939-97-9Relevant articles and documents
Preparation, characterization and catalytic performance of bimetallic Ti-Co-MCM-41 catalysts
Zhang, Jinfeng,Zhang, Jiyao,Zhao, Jianshe,Zhang, Cunshe,Shen, Hanxi,Zhou, Kui
, p. 273 - 276 (2015)
Ti-Co-MCM-41 molecular sieve catalysts were synthesized using the impregnation method. The catalysts were characterized by X-ray diffraction, UV-visible, Fourier transform infrared spectroscopy and low temperature N2 adsorption-desorption. Their performance in 4-tert-butylbenzaldehyde synthesis was evaluated in mild conditions by oxygen oxidation 4-tert-butyltoluene. The results showed that the catalysts had large surface area and pore size and contained titanium and cobalt with four ligands, which formed the catalysts of high catalytic activity. The conversion rate of 4-tert-butyl toluene was improved by 38%, the selectivity of 4-tert-butyl benzaldehyde was improved by 85% and the yield of 4-tert-butyl benzaldehyde was up to 35%.
Selective oxidation of benzylic alcohols with molecular oxygen catalyzed by copper-manganese oxide nanoparticles
Ali, Roushown,Assal,Al-Warthan, Abdulrahman,Rafiq,Siddiqui
, p. 4815 - 4819 (2013)
The catalytic activity of copper-manganese (CuMn) mixed oxide nanoparticles (Cu/Mn = 1:1) prepared by co-precipitation method has been studied for the selective oxidation of benzyl alcohol and its derivatives to the corresponding aldehydes using molecular
Efficient catalysis of a redox reaction by an artificial enzyme
Ye, Hongping,Tong, Weida,D'Souza, Valerian T.
, p. 5470 - 5472 (1992)
-
Inhibition of the Cobalt Acetate/Bromide-Catalyzed Hydrogen Peroxide Oxidation of 4-tert-Butyltoluene
Amin, Ahmed A.,Beattie, James K.
, p. 879 - 882 (2003)
The hydrogen peroxide oxidation of 4-tert-butyltoluene to 4-tert-butylbenzaldhyde, an important fragrance intermediate, catalyzed by cobalt acetate and bromide in acetic acid was investigated again. The initial stages of the reaction appear to be rapid and quantitative, but after approximately 25-30% conversion, the process ceases. Overoxidation to 4-tert-butylbenzoic acid does not occur. It appears that both water and the aldehyde product itself inhibit further oxidation. An engineering solution to remove the product continuously seems required for process optimization.
Functionalized-1,3,4-oxadiazole ligands for the ruthenium-catalyzed Lemieux-Johnson type oxidation of olefins and alkynes in water
Hkiri, Shaima,Touil, Soufiane,Samarat, Ali,Sémeril, David
, (2021/11/30)
Three arene-ruthenium(II) complexes bearing alkyloxy(5-phenyl-1,3,4-oxadiazol-2-ylamino)(4-trifluoromethylphenyl)methyl ligands were quantitatively obtained through the reaction of (E)-1-(4-trifluoromethylphenyl)-N-(5-phenyl-1,3,4-oxadiazol-2-yl)-methanimine with the ruthenium precursor [RuCl2(η6-p-cymene)]2 in a mixture of the corresponding alcohol and CH2Cl2 at 50 °C. The obtained complexes were fully characterized by elemental analysis, infrared, NMR and mass spectrometry. Solid-state structures confirmed the coordination of the 1,3,4-oxadiazole moiety to the ruthenium center via their electronically enriched nitrogen atom at position 3 in the aromatic ring. These complexes were evaluated as precatalysts in the Lemieux-Johnson type oxidative cleavage of olefins and alkynes in water at room temperature with NaIO4 as oxidizing agent. Good to full conversions of olefins into the corresponding aldehydes were measured, but low catalytic activity was observed in the case of alkynes. In order to get more insight into the mechanism, three analogue arene-ruthenium complexes were synthesized and tested in the oxidative cleavage of styrene. The latter tests clearly demonstrated the importance of the hemilabile alkyloxy groups, which may form more stable (N,O)-chelate intermediates and increase the efficiency of the cis-dioxo-ruthenium(VI) catalyst.
Aerobic epoxidation of styrene over Zr-based metal-organic framework encapsulated transition metal substituted phosphomolybdic acid
Hu, Dianwen,Song, Xiaojing,Zhang, Hao,Chang, Xinyu,Zhao, Chen,Jia, Mingjun
, (2021/04/19)
Catalytic epoxidation of styrene with molecular oxygen is regarded as an eco-friendly alternative to producing industrially important chemical of styrene oxide (STO). Recent efforts have been focused on developing highly active and stable heterogeneous catalysts with high STO selectivity for the aerobic epoxidation of styrene. Herein, a series of transition metal monosubstituted heteropolyacid compounds (TM-HPAs), such as Fe, Co, Ni or Cu-monosubstituted HPA, were encapsulated in UiO-66 frameworks (denoted as TM-HPA@UiO-66) by direct solvothermal method, and their catalytic properties were investigated for the aerobic epoxidation of styrene with aldehydes as co-reductants. Among them, Co-HPA@UiO-66 showed relatively high catalytic activity, stability and epoxidation selectivity at very mild conditions (313 K, ambient pressure), that can achieve 82 % selectivity to STO under a styrene conversion of 96 % with air as oxidant and pivalaldehyde (PIA) as co-reductant. In addition, the hybrid composite catalyst can also efficiently catalyze the aerobic epoxidation of a variety of styrene derivatives. The monosubstituted Co atoms in Co-HPA@UiO-66 are the main active sites for the aerobic epoxidation of styrene with O2/PIA, which can efficiently converting styrene to the corresponding epoxide through the activation of the in-situ generated acylperoxy radical intermediate.