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1.
An ultrafast and highly efficient ligand-free Suzuki-Miyaura cross-coupling reaction between aryl bromides/iodides and arylboronic acids using palladium chloride as catalyst in PEG400/H2O in air at room temperature has been developed. TEM showed that palladium nanoparticles were generated in situ from PdCl2/PEG400/H2O without use of other reductants. The catalyst system can be recycled to reuse three times with good yields. 相似文献
2.
A series of unsymmetrical 1,3-disubstituted benzimidazolium chlorides were synthesized as N-heterocyclic carbene (NHC) precursors. These compounds were used to synthesize of the PEPPSI-type palladium NHC complexes. The structures of all compounds were characterized by 1H NMR, 13C NMR, FT-IR spectroscopy and elemental analyses. The catalytic activity of the PEPPSI-type palladium–NHC complexes has been evaluated with respect to the Suzuki-Miyaura cross-coupling reactions of phenyl boronic acid with various aryl halides in aqueous media. 相似文献
3.
A salen-type palladium(II) complex was readily immobilised onto a Merrifield resin. The supported complex is an effective recyclable heterogeneous catalyst for the Suzuki cross-coupling reaction without the use of phosphine ligands. Leaching of the metal into solution from the supported catalyst proved negligible. 相似文献
4.
For the first time, palladium complexes with salicylaldehyde thiosemicarbazones were applied as catalyst precursors to the Suzuki-Miyaura reaction. These air and moisture stable phosphine-free systems efficiently catalyze the cross-coupling of aryl bromides and chlorides (from electron rich to electron poor) with phenylboronic acid in DMF/H2O at 100 °C for 24 h, using Na2CO3 as base, without addition of free ligand or any promoting additive, and under aerobic conditions no significant homocoupling of phenylboronic acid to unsubstituted biphenyl was observed. 相似文献
5.
Kamal M. Dawood 《Tetrahedron》2007,63(39):9642-9651
The catalytic activity of benzothiazole-based Pd(II)-complexes was evaluated in Suzuki-Miyaura and Heck-Mizoroki C-C cross-coupling reactions of aryl chlorides and bromides with olefins and arylboronic acids both under thermal as well as microwave irradiation conditions in water. The factors affecting the optimization of such reactions as well as the reusability of the Pd-precatalysts are studied. 相似文献
6.
Michael Nonnenmacher Frank Rominger Thomas Oeser 《Journal of organometallic chemistry》2007,692(12):2554-2563
The synthesis and characterization of new bidentate N-heterocyclic carbene ligands is described. The ligands are derived from methylene (me) and ethylene (et) bridged imidazo[1,5-a]pyridine-3-ylidenes (impy) and can be synthesized readily from imidazo[1,5-a]pyridine and the respective dihaloalkanes. Palladium(II) dihalide complexes bearing these et(impy)2 or me(impy)2 ligands were prepared and also structurally characterized. The angle of the impy plane vs. the C-Pd-C plane is depending on the bridging unit as well as the halide ligands. In the solid state the me(impy)2PdBr2 complex forms a dimer by weak intermolecular Pd-hydrogen bridges. The activity of the Pd-complexes as catalysts for the Heck and Suzuki-Miyaura reactions was tested under various conditions. The catalysts show good activity at 120 °C in Heck and at 85 °C in Suzuki-Miyaura reactions. 相似文献
7.
Ping Liu 《Tetrahedron》2010,66(3):631-122
Salen and half-salen palladium(II) complexes (salden)Pd (1, salden=N,N′-bis(3,5-di- tert-butylsalicylidene)-1,2-dimethylethylenediamine), (hsalph)PdCl (2, hsalph=3,5-di-tert- butylsalicylidene-1-iminophenylene-2-amine), and (salph)Pd (4, salph=N,N′-bis(3,5-di-tert- butylsalicylidene)-1,2-phenylenediamine) were prepared and structurally characterized by X-ray crystallography. Complex 2 proved to exhibit high catalytic activity toward Suzuki-Miyaura reaction. Polyaromatic C3-symmetric derivatives and various fluorinated biphenyl derivatives were readily achieved in good yields using Suzuki-Miyaura reaction catalyzed by complex 2. 相似文献
8.
Ioannis D. Kostas Athanassios G. Coutsolelos Georgios Charalambidis 《Tetrahedron letters》2007,48(38):6688-6691
For the first time, a palladium complex with a porphyrin ligand is used as a catalyst precursor for cross-coupling reactions. The synthesis of a palladium complex with a phosphine-free and water-soluble potassium carboxylate salt of a porphyrin, and its evaluation in the Suzuki-Miyaura reaction of phenylboronic acid with aryl bromides (from electron-rich to electron-poor), in neat water, under aerobic conditions is described. Catalysis is performed at 100 °C for 4 h, using K2CO3 as base, and a substrate to catalyst molar ratio of 1000:1, leading to yields of coupling products in the range of 80-100%. The catalyst can be recycled and reused, but unfortunately, with a loss in activity. 相似文献
9.
A novel cis-chelated Pd(II)-NHC complex for catalyzing Suzuki and Heck-type cross-coupling reactions
A novel Pd(II)-NHC complex, which has a ‘normal’ cis-chelating, bidentate structure is fairly effective in Suzuki and Heck-type cross-coupling reaction to give the products in good to excellent yields in most cases. 相似文献
10.
Ioannis D. Kostas Georgios A. Heropoulos Dimitra Kovala-Demertzi Paras N. Yadav Mavroudis A. Demertzis Giang Vo-Thanh André Loupy 《Tetrahedron letters》2006,47(26):4403-4407
A new air- and moisture-stable palladium complex with salicylaldehyde N(4)-hexamethyleneiminylthiosemicarbazone has been synthesized. According to its crystal structure, the metal is bonded to 2 equiv monoanionic thiosemicarbazone moieties in a N,S-bidentate fashion, forming two five-membered chelate rings, while additional intramolecular bonds stabilize the structure. In contrast to other palladium complexes with thiosemicarbazones, this complex was inactive towards the Suzuki-Miyaura coupling under aerobic conditions, by conventional heating. On the other hand, microwave irradiation promoted the effective catalytic activity of the complex for the coupling of aryl bromides and chlorides with phenylboronic acid in DMF/H2O, under aerobic conditions, with turnover numbers of up to 37,000. 相似文献
11.
Four air- and moisture-stable new palladium(II) complexes 2a–2c and 4 have been synthesized from easily available 2-arylnaphthoxazole derivatives. The detailed structures of 2c and 4 have been determined by single-crystal X-ray analysis. The Pd–N, Pd–C bonds in palladacycle complexes 2a–2c and the Pd–N, Pd–O bonds in complex 4 form the basis for five- and six-membered chelate rings, respectively. These complexes were applied as efficient phosphine-free catalysts for Heck reactions with aryl bromides and ethyl acrylate. Typically, in the presence of two equivalent n-Bu4NBr, using 0.01% of palladacycle complex 2c as catalyst and two equivalent of K2CO3 as base in DMF at 140 °C provided coupled products in moderate to high yields. 相似文献
12.
Polyaniline supported palladium catalysts were prepared from different palladium precursors and all the catalysts are well characterized using ICP-AES, FTIR, TGA-DTA, SEM-EDX and XPS analysis. All the catalysts were tested for Suzuki-Miyaura coupling of bromo- and chloroarenes in water and the catalyst prepared from PdCl2 precursor was found to be the most effective catalyst. The catalyst can easily be recovered by simple filtration and reused for several cycles with almost consistent activity. 相似文献
13.
Anna Komáromi 《Tetrahedron letters》2010,51(41):5411-1967
Comparison of the activity of several commercially available Pd/C catalysts in C-C, C-N, and C-S bond forming cross-coupling reactions has demonstrated the importance of the choice of the catalyst source. Investigations showed marked difference in activity between the catalysts. Moreover, the catalytic activity of each catalyst varies with respect to the coupling. The first Pd/C catalyzed Hiyama coupling is reported. 相似文献
14.
Lin-Yan Xu Chun-Yu Liu Shi-Yuan Liu Zhi-Gang Ren David James Young Jian-Ping Lang 《Tetrahedron》2017,73(22):3125-3132
One palladium dichloride adduct of a phosphine-pyridine ligand N-diphenylphosphanyl-2-aminopyridine (L1) [(L1)PdCl2] (1) has been prepared and structurally characterized. Compound 1 can be used as an effective catalyst for the Suzuki-Miyaura cross-coupling reactions of unreactive aryl chlorides with aryl boronic acids, and worked much better than its mono- or bidentate phosphine ligands. The reactions with a wide scope of substrates proceeded to give desired products in good to excellent yields. 相似文献
15.
《Journal of Coordination Chemistry》2012,65(11):1910-1921
AbstractA family of five palladium(II) 2-(arylazo)naphtholate complexes, [PdCl(PPh3)(L)] (L?=?O, N-donor of bidentate 2-(arylazo)naphtholate ligands), have been synthesized and characterized by elemental analysis and spectral (FT-IR, UV–Vis, 1H-NMR and 13C-NMR) methods. Further, the catalytic efficiency of all the complexes have been investigated for Suzuki and Sonogashira coupling reaction of various aryl halides. 相似文献
16.
Monomeric triphenylphosphite palladacycles with N-imidazole ligands as catalysts of Suzuki-Miyaura and Sonogashira reactions 总被引:1,自引:0,他引:1
Izabela B?aszczyk 《Journal of organometallic chemistry》2011,696(23):3601-3607
Three monomeric triphenylphosphite palladacycles of the formula [PdCl(P-C)(im)], where P-C = P(OC6H4)(OC6H5)2, im = 1-methylimidazole, 2, 1,2-dimethylimidazole, 3, and 1-butylimidazole, 4, were obtained in reaction of [PdCl(P-C)]2, 1, with the respective imidazoles. These complexes exhibited high catalytic activity in the Suzuki-Miyaura reaction in ethane-1,2-diol and in the Sonogashira reaction in ionic liquids, [bmim]BF4 and [bmim]PF6. While the application of two imidazoles per palladium caused improvement of the reaction yield, an inhibiting effect was found in both reactions when 1-methylimidazole or 1-butylimidazole was used in 20-fold excess relative to palladium. 相似文献
17.
Rui Zhong 《Journal of organometallic chemistry》2011,696(9):1703-11051
Seven tripodal imidazolium salts were synthesized and used as catalyst precursors in cross-coupling reactions of aryl halides with arylboronic acids. Effect of counterions and central cores of seven tripodal imidazolium salts was investigated. The tripodal imidazolium salt anchored to benzene with anion PF6− was found most effective with Pd(OAc)2 for the cross-coupling of aryl bromides with arylboronic acids. 相似文献
18.
A novel tridentate NHC-Pd(II) complex derived from binaphthyl-2,2′-diamine (BINAM) has been synthesized and its structure has been characterized by single crystal X-ray diffraction. This NHC-Pd(II) complex was fairly effective in Suzuki and Heck-type cross-coupling reactions to give the products in good to excellent yields in most cases. 相似文献
19.
Five non-symmetrical PCN pincer palladium(II) complexes [PdCl{C6H3-2-(CHNR)-6-()}] (R = m-ClC6H4, R′ = Ph (2a); R = Ph, R′ = Ph (2b); R = i-Pr, R′ = Ph (2c); R = m-ClC6H4, R′ = i-Pr (2d); R = (S)-1-phenylethyl, R′ = Ph (2e)) have been easily prepared in only two steps from readily available m-hydroxybenzaldehyde and characterized by HRMS, 1H NMR, 13C NMR, 31P NMR and IR spectra. The molecular structures of 2a and 2b have been further determined by X-ray single-crystal diffraction. The obtained Pd complexes were found to be effective catalysts for the Suzuki and copper-free Sonogashira cross-coupling reactions which could be carried out in the undried solvent under air. 相似文献
20.
Nam T.S. Phan 《Tetrahedron》2005,61(51):12065-12073
A polymer-supported palladium(II) salen-type complex exhibited catalytic activity in the cross-coupling reaction of various aryl bromides and heteroaryl bromides with phenylboronic acid in a mini-continuous flow reactor system at elevated temperatures in a phosphine-free system. The reaction was also performed in batch using a number of different solvent systems in order to optimise conditions. The catalytic mini-reactor can be used repeatedly over several cycles in the Suzuki-Miyaura cross-coupling reaction. While the diameter of the flow channel is 3 mm, the macroporous resin supported catalyst is solvent expanded to completely fill the channel. Consequently, the liquid path is through the micro channels of the macroporous resin structure. Intensification of the process over the stirred batch reaction is through increased reagent-catalyst contact and results in a 20-fold increase in the rate of reaction. The residence/space time on the reactor is 10.5 min, compared to 24 h in batch, which means that a diversity of starting materials can be screened over a short period of time. To demonstrate the utility of the system, a diversity of aryl and heteroaryl bromides have been studied. 相似文献