KINETICS AND CATALYSIS
·
2020
·Vol. 61
·期 3
·480-485
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IF 0.934
Zhong S.
Abstract Nanofibers are attractive supporting matrices for catalytically active metallic catalysts. Herein, palladium species were successfully incorporated into the modified chitosan/poly(ethylene oxide)/maleic acid nanofibers by electrospinning. Then, the hybrid nanofibers were thermally cross-linked at elevated temperature to improve stable behavior in solution. X-ray diffraction and transmission electron microscopy characterizations show that the palladium nanoparticles are dispersed uniformly inside the hybrid nanofibers. This novel hybrid nanofiber mat displayed high catalytic activity for the Sonogashira coupling reaction of phenyl acetylene with aromatic iodides under copper free condition with moderate to excellent yields. Moreover, this nanofiber mat could be reused 10 times with little activity loss. Thus, we have proposed a facile way to prepare highly active and stable heterogeneous palladium catalyst.
研究领域:
材料科学
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催化化学
✓ 已验证
DOI
高影响因子
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
·
2014
·Vol. 2014
·期 6
·975-985
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IF 2.965
Jing Zhang,Yongyong Wang,Xiaoli Zhao,Ye Liu
Graphical The ionic palladium complexes 1A – 4A ligated by imidazolium-based-phosphanes were prepared and shown, by single-crystal X-ray diffraction analyses, to be composed of Pd II -centered square-planar cations and OTf – counteranions. The complexes were tested as precatalysts for the homogeneous carbonylative Sonogashira coupling of aryl iodides with phenylacetylene. The stable ionic Pd II complexes 1A – 4A were synthesized through the complexation of PdCl 2 (MeCN) 2 with the phosphane-functionalized ionic liquids (FILs) 1 – 4 with π-acceptor character. Single-crystal X-ray diffraction analyses showed that 1A – 4A were all composed of Pd II -centred square-planar cations and triflate (OTf – , CF 3 SO 3 – ) counteranions. The complex cations in 1A – 3A possessed structural similarity to trans -PdCl 2 (PPh 3 ) 2 . The cation in 4A was a new Pd II -centered planar complex ligated by the phosphane–carbon anion–carbene (PCC) pincer in a tripodal manner. The stabilities of 1A – 4A were improved due to the intensive π-backbonding interaction between the Pd and P atoms. When complexes 1A – 4A were used as precatalysts for homogeneous carbonylative Sonogashira coupling of PhI with phenylacetylene free of CuI, 1A – 3A exhibited excellent catalytic behaviour with a TON of up to 1700 at a CO pressure of 0.5 MPa and moderate temperature of 100 °C, whereas 4A exhibited poor activity towards the transformation of PhI due to the high stability of 4A . The recycling experiments of 3A in [Bpy]BF 4 (as a solvent) indicated that 3A could be recycled for 5 runs with neither activity loss nor metal leaching into the organic phase. Complex 3A also proved to be a general precatalyst for the carbonylative Sonogashira couplings of a wide range of aryl iodides with phenylacetylene. The selectivity of the desired carbonylation product depended more on electronic effects than the steric effects of the substituents of the aryl iodides.
研究领域:
有机化学
·
催化化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2016
·
IF 2.628
Da Yang,Dongliang Wang,Huan Liu,Xiaoli Zhao,Yong Lu,Shijun Lai,Ye Liu
The neutral palladium(II) complex bis-[1-(5’-diphenylphosphinothiazol-2’-yl)-imidazolyl] dichloropalladium(II) ( 1A ) ligated by thiazolylimidazolyl-based phosphine ( L1 ) in which thiazolylimidazolyl acted as an S- and N-donor provider with weak coordinating nature, and the ionic complex bis-[1-(5’-diphenylphosphinothiazol-2’-yl)-3-methylimidazolium] dichloropalladium(II) trifluoromethanesulfonate ( 2A ) ligated by thiazolylimidazolium-based phosphine ( L2 ) after quaternization of L1 using methyl trifluoromethanesulphonate were synthesized. It was found that the introduced positive charges and strong electron-withdrawing effect in 2A not only led to changes in the configuration and structural stability of the complex, but also lowered its catalytic performance in carbonylative Sonogashira reactions. These effects reveal the important role of the N-donor in 1A . In addition, as an ionic palladium complex, 2A combined with the room-temperature ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate could be recycled eight times as the catalyst in carbonylative Sonogashira reactions without detectable metal leaching.
研究领域:
有机化学
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催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2018
·Vol. 56
·期 20
·2344-2353
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IF 2.588
Jiajun Bi,Jian Chen,Yahao Dong,Wen Guo,Dajian Zhu,Tao Li
A new polymer was prepared from 1,3,5-triformylphloroglucinol (noted as TDTB) and o -phenylenediamine through Schiff base condensation reaction, and palladium (II) was immobilized on the polymer (noted as TbPo-Pd(II)). This process was easy to work-up and cost-effective. The structure and composition of TbPo-Pd(II) were fully characterized by FTIR, TGA, XPS, AAS, SEM, and TEM analyses. Meanwhile, this catalyst showed desired thermal stability and excellent performance in water/methanol system for Suzuki and Sonogashira coupling reactions. In addition, this heterogeneous catalyst can be readily recovered by simple filtration with no appreciable Pd leaching in the reaction. This work provides a powerful protocol for rapid access to asymmetrical biphenyls and aryl alkynes. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56 , 2344–2353
研究领域:
有机化学
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材料科学
✓ 已验证
DOI
高影响因子
CATALYSIS LETTERS
·
2016
·Vol. 146
·期 9
·1792-1799
·
IF 2.294
Wang Peng,Wang Guang-Yu,Qiao Wen-Long,Feng Yi-Si
Abstract In this study, palladium (0) nanoparticle supported on mesoporous carbon (Pd/MPC) is prepared by impregnation and H 2 reduction. Characterization by XRD, XPS and TEM reveals the mesoporous structure and a high dispersion of palladium nanoparticles (about 4.8 nm) in the mesopores. The catalyst has excellent catalytic activity and stability for Sonogashira reactions of aryl halide (–I, –Br) in aqueous solution. It is noteworthy that Sonogashira reactions of aryl halide (–Cl) can occur by using the novel Pd/MPC catalyst. Meanwhile, the catalyst can be recovered and reused without loss of efficiency until the fifth cycle in water. The fresh catalyst would be of major significance for industrial applications. Graphical Abstract
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 58
·30914-30922
·
IF 3.708
Mingxi Chen,Zhe Zhang,Lingzhi Li,Yu Liu,Wei Wang,Jianping Gao
Ultrafine Ag–Pd bimetallic nanoparticles homogeneously distributed on reduced graphene oxide (rGO) were prepared by redox reactions between Pd2+, Ag+ and GO. This method is simple, and the use of rGO as a support facilitated the separation and reuse of the Ag–Pd@rGO catalyst. The Ag–Pd@rGO bimetallic nanoparticles were characterized by ultraviolet-visible spectroscopy, Raman spectroscopy, thermogravimetric analysis, X-ray diffraction analysis, and X-ray photoelectron spectroscopy. The microstructure of the Ag–Pd@rGO was investigated with scanning electron microscopy and transmission electron microscopy. The Ag–Pd@rGO catalyst exhibited high catalytic activities in the Suzuki-Miyaura carbon coupling reaction and the Sonogashira carbon coupling (SCC) reaction. These reactions used mild, efficient, ligand-free and heterogeneous conditions. Interestingly, the presence or absence of oxygen in the SCC catalytic system resulted in two different products, in which oxygen can be used as “switch” to control different products.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）