胺为碱,对溴硝基苯与苯硼酸在90℃下反应48 h,得到71%收率的对硝基联苯. 相似文献
10.
Wei Wang Rongliang Wang Fan Wu Boshun Wan 《Reaction Kinetics and Catalysis Letters》2005,85(2):277-282
Summary A Ni-promoted ligand free palladium catalyst system for Suzuki coupling of aryl bromides has been developed in high efficiency under mild reaction conditions. It was obtained in situ by introducing NiCl2 to PdCl2/PVP using a parallel high-throughput screening technique. A wide range of aryl bromides bearing a variety of functional groups was evaluated. 相似文献
11.
This study develops a new efficient pathway for synthesis of 2,4-disubstituted 1,2,3-triazoles through regioselective direct arylation between 2-aryl-1,2,3-triazole N-oxides and Ar-B(OH)2. The reaction proceeds smoothly at room temperature and exhibits good yield and high C5 position selectivity. The possible pathway of oxidative Suzuki coupling is also discussed. This simple methodology can be used to construct 2,4-disubstituted 1,2,3-triazole moiety. 相似文献
12.
The Suzuki coupling was carried out using a new, efficient and reusable polymer-supported Pd/IL catalyst (PEt@IL/Pd) under aqueous conditions. This catalyst was prepared through coacervation approach followed by treatment with Pd(OAc)2. The FT-IR, SEM, TGA, TEM, XPS, ICP and EDX techniques were employed to characterize the PEt@IL/Pd. This catalyst exhibited high activity in the Suzuki coupling reaction under green conditions. Moreover, the catalyst could be recycled and reapplied for six times with no appreciable loss in its activity. The leaching test also showed high stability of catalytic Pd species under applied conditions. 相似文献
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Mohammad Joshaghani Marzieh Daryanavard Ezzat Rafiee Jianliang Xiao 《Tetrahedron letters》2007,48(11):2025-2027
The biphenyl-based phosphine, P(o-C6H4C6H4Me)Ph2, is a moderately bulky and electron-rich phosphine, which has been successfully applied to the palladium catalyzed Suzuki coupling of activated and deactivated aryl halides as well as bromoarylphosphines and bromoarylphosphine oxides, with low catalyst loading and good to excellent conversions and turnovers. 相似文献
14.
《应用有机金属化学》2017,31(4)
A green method for the synthesis of supported Pd nanoparticles (NPs) using pine needle extract as the reducing agent and the extracted residue of pine needle (RPN) as the carrier is described. The Pd/RPN nanocomposites were characterized using Fourier transform infrared, UV–visible, inductively coupled plasma atomic emission and X‐ray photoelectron spectroscopies, transmission electron microscopy and X‐ray diffraction. The spherical Pd NPs had a mean particle size of 3.25 nm and were evenly distributed on the RPN surface. More importantly, the Pd/RPN nanocomposite, as a heterogeneous catalyst, presented superior catalytic activity for the Suzuki coupling reaction. The yield of the reaction of 4‐bromotoluene with phenylboronic acid catalyzed by Pd0.03/RPN reached 98% with low Pd loading (0.1 mmol%) at room temperature for 30 min. In addition, the catalyst could be easily separated by centrifugation and reused at least six times without significant loss of activity. 相似文献
15.
A CuI-catalyzed Suzuki cross-coupling reaction of organoboron derivatives with alkynyl bromides has been developed. In the presence of CuI (10 mol %) and 8-hydroxyquinoline (20 mol %), organoboron derivatives including aromatic and alkenyl boronic acids, potassium aryltrifluoroborates, and sodium tetraphenylborate reacted smoothly with 1-bromo-2-substituted acetylene to generate the corresponding cross-coupling products in good to excellent yields in C2H5OH. It is important to note that aromatic N,O-ligand 8-hydroxyquinoline is the most effective ligand for the reaction. 相似文献
16.
Four natural chalcones bearing prenyl or geranyl groups, i.e., isobavachalcone (1), bavachalcone (2), xanthoangelol (3), and 2′,4′,4-trihydroxy-5′-geranylchalcone (isoxanthoangelol, 4) were synthesized by using a regio-selective iodination and the Suzuki coupling reaction as key steps. Among them, the first total synthesis of 2′,4′,4-trihydroxy-5′-geranylchalcone was achieved in 36% overall yield. Comparing with the reported methods based on C-alkylation or O-alkylation followed by Claisen rearrangement to introduce the side chain, this new strategy capitalizes on a precious regiochemical control during iodination. The overall yields for the synthesis of the first three chalcones were improved from 17% to 53%, 12% to 35%, and 28% to 50%, respectively. 相似文献
17.
N-aryl bromodifluoroacetimidoyl halides were prepared by the reaction of bromodifluoroacetic acid, triphenyl phosphine, p-arylaniline and triethylamine in tetrachloromethane in good yields. Palladium-catalyzed cross-coupling reaction of N-aryl bromodifluoroimidoyl iodide with arylboronic acids was realized to afford bromodifuoromethyl ketimine in good yields. 相似文献
18.
Amanda P. Skoumbourdis Susanna Moore Marc Landsman Craig J. Thomas 《Tetrahedron letters》2007,48(52):9140-9143
Substitutions on the 2-position of the imidazole ring of histamine have proven useful in a number of biochemical settings. Current art for the synthesis of these constructs relies upon a cumbersome and low-yielding condensation reaction. Here-in we report a new procedure for the synthesis of a series of substituted 2-phenylhistamines utilizing a microwave-promoted Suzuki coupling. 相似文献
19.
Akio Ojida 《Tetrahedron letters》2005,46(19):3301-3305
Suzuki-coupling, a representative cross-coupling reaction between small molecules, can proceed on a protein surface in aqueous solution under mild conditions. The modified protein produced by the coupling reaction maintained its native like structure and function. In addition, fluorescent dye appended-protein acts as a fluorescent biosensor. 相似文献
20.
A variety of fluorinated biphenyl derivatives were obtained in good yields in aqueous solvents at room temperature by Suzuki coupling reaction of aryl bromides and aryl boronic acid in the presence of high activity catalyst—some air-stable hemilabile PO coordinated cyclopalladated complexes. The structures of above catalysts were characterized by element analyses, IR, 1H NMR, 13C NMR and 31P NMR. 相似文献