936013-82-0Relevant academic research and scientific papers
N-heterocyclic carbene Pd(II) complex supported on Fe3O4@SiO2: Highly active, reusable and magnetically separable catalyst for Suzuki-Miyaura cross-coupling reactions in aqueous media
Akko?, Mitat,Bu?day, Nesrin,Alt?n, Serdar,Kiraz, Nadir,Ya?ar, Sedat,?zdemir, ?smail
, (2021)
A new type magnetic nano Fe3O4@SiO2@NHC@Pd-MNPs heterogeneous catalyst was fabricated and characterized by Fourier Transform Infrared (FTIR) spectroscopy, Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Energy Disperse X-ray analysis (EDX), Thermogravimetric Analysis (TGA), Differential Thermal Analysis (DTA), and Scanning Electron Microscopy (SEM). The loading amount of Palladium (Pd) to magnetic nano Fe3O4@SiO2@NHC@Pd-MNPs was measured by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) analysis. The catalytic activity of magnetic nano Fe3O4@SiO2@NHC@Pd-MNPs heterogeneous catalyst was examined on Suzuki-Miyaura cross-coupling reactions of aryl halides with different substituted arylboronic acid derivatives. All coupling reactions yielded excellent results and high TOF (up to 76528 h?1) in the presence of 2 mg of Fe3O4@SiO2@NHC@Pd-MNPs catalyst (0.0197 mmolg?1, 0.00394 mmol%Pd) at 80 °C in 2-propanol/H2O (1:2). In addition, the magnetic nano Fe3O4@SiO2@NHC@Pd-MNPs catalyst was easily recovered by using an external Nd-magnet and reused for the Suzuki cross-coupling reactions. The catalyst showed strong structural and chemical stability and was reused six times without losing its catalytic activity substantially.
Magnetite@MCM-41 nanoparticles as support material for Pd-N-heterocyclic carbene complex: A magnetically separable catalyst for Suzuki–Miyaura reaction
Akko?, Mitat,Bu?day, Nesrin,Alt?n, Serdar,Ya?ar, Sedat
, (2021/03/22)
The Magnetite@MCM-41@NHC@Pd catalyst was obtained with Pd metal bound to the NHC ligand anchored to the surface of Fe3O4@MCM-41. It was characterized by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy disperse X-ray analysis (EDX), thermogravimetric analysis (TGA), differential thermal analysis (DTA), and scanning electron microscopy (SEM). The amount of Pd in the Magnetite@MCM-41@NHC@Pd was measure by inductively coupled plasma–optical emission spectroscopy (ICP-OES) analysis. The catalytic activity of Magnetite@MCM-41@NHC@Pd heterogeneous catalyst done on Suzuki–Miyaura reactions of aryl halides with different substituted arylboronic acid derivatives. All coupling reactions afforded excellent yields and up to 408404 Turnover Frequency (TOF) h?1 in the presence of 2 mg of Magnetite@MCM-41@NHC@Pd catalyst (0.0564 mmol g?1, 0.01127 mmol% Pd) at room temperature in 2-propanol/H2O (1:2). Moreover, Magnetite@MCM-41@NHC@Pd catalyst was recover by applying the magnet and reused for another reaction. The catalyst showed excellent structural and chemical stability and reused ten times without a substantial loss in its catalytic performance.
Syntheses of Pyrroles, Pyridines, and Ketonitriles via Catalytic Carbopalladation of Dinitriles
Qi, Linjun,Li, Renhao,Yao, Xinrong,Zhen, Qianqian,Ye, Pengqing,Shao, Yinlin,Chen, Jiuxi
, p. 1097 - 1108 (2020/01/22)
The first example of the Pd-catalyzed addition of organoboron reagents to dinitriles, as an efficient means of preparing 2,5-diarylpyrroles and 2,6-diarylpyridines, has been discussed here. Furthermore, the highly selective carbopalladation of dinitriles with organoboron reagents to give long-chain ketonitriles has been developed as well. Based on the broad scope of substrates, excellent functional group tolerance, and use of commercially available substrates, the Pd-catalyzed addition reaction of arylboronic acid and dinitriles is expected to be significant in future synthetic procedures.
A Heterobimetallic AuIII-PtII Photocatalyst for Water Reduction to Hydrogen
Su, Yi-Bing,Yuan, Yong-Jun,Liu, Xiao-Le,Chen, Guang-Hui,Chen, Xin,Yu, Zhen-Tao,Zou, Zhi-Gang
supporting information, p. 527 - 531 (2019/01/29)
A supramolecular complex, [Au(C^N^C)(C≡CC6H4C≡C)Pt(terpy)]+, has been synthesized as a photocatalyst for water reduction. This compound consists of a cyclometalated alkyne-gold(III) photosensitizer and a platinum(II) terpyridine complex bridged through a central phenylethynyl group.
Direct C-H Functionalization of Pyridine via a Transient Activator Strategy: Synthesis of 2,6-Diarylpyridines
Zeng, Yang,Zhang, Chunchun,Yin, Changzhen,Sun, Maoshen,Fu, Haiyan,Zheng, Xueli,Yuan, Maolin,Li, Ruixiang,Chen, Hua
supporting information, p. 1970 - 1973 (2017/04/27)
A Pd-catalyzed highly selective direct diarylation of pyridines has been developed using a transient activator strategy. Both (MeO)2SO2 and Cu2O are required for this transformation. The in situ generated N-methylpyridinium salt can be arylated at both 2- and 6-positions under the cooperative Pd/Cu catalysis. A subsequent N-demethylation then gives the 2,6-diarylpyridines. This protocol provides a novel synthetic route for the symmetric 2,6-diarylpyridines.
Method for double carbon-hydrogen activation and arylation of pyridine compounds
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Paragraph 0040; 0041; 0042; 0043; 0044; 0049-0052, (2017/04/21)
The invention discloses a method for double carbon-hydrogen activation and arylation of pyridine compounds, and belongs to the field of methodology of organic synthesis. The method comprises the following steps: mixing a palladium source, a phosphine ligand, a copper salt or an oxide of copper, an alkali and aryl halide, placing the mixture in a nitrogen gas environment, then adding an additive, 4-substituted pyridine and a solvent, and carrying out a heating reaction, to obtain a C2-site and C6-site double aryl substituted pyridine compounds through a carbon-hydrogen activation mechanism, wherein a substituent group of 4-substituted pyridine is any one of hydrogen, alkyl and aryl. The method has the advantages of wide application range, simple operation steps, no need of pre-activation of a pyridine ring, and no need of introduction of a guiding group, and extremely high atomic economy and practicability.
Evaluation of bis-cyclometalated alkynylgold(III) sensitizers for water photoreduction to hydrogen
Yu, Zhen-Tao,Liu, Xiao-Le,Yuan, Yong-Jun,Li, Yong-Hui,Chen, Guang-Hui,Zou, Zhi-Gang
supporting information, p. 17223 - 17232 (2016/11/13)
Well-defined gold sensitizers for hydrogen production from water remain extremely rare despite decades of interest, and are currently limited to systems based on ruthenium, iridium or platinum complexes. This report details the synthesis and characterization of a series of neutral cyclometalated gold(iii) complexes of the type [(RC^N^CR)Au(CC-R′)] (R = H or tert-butyl group; R′ = aryl groups) that have been found to be good candidates to function as harvesting materials in light-induced electron transfer reactions. We established the efficacy of systems with these gold(iii) complexes as photosensitizers (PSs) in the production of renewable hydrogen in the presence of [Co(2,2′-bipyridine)3]Cl2 or [Rh(4,4′-di-tert-butyl-2,2′-bipyridine)3](PF6)3 as a H2-evolved catalyst and triethanolamine (TEOA) as a sacrificial electron donor in acetone-water solution. All complexes are active, and there is a more than threefold increase over other candidates in photocatalytic H2 generation activity. Under the optimal reaction conditions, hydrogen evolution took place through a photochemical route with the highest efficiency and with a turnover number (TON) of up to 1441.5 relative to the sensitizer over 24 hours. In the initial photochemical path, the reductive quenching of the excited gold(iii) complex by TEOA due to the latter's greater concentration in the system followed by electron transfer to the catalyst species is proposed to be the dominant mechanism. A photo-to-H2 quantum yield of approximately 13.7% was attained when illuminated with monochromatic light of 400 nm. Such gold(iii) complexes have demonstrated significant utility in solar-to-hydrogen reactions and thus represent a new effective class of light-harvesting materials. These results open possibilities for pursuing more efficient photosensitizers featuring gold(iii) complexes in photocatalytic solar energy conversion.
One-pot synthesis of symmetrical 2,6-diarylpyridines via palladium/copper-catalyzed sequential decarboxylative and direct C-H arylation
Ma, Zhiyong,Liu, Hailong,Zhang, Chunchun,Zheng, Xueli,Yuan, Maolian,Fu, Haiyan,Li, Ruixiang,Chen, Hua
supporting information, p. 1143 - 1148 (2015/04/22)
A palladium(II)/copper oxide (Cu2O)-catalyzed one-pot decarboxylative and direct C-H arylation of 2-picolinic acid with aryl bromides has been developed. Various aryl bromides have been shown to be efficient coupling partners in the presence of dimethyl sulfate, furnishing symmetrical 2,6-diarylpyridines in moderate to good yields.
