7005-72-3Relevant articles and documents
Magnetization of graphene oxide nanosheets using nickel magnetic nanoparticles as a novel support for the fabrication of copper as a practical, selective, and reusable nanocatalyst in C-C and C-O coupling reactions
Hajjami, Maryam,Moradi, Parisa
, p. 25867 - 25879 (2021/08/09)
Catalyst species are an important class of materials in chemistry, industry, medicine, and biotechnology. Moreover, waste recycling is an important process in green chemistry and is economically efficient. Herein, magnetic graphene oxide was synthesized using nickel magnetic nanoparticles and further applied as a novel support for the fabrication of a copper catalyst. The catalytic activity of supported copper on magnetic graphene oxide (Cu-ninhydrin@GO-Ni MNPs) was investigated as a selective, practical, and reusable nanocatalyst in the synthesis of diaryl ethers and biphenyls. Some of the obtained products were identified by NMR spectroscopy. This nanocatalyst has been characterized by atomic absorption spectroscopy (AAS), scanning electron microscopy (SEM), wavelength dispersive X-ray spectroscopy (WDX), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and vibrating sample magnetometer (VSM) techniques. The results obtained from SEM shown that this catalyst has a nanosheet structure. Also, XRD and FT-IR analysis show that the structure of graphene oxide and nickel magnetic nanoparticles is stable during the modification of the nanoparticles and synthesis of the catalyst. The VSM curve of the catalyst shows that this catalyst can be recovered using an external magnet; therefore, it can be reused several times without a significant loss of its catalytic efficiency. The heterogeneity and stability of this nanocatalyst during organic reactions was confirmed by the hot filtration test and AAS technique.
Synergistic effect of copper nanocrystals-nanoparticles incorporated in a porous organic polymer for the Ullmann C-O coupling r–eaction
Gorginpour, Forough,Zali-Boeini, Hassan
, (2021/02/22)
A quinoxaline-based porous organic polymer (Q-POP) as a mesoporous organic copolymer was developed as a new platform for the immobilization of CuNPs and copper nanocrystals. The prepared materials were characterized by FT-IR, XRD, N2 adsorption-desorption isotherms, ICP, TGA, SEM, HR-TEM, EDX, and single-crystal X-ray crystallography. The obtained catalyst presented extraordinary catalytic activity towards Ullmann C–O coupling reactions with high surface area, hierarchical porosity, and excellent thermal and chemical stability. Due to its high porosity, and synergistic effect of copper nanocrystals incorporated in the polymer composite, the as-synthesized catalyst was successfully utilized for the Ullmann C–O coupling reaction of phenols and different aryl halides to prepare various diaryl ether derivatives. All types of aryl halides (except aryl fluorides) were screened in the Ullmann C–O coupling reaction with phenols to produce diaryl ethers in good to excellent yields (70–97 %), and it was found that aryl iodides have the best results. Besides, due to the strong interactions between CuNPs, N, and O-atoms of quinoxaline moiety existing in the polymeric framework, the copper leaching from the support was not observed. Furthermore, the catalyst was recycled and reused for five consecutive runs without significant activity loss.
Palladium complexes of chalcogenoethanamine (S/Se) bidentate ligands: Applications in catalytic arylation of C[sbnd]H and O[sbnd]H bonds
Bhatt, Ramprasad,Bhuvanesh, Nattamai,Himanshi,Joshi, Hemant,Sharma, Alpesh K.
, (2020/05/18)
This report describes the syntheses of N,E (E = S, Se) coordinated bidentate palladium complexes, by the reaction of N-(2-bromobenzyl)-2-(phenylthio/selanyl)ethanamine (3, 4) with [PdCl2(CH3CN)2]. The new ligands and palladium complexes were characterized by techniques like 1H, 13C{1H} NMR, IR, and elemental analysis. The coordination modes of ligand with palladium precursor in complexes 5 and 6 were authenticated by single crystal X-ray diffraction. The complexes possess distorted square planar geometry around palladium center. Thermally robust and air stable complexes 5 and 6 were used as catalyst for regioselective arylation of imidazole and O-arylation of phenol. In case of regioselective arylation of imidazole, the reaction proceeds smoothly under mild reaction conditions, only 2.0 mol% of catalyst loading is required to achieve high yield (76–92%). This protocol is applicable to a broad substrate scope showing excellent tolerance towards different functional groups. Whereas for O-arylation of phenol also only 2.0 mol% catalyst loading is sufficient to give good yield (71–92%) with excellent tolerance towards a broad range of functional groups. Among sulfur and selenium coordinated ligands, selenium ligand coordinated complex, was found to outperform the catalytic reactions in both cases as compare to sulfur ligand. The mercury and triphenylphosphine poisoning tests suggest homogeneous nature of catalysis.