scholarly journals Copper Immobilization on Fe3o4@Agar: An Efficient Superparamagnetic Nanocatalyst for Green Buchwald-Hartwig Cross-coupling Reaction of Primary and Secondary Amines With Aryl Iodide Derivatives

2021 ◽  
Author(s):  
Kimia Hoseinzade ◽  
Seyed Ali Mousavi-Mashhadi ◽  
Ali Shiri
Keyword(s):  
Electron Microscopy ◽  
Magnetic Nanoparticles ◽  
Inductively Coupled Plasma ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Secondary Amines ◽  
Aryl Iodide ◽  
X Ray ◽  
Inductively Coupled ◽  
Cross Coupling Reaction

Abstract Immobility of copper on magnetic nanoparticles was performed using surface rectification of Fe3O4 with Agar. The magnetic Fe3O4@Agar-Cu nanocatalyst was prepared and entirely characterized by different analyses such as Fourier transform infrared (FT‐IR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), energy dispersive X-ray (EDX), thermogravimetric (TGA), and inductively coupled plasma (ICP). The nanocatalyst was applied in C-N bond formation through the cross-coupling reaction of aryl halides with primary or secondary amines in water as a green medium known as the Buchwald-Hartwig reaction. The results of the Buchwald-Hartwig reaction by Fe3O4@Agar-Cu magnetic nanoparticles as catalyst demonstrate excellent activity and stability in water. Moreover, this catalyst can be recycled several times without considerable loss in its activity.

scholarly journals Pd Nanoparticles Stabilized on the Cross-Linked Melamine-Based SBA-15 as a Catalyst for the Mizoroki–Heck Reaction

2021 ◽  
Author(s):  
Ayat Nuri ◽  
Abolfazl Bezaatpour ◽  
Mandana Amiri ◽  
Nemanja Vucetic ◽  
Jyri-Pekka Mikkola ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
High Surface ◽  
High Surface Area ◽  
Coupling Reaction ◽  
Pd Nanoparticles ◽  
Significant Activity ◽  
Inductively Coupled ◽  
Transmission Electron ◽  
Ft Ir

AbstractMesoporous SBA-15 silicate with a high surface area was prepared by a hydrothermal method, successively modified by organic melamine ligands and then used for deposition of Pd nanoparticles onto it. The synthesized materials were characterized with infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), nitrogen physisorption, scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) and inductively coupled plasma (ICP-OES). The catalyst was effectively used in the Mizoroki–Heck coupling reaction of various reactants in the presence of an organic base giving the desired products in a short reaction time and with small catalysts loadings. The reaction parameters such as the base type, amounts of catalyst, solvents, and the temperature were optimized. The catalyst was easily recovered and reused at least seven times without significant activity losses. Graphic Abstract

scholarly journals Efflorescent Sulfate Crystallization on Fractured and Polished Colloform Pyrite Surfaces: A Migration Pathway of Trace Elements

Minerals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 12
Author(s):  
Dimitrina Dimitrova ◽  
Vassilka Mladenova ◽  
Lutz Hecht
Keyword(s):  
Electron Microscopy ◽  
Trace Elements ◽  
Inductively Coupled Plasma ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
X Ray ◽  
Inductively Coupled ◽  
Migration Pathway ◽  
Plasma Mass Spectrometry ◽  
Scanning Electron

The colloform pyrite variety incorporates many trace elements that are released in the environment during rapid oxidation. Colloform pyrite from the Chiprovtsi silver–lead deposit in Bulgaria and its oxidation efflorescent products were studied using X-ray diffractometry, scanning electron microscopy, electron microprobe analysis, and laser ablation inductively coupled plasma mass spectrometry. Pyrite is enriched with (in ppm): Co (0.1–964), Ni (1.8–3858), Cu (2.9–3188), Zn (3.1–77), Ag (1.2–1771), As (8179–52,787), Se (2.7–21.7), Sb (48–17792), Hg (4–2854), Tl (1.7–2336), Pb (13–7072), and Au (0.07–2.77). Gypsum, anhydrite, szomolnokite, halotrichite, römerite, copiapite, aluminocopiapite, magnesiocopiapite, coquimbite, aluminocoquimbite, voltaite, and ammoniomagnesiovoltaite were identified in the efflorescent sulfate assemblage. Sulfate minerals contain not only inherited elements from pyrite (Cr, Fe, Co, Ni, Cu, Zn, Ag, In, As, Sb, Hg, Tl, and Pb), but also newly introduced elements (Na, Mg, Al, Si, P, K, Ca, Sc, Ti, V, Mn, Ga, Rb, Sr, Y, Zr, Sn, Cs, Ba, REE, U, and Th). Voltaite group minerals, copiapite, magnesiocopiapite, and römerite incorporate most of the trace elements, especially the most hazardous As, Sb, Hg, and Tl. Colloform pyrite occurrence in the Chiprovtsi deposit is limited. Its association with marbles would further restrict the oxidation and release of hazardous elements into the environment.

Photocatalytic Oxidation of Alcohols Over Magnetically Recoverable Gold Supported Iron Oxide Nanoparticles

2019 ◽  
Vol 11 (12) ◽  
pp. 1731-1738 ◽  
Author(s):  
Ma Hui ◽  
Wu Juzhen ◽  
Zhao Li ◽  
Zhou Zheng ◽  
Guo Jiahu
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Photocatalytic Oxidation ◽  
Organic Dyes ◽  
Atomic Emission ◽  
One Pot ◽  
X Ray ◽  
Inductively Coupled ◽  
Oxidation Of Alcohols

A one-pot simple and efficient synthetic route for the synthesis of Au-loaded Fe2O3 nanoparticles was developed, and this material's photocatalytic activity for visible light assisted oxidation of alcohols and degradation of organic dye were studied. As-synthesized nanostructured catalyst was characterised by powder X-ray diffraction (XRD), transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), SEM-mapping, X-ray photoelectron spectroscopy (XPS), N2 adsorption–desorption isotherm (BET), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). It was observed that 5–10 nm Au-nanoparticles supported on 10–80 nm Fe2O3 shows boomerang-shaped nanoparticle. Gold loading of 1 wt% shows high conversion and selectivity towards the target product aldehyde. The synthesized nanomaterial also proved to be an excellent photocatalyst for degradation of organic dyes such as methylene blue (MB) and rhodamine B (RhB). The catalyst proved to be noteworthy as it does not loss in its catalytic activity even after five cycles of reuse.

Synthesis of 4,4-Difluoro-a-tocopherol Using a Cross-coupling Reaction of Bromodifluoroacetate with Aryl Iodide in the Presence of Copper Powder

Heterocycles ◽  
2002 ◽  
Vol 56 (1-2) ◽  
pp. 403 ◽  
Author(s):  
Itsumaro Kumadaki ◽  
Kazuyuki Sato ◽  
Takashi Nishimoto ◽  
Kei Tamoto ◽  
Masaaki Omote ◽  
...  
Keyword(s):  
Copper Powder ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Aryl Iodide ◽  
Cross Coupling Reaction

scholarly journals Acetalization of Glycerol with Citral over Heteropolyacids Immobilized on KIT-6

Catalysts ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 81
Author(s):  
José Castanheiro
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
Fixed Time ◽  
Tungstophosphoric Acid ◽  
X Ray Diffraction ◽  
Glycerol Conversion ◽  
X Ray ◽  
Inductively Coupled ◽  
Catalytic Stability ◽  
Scanning Electron

Glycerol acetalization with citral was studied using a heteropolyacid (tungstophosphoric acid) supported on KIT-6, as a catalyst, at 100 °C. Different catalysts were synthesized. Catalysts were characterized by scanning electron microscopy (SEM), inductively coupled plasma (ICP), X-ray diffraction (XRD), attenuated total refletion-Fourier transform infrared spectroscopy (ATR-FTIR), and potentiometric titrations. At a fixed time, the glycerol conversion increased with the H3PW12O40 (PW) on KIT-6. PW4-KIT-6 material had a higher conversion than other catalysts. The optimization of glycerol’s acetalization with citral was studied under the PW4-KIT-6 catalyst. After 5 h, it was found that, at T = 100 °C, with m = 0.3 g of solid, molar glycerol:citral = 1:2.25, the conversion of glycerol was 89%. Moreover, the PW4-KTI-6 catalyst showed good catalytic stability.

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