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1.
Catalytic activity of 1‐methylimidazole‐based phosphine ligands in the palladium‐catalyzed Suzuki coupling reaction
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The catalytic activities of three N‐methylimidazole‐based phosphine ligands in the Suzuki coupling reaction were tested using PdCl2 as the catalyst. The results showed all three phosphine ligands exhibited excellent activity towards the Suzuki reaction, and the catalytic activity decreased with increasing number of imidazole groups. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
2.
M. Emre Hanhan 《应用有机金属化学》2008,22(5):270-275
A range of sterically hindered diimine ligands and their palladium (II) complexes were synthesized. These compounds were fully characterized by elemental analysis, 1H and 13C‐NMR spectroscopy. The use of the palladium complexes as catalysts for Suzuki and Heck coupling has been studied in an attempt to demonstrate the effect of side groups on catalytic activity. It was clearly seen that the location of side ? CH3 groups which bound to benzene ring had little effect on catalytic activity. Interestingly when we changed these ? CH3 groups with ? Cl groups the activity of the complexes increased. On the other hand, side groups which bound to imine nitrogen also had a large effect on catalytic activity. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
3.
An efficient and recyclable protocol for the Suzuki reaction in water has been developed based on the cloud point of thermoregulated ligand Ph2P(CH2CH2O)nCH3 (n = 22). This method allows the preparation of a variety of biaryls in high yields and the catalytic system can be recycled four times with high efficiency. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
4.
A complex of [BMIm] PF6 (1‐Butyl‐3‐methylimidazolium hexafluorophosphate) with PEG1000 has been successfully applied and found to be efficient for Suzuki cross‐coupling and Heck reaction using Pd(OAc)2 as the catalyst under air atmosphere. Moreover, the isolation of the products is readily performed by the extraction of diethyl ether, and the catalytic system reported here can be recycled and reused several times. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
5.
In water, ammonium chloride was found to promote palladium-catalyzed Ullmann coupling reactions of aryl bromides. In the presence of Pd/C, zinc, NH4Cl, and water, coupling of various aryl bromides was carried out smoothly to afford the corresponding homocoupling products in moderate yields. 相似文献
6.
A practical heterogeneous palladium‐catalyzed carbonylative Suzuki coupling of aryl iodides with arylboronic acids under carbon monoxide gas‐free conditions has been developed using a bidentate phosphino‐functionalized magnetic nanoparticle‐immobilized palladium(II) complex as catalyst. Formic acid was utilized as the carbon monoxide source with dicyclohexylcarbodiimide as the activator, and a wide variety of biaryl ketones were generated in moderate to high yields. The new heterogeneous palladium catalyst can be prepared via a simple procedure and can easily be separated from a reaction mixture by simply applying an external magnet and recycled up to 10 times without any loss of activity. 相似文献
7.
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
8.
Palladium‐anchored multidentate SBA‐15/di‐urea nanoreactor: A highly active catalyst for Suzuki coupling reaction
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Sahar Rohani Ghodsi Mohammadi Ziarani Alireza Badiei Abolfazl Ziarati Maryam Jafari Alireza Shayesteh 《应用有机金属化学》2018,32(8)
Modification of mesoporous silica was carried out by reaction of SBA‐15 with di‐urea‐based ligand. Next, with the help of this ligand, palladium ions were anchored within the multidentate SBA‐15/di‐urea pore channels with high dispersion. The SBA‐15/di‐urea/Pd catalyst was characterized using various techniques. Theoretical calculations indicated that each palladium ion was strongly interacted with one nitrogen and two oxygen atoms from the multidentate di‐urea ligand located in SBA‐15 channels and these interactions remained during the catalytic cycle. These results are in good agreement with those of hot filtration test: the palladium ions have very high stability against leaching from the SBA‐15/di‐urea support. The catalytic performance of SBA‐15/di‐urea/Pd nanostructure was examined for the Suzuki coupling reaction of phenylboronic acid and electronically diverse aryl halides under mild conditions with a minimal amount of Pd (0.26 mol%). Compared to previous reports, this protocol afforded some advantages such as short reaction times, high yields of products, catalyst stability without leaching, easy catalyst recovery and preservation of catalytic activity for at least six successive runs. 相似文献
9.
The palladium‐catalyzed C‐N cross‐coupling reaction of diheteroaryl disulfides with heterocyclic amines
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The Pd‐catalyzed cross‐coupling reaction of 1, 2‐di(pyrimidin‐2‐yl) disulfides with heterocyclic amines including 2‐amino pyrimidines and 1,3,4‐thiadiazol‐2‐amines to deliver symmetrical C‐N coupling products in moderate to good yields is reported. This method provides an opportunity for synthesis of bioactive molecules and pharmaceutically interesting compounds containing heterocycle motifs. The reported protocol shows good functional group compatibility, and provides a new strategy for preparation of C2‐amination pyrimidine derivatives from heterocyclic disulfides. 相似文献
10.
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
11.
12.
A highly efficient and mild palladium‐catalyzed cross‐coupling of arylsulfonyl hydrazides and aryl bromides for the selective synthesis of unsymmetrical biaryls has been developed. This methodology has the advantages of easily accessible starting materials, functional group tolerance and a wide range of substrates, which provide rapid access to biaryls derivatives. In this protocol, abundant and stable aryl bromides serve as the aryl sources by coupling reaction of the aryl group generated from arylsulfonyl hydrazides via in situ release of nitrogen and sulfur dioxide. No external oxidants or acids are needed for this kind of transformation. 相似文献
13.
A new catalyst, Pd particles supported on the N-doped porous carbon(PC) derived from Zn-based metal–organic frameworks(zeolitic imidazolate framework: ZIF-8), was successfully prepared for the first time.The as-prepared catalyst was designated as N-doped PC-Pd, and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscope, N_2 adsorption and inductively coupled plasma atomic emission spectroscopy. The N-doped PC-Pd composite exhibited high catalytic activity toward the Suzuki–Miyaura cross-coupling reactions. The yields of the products were in the range of 90%–99%. The catalyst could be readily recycled and reused at least 6 consecutive cycles without a significant loss of its catalytic activity. 相似文献
14.
In-situ synthesis of a palladium-polyaniline hybrid catalyst for a Suzuki coupling reaction 总被引:1,自引:0,他引:1
Rafique Ul Islam Elma van der Lingen Willem Van Otterlo 《Journal of organometallic chemistry》2011,696(10):2206-132
Palladium-catalyzed cross-coupling reactions are one of the most frequently used synthetic tools for the construction of new carbon-carbon bonds in organic synthesis. The present study describes the use of palladium-polyaniline composite material as a catalyst for the Suzuki coupling of aryl halides. Palladium-polyaniline nanocomposite material was synthesized using an in-situ technique in which palladium acetate and aniline hydrochloride were used as the precursors of the composite. Electron microscopy imaging showed that the palladium particles were well-dispersed within the polymer matrix and were typically 3-5 nm in diameter. The metal-polymer composite material was used as a catalyst for the coupling of phenylboronic acid with aryl halides in the presence of an inorganic base and showed excellent yield with high TOF values. 相似文献
15.
N‐Heterocyclic carbene/phosphite synergistically assisted Pd/C‐catalyzed Suzuki coupling of aryl chlorides
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An N‐heterocyclic carbene and phosphite synergistically enhanced Pd/C catalyst system has been developed for Suzuki coupling of aryl chlorides and aryl boronic acids from commercially available Pd/C with sterically demanding N,N′‐bis(2,6‐diisopropylphenyl)imidazolylidene and trimethylphosphite. A remarkable increase in catalytic activity of Pd/C was observed when used along with 1 equiv. N,N′‐bis(2,6‐diisopropylphenyl)imidazolium chloride and 2 equiv. phosphite with respect to palladium in appropriate solvents that were found to play a crucial role in Pd/C‐NHC‐P(OR)3‐catalyzed Suzuki coupling. A dramatic ortho‐substitution effect of carbonyl and nitrile groups in aryl chlorides was observed and explained by a modified quasi‐heterogeneous catalysis mechanism. The Pd/C catalyst could be easily recovered from reaction mixtures by simple filtration and only low palladium contamination was detected in the biparyl products. A practical process for the synthesis of 4‐biphenylcarbonitrile has therefore been developed using the N‐heterocyclic carbene/phosphite‐assisted Pd/C‐catalyzed Suzuki coupling. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
16.
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
17.
Noora Kuuloja Tuula Kylmälä Youjun Xu Robert Franzén 《Central European Journal of Chemistry》2008,6(3):390-392
Xenbucin 1, an analgesic drug, was synthesized in 4 steps using two different routes. The biaryl fragment could successfully be produced
via a Pd/C catalysed Suzuki coupling in water using sodium tetraphenylborate as a phenylation reagent. Overall yields of the
routes were 36% and 59%, respectively.
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18.
A comparison between two Pd‐Ni catalysts supported on two different supports toward Suzuki‐Miyaura coupling reaction
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When a single metal fails to promote an efficient Suzuki‐Miyaura coupling reaction at ambient temperature, the synergistic cooperation of two distinct metals might improve the reaction. To examine the synergistic effect of palladium and nickel for catalyzing Suzuki coupling reaction, g‐C3N4 supported metal nanoparticles of PdO, NiO and Pd‐PdO‐NiO were prepared, characterized and their catalytic activities evaluated over different aryl halides at room temperature and 78 °C. The morphological characterization of Pd‐PdO‐NiO/g‐C3N4 demonstrated that the bimetallic particles were uniformly dispersed over the g‐C3N4 layers with diameters ranging from 3.5‐7.7 nm. XPS analysis showed that nanoparticles of Pd‐PdO‐NiO consisted of Pd(II), Pd(0) and Ni(II) sites. The experiments performed on the catalytic activity of Pd‐PdO‐NiO/g‐C3N4 showed that the prepared catalyst demonstrated an efficient activity without using toxic solvents. 相似文献
19.
《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
20.
Synthesis,characterization and catalytic activity of new aminomethyldiphosphine–Pd(II) complexes for Suzuki cross‐coupling reaction
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A new range of CF3‐substituted aminomethyldiphosphine (P―C―N) ligands ((C6H5)2PCH2)2NR (R = ―C6H4(2‐CF3) ( 1 ), ―C6H4(3‐CF3) ( 1b ) has been synthesized from 2‐(trifluoromethyl)aniline and 3‐(trifluoromethyl)aniline with diphenylphosphine. The aminomethyldiphosphine ligands were reacted with Pd(cod)Cl2 to give corresponding metal complexes, PdLCl2 ( 2a , 2b ). The aminomethyldiphosphine–palladium compounds were characterized by utilizing several methods including NMR (1H, 13C, 31P) and elemental analysis. These compounds were used as catalysts in Suzuki cross‐coupling reaction of aryl chlorides and bromides. The effect of base was also investigated in this current project. CF3‐substituted aminomethyldiphosphine–palladium complexes were found to be efficient catalysts in Suzuki cross‐coupling reaction of activated and deactivated aryl boronic acids. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献