- A simple method for preparing imidazolium-based polymer as solid catalyst for Suzuki-Miyaura reaction
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Polymers containing the structure of N-heterocyclic carbenes (NHCs) have attracted much interest due to their superior complexing ability to metal ions and good recyclability, which make them promising candidates as solid supporters. Herein, we developed an easy method to synthesize polyimidazolium chloride salt (PImCl) via one-step method in mild conditions. After PImCl was chelated with palladium chloride in 3-chloropyridine, this NHC-Pd polymer was employed as the solid catalyst for Suzuki reactions of aryl bromides and phenylboronic acid. The catalytic activity of the NHC-Pd polymer was high for many different substrates. Moreover, the Suzuki reaction of 4-bromoanisole with phenylboronic acid could be catalyzed by this NHC-Pd polymer in mild conditions. Furthermore, this solid catalyst could be easily isolated by centrifugal separation. After several recycling runs, the catalytic activity decreased little. Compared with the conventional methods, this method was much simpler and more efficient, which showed enormous potential in preparing new heterogeneous supporter of porous polyimidazolium chloride salt.
- Zhang, Weiqiang,Peng, Liangyi,Deng, Chunyan,Zhang, Yingxue,Qian, Hao
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- Enhancement of Suzuki–Miyaura coupling reaction by photocatalytic palladium nanoparticles anchored to TiO2 under visible light irradiation
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Plasmonic property and catalytic performance of Pd anchored to TiO2 for Suzuki?Miyaura coupling (SMC) reactions are reported. Different from previous reports, this semiconductor with band gap ≥3 eV can afford C–C bond formation for SMC. Nano Pd/TiO2 was successfully synthesized through a photodeposition method under sunlight. The size of Pd nanoparticles onto the surface of TiO2 led to enhancement of localized surface plasmon resonance. This visible-light-harvesting heterogeneous photocatalyst sufficiently promoted substrates toward coupling reaction products at ambient temperature in aqueous media. Photo-generated electron-hole pairs under visible light irradiation, are the key components of activation of the substrates.
- Koohgard, Mehdi,Hosseini-Sarvari, Mona
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- Decarbonylative Suzuki-Miyaura Cross-Coupling of Aroyl Chlorides
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Herein, we report a catalyst system for Pd-catalyzed decarbonylative Suzuki-Miyaura cross-coupling of aroyl chlorides with boronic acids to furnish biaryls. This strategy is suitable for a broad range of common aroyl chlorides and boronic acids. The synthetic utility is highlighted in the direct late-stage functionalization of pharmaceuticals and natural products capitalizing on the presence of carboxylic acid moiety. Extensive mechanistic and DFT studies provide key insight into the reaction mechanism and high decarbonylative cross-coupling selectivity.
- Zhou, Tongliang,Xie, Pei-Pei,Ji, Chong-Lei,Hong, Xin,Szostak, Michal
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supporting information
p. 6434 - 6440
(2020/09/02)
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- Efficient Catalyst for Both Suzuki and Heck Cross-Coupling Reactions: Synthesis and Catalytic Behaviour of Geometry- Constrained Iminopyridylpalladium Chlorides
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A series of geometry-constrained iminopyridyl-palladium chlorides were synthesized and characterized. These phosphine-free palladium complexes were explored for their catalytic activities in both Suzuki and Heck cross-coupling reactions, achieving turnover numbers as high as 106towards various aryl bromides, even those containing various functionalities. In addition, the influence of substituents with steric and electronic factors was reflected by the differences observed in their activities. (Figure presented.).
- Tang, Yujie,Zeng, Yanning,Hu, Qingxia,Huang, Fang,Jin, Liqun,Mo, Weimin,Sun, Nan,Hu, Baoxiang,Shen, Zhenlu,Hu, Xinquan,Sun, Wen-Hua
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p. 2642 - 2651
(2016/08/31)
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- Biguanide/Pd(OAc)2 immobilized on magnetic nanoparticle as a recyclable catalyst for the heterogeneous Suzuki reaction in aqueous media
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Immobilization of Pd(II) ions on magnetite nanoparticle (MNP) has been simply achieved through a surface modification of Fe3O4 nanoparticle with a biguanide. This surface-modified nanoparticle was characterized by various techniques such as TEM, XRD, VSM, TGA, elemental analyzer, atomic absorption spectroscopy, N2 adsorption-desorption (BET and BJH), and FT-IR. This nanosolid exhibits excellent catalytic activity for heterogeneous Suzuki reaction in aqueous media, and could be easily separated by an external magnet and reused for several times. TEM study of the recovered catalyst showed the preservation of the support core-shell structure and the good dispersion of the produced palladium nanoparticles.
- Beygzadeh,Alizadeh,Khodaei,Kordestani
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- Highly efficient phosphine-free Suzuki aryl couplings mediated by an in situ generated Pd(OAc)2/metformin complex in green media
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An in situ generated complex of palladium(II) and a biguanide, namely metformin, was found to be a highly efficient homogeneous catalyst for the phosphine-free Suzuki-Miyaura reaction. Significant rate acceleration of the palladium-catalyzed coupling was observed when a 1:1 mixture of ethanol/water was employed as the reaction solvent. Using this protocol, a variety of aryl halides (Cl, Br, I) were subjected to reaction with various arylboronic acids and the products were obtained in good to excellent yields under mild reaction conditions.
- Alizadeh,Khodaei,Kordestani,Beygzadeh
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p. 291 - 294
(2013/02/23)
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- A biguanide/Pd-decorated SBA-15 hybrid nanocomposite: Synthesis, characterization and catalytic application
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A stable palladium-decorated SBA-15 nanocomposite was simply fabricated through surface modification of SBA-15 with biguanide and subsequent metal/ligand coordination with Pd2+ from inexpensive commercially available starting materials and using standard laboratory techniques. The structure of this organic inorganic hybrid material was characterized by SEM, TEM, XRD, elemental analyzer, atomic absorption spectroscopy, N2 adsorption-desorption (BET), and FT-IR techniques. The catalytic performance of this novel heterogeneous catalyst was determined for the Suzuki cross-coupling and aerobic oxidation of benzyl alcohols. The composite exhibited an excellent catalytic activity and reuse ability of various recycles in air for the aforementioned organic transformations. TEM images of the recovered catalyst showed retained ordered mesostructure of SBA-15 with no damage in the periodic structure of the silicate framework and a good dispersion of in situ generated palladium nanoparticles within the SBA-15 structure.
- Alizadeh,Khodaei,Kordestania,Beygzadeh
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p. 167 - 174
(2013/05/08)
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- Canopied trans-chelating bis(N-heterocyclic carbene) ligand: Synthesis, structure and catalysis
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The terphspan scaffold was employed to support a bis(N-heterocyclic carbene) ligand (1) that provides a m-terphenyl canopy over one side of its metal complexes. Single-crystal X-ray diffraction studies on a silver complex of {[Ag(1)]AgBr2}2 revealed an unusual tetranuclear silver core with a Ag-Ag bond distance of 3.0241(8) with 1 as a trans-chelating ligand (C-Ag-C = 171°). A preliminary X-ray structure of pseudo-square planar [PdCl2(1)] showed a similar binding mode of 1 (C-Pd-C = 177°). High yields were obtained in Suzuki-Miyaura coupling reactions utilizing [PdCl2(1)] as the procatalyst and the results were compared with analogous complexes of trans-spanning diphosphine (2) and diphosphinite (3) complexes. The diphosphinite complex, [PdCl2(3)], decomposes to [μ-ClPd(PPh2OH)(PPh2O)]2 at room temperature. The Royal Society of Chemistry 2009.
- Morgan, Brad P.,Galdamez, Gabriela A.,Gilliard Jr., Robert J.,Smith, Rhett C.
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experimental part
p. 2020 - 2028
(2009/05/15)
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- PEG (300)-PdCl2 promoted efficient and convenient Suzuki-Miyaura coupling of aryl chlorides with arylboronic acids
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PEG (300) was found as an effective medium for the PdCl2-catalyzed Suzuki-Miyaura cross-coupling of aryl chlorides with various phenylboronic acids. This cross-coupling pathway conveniently and efficiently gave good to excellent yields of corresponding biaryl nucleus under mild conditions.
- Yin, Liang,Zhang, Zhan-hui,Wang, Yong-mei
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p. 9359 - 9364
(2007/10/03)
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- METHOD FOR CARRYING OUT CHEMICAL REACTIONS INVOLVING COMPOUNDS ADSORBED ON FLUORINATED CARRIER MATERIALS BY MEANS OF FLUORINE-FLUORINE INTERACTIONS
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The invention relates to a method for carrying out a chemical reaction of a compound (B), involving a compound (A-F) which is adsorbed on a fluorinated carrier material (FT) by means of fluorine-fluorine interactions, forming an addition compound (A-F):(FT). The inventive method is characterised in that said addition compound (A-F):(FT) is suspended in a suitable solvent containing the compound B, whereby said compound B is reacted to form the reaction product B', in the presence of the adsorbed compound A-F.
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Page/Page column 25-27
(2008/06/13)
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- Fluorous biphasic catalysis without perfluorinated solvents: Application to Pd-Mediated Suzuki and Sonogashira couplings
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With and now without: Perfluoro-tagged catalysts immobilized on fluorous reversed-phase silica gel can be used for Suzuki and Sonogashira C-C coupling reactions (see scheme; R1 = e.g., phenyl, 4-MeOC6H4, R2 e.g., 4-NO2C6H4, 4-MeCOC6H4, X = Br, I) without the need for perfluorinated solvents. After the reaction the products were isolated by decantation and the Pd catalysts were recovered and reused.
- Tzschucke, Carl Christoph,Markert, Christian,Glatz, Heiko,Bannwarth, Willi
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p. 4500 - 4503
(2007/10/03)
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- Difluorooxymethane derivative and liquid crystal composition
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In order to provide novel compounds which are useful as liquid crystal materials for low voltages in several liquid crystal displays, have a large dielectric anisotropy, and are low in viscosity; and to improve characteristics of liquid crystal compositio
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- Homolytic Reactions of Polyfluoroaromatic Compounds. Part 16. Competitive Phenylation of Polyfluorobenzenes
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Pairs of polyfluorobenzenes were allowed to compete for phenyl radicals generated by thermolysis of benzoyl peroxide at 80 deg C.From the relative yields of biaryl, and the yields of each biaryl formed upon arylation of each arene individually, the relative rates of attack of each site in each arene were deduced.Neither iron(III) benzoate nor trichloroacetic acid uniformly improved yields of biaryl, although in some cases the isomer distribution altered, when decomposition of benzoyl peroxide was carried out in the presence of such additives, to favour products of aryldehydrogenation or of aryldefluorination, respectively.Competition did not usually affect the distribution of attack of a particular arene, except when hexafluorobenzene was used, in which case greater selectivity of attack of the second arene occured.This suggested the formation of a 'stabilised' phenyl radical, and supported an earlier suggestion of species such as >; other evidence also supported the postulate.
- Allen, Kim J.,Bolton, Roger,Williams, Gareth H.
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p. 691 - 696
(2007/10/02)
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