scholarly journals Synthesis and application of SBA-15-supported CuO as an efficient catalyst for the oxidative C(sp2)-O coupling reaction

2021 ◽  
Vol 947 (1) ◽  
pp. 012033
Author(s):  
Ha V. Le ◽  
Khanh V. Ho ◽  
Tu T. Le ◽  
Vy T.B. Nguyen ◽  
Huy X. Le ◽  
...  

Abstract SBA-15-supported CuO was synthesized via wet impregnation of SBA-15 with copper (II) acetylacetonate followed by calcination in the static air. The BET surface area of the Cu-containing SBA-15 was approximately 600 m2/g, which significantly decreased in comparison with that of as-synthesized SBA-15 silica (1081 m2/g). The successful loading of copper with a 3.20 wt.% content was determined by ICP-OES analysis, consistent with theoretical composition. However, no Cu-based phases were detected on the PXRD results and TEM images for CuO/SBA-15 showed regular hexagonal meso channels remained, indicating that CuO species was well distributed in the SBA-15 framework via the applied synthetic procedure. Catalytic activity of SBA-15-supported CuO was investigated for the selective C(sp2)-O coupling reaction between salicylaldehyde and N, N-dimethylformamide (DMF) in the presence of di-tert butyl peroxide (DTBP) as an oxidant. Influence of the reaction conditions on the formation of desired product was studied including reaction time, temperature, reactant ratio, amount of catalyst and oxidant. The experimental results proved that the high activity of the prepared catalyst as the C(sp2)-O coupling product could be obtained in an excellent yield of 90% with only 3 mol% of SBA-15-supported CuO in the presence of 4 equivalents of DTBP at 120 °C in 2 hours.

RSC Advances ◽  
2014 ◽  
Vol 4 (69) ◽  
pp. 36437-36443 ◽  
Author(s):  
Zhenhong Guan ◽  
Buyi Li ◽  
Guoliang Hai ◽  
Xinjia Yang ◽  
Tao Li ◽  
...  

Microporous polymers with built-in triphenylphosphine palladium exhibit highly efficient catalytic activity for cross-coupling reactions of benzyl chloride under mild conditions.


2012 ◽  
Vol 11 (2) ◽  
pp. 1-16
Author(s):  
Sreejarani K Pillai ◽  
O Gheevarghese ◽  
I V Tleane

The present study has undertaken the Friedel-Crafts benzylation of aromatics over the V2O5/ZrO2 catalysts systems. Catalysts with different V2O5 content (0-15wt %) was prepared by wet impregnation method and characterized by XRD, BET surface area, FTIR and 5’V NMR techniques. The surface acidic properties were determined by temperature programmed desorption of NH3, cumene cracking and perylene adsorption. Under the optimized reaction conditions, these catalysts are found to be very effective and considerably more selective than the conventional homogeneous Lewis acid catalysts. The investigation of vanadia systems-catalyzed benzylation of o-xylene with benzyl chloride revealed that the catalytic activity and product selectivity are sensitive to the precise reaction parameters and can be related to the Lewis acidity of the systems. The reaction is found to be very clean and produces the desired monoalkylated product with high yield.


2021 ◽  
Author(s):  
Samahe Sadjadi ◽  
Neda Abedian-Dehaghani ◽  
Majid M. Heravi

Abstract In this work, an ionic liquid-containing thermo-responsive heterogeneous catalyst with utility for promoting hydrogenation of nitro-compounds in aqueous media is developed. To prepare the catalyst, silica-coated carbon nanotubes were synthesized and vinyl-functionalized. The resulted compound was then polymerized with 1-viny-3-butylimidazolium bromide and N-isopropylacrylamide. The obtained ionic liquid-containing thermo-responsive composite was palladated via wet-impregnation method to give the final catalyst. Study of the performance of the catalyst confirmed high catalytic activity of the catalyst at temperature above the lower critical solution temperature. Furthermore, the catalyst was highly recyclable and showed negligible Pd leaching upon recycling. Broad substrate scope and selectivity of the catalyst towards reduction of nitro functionality were also confirmed. Furthermore, hot filtration test implied the heterogeneous nature of the catalysis. The comparison of the activity of Pd/CNT-P with some control catalysts approved the importance of hybridization of P and CNT and the presence of ionic liquid for the catalytic activity.


Author(s):  
Siti Kamilah Che Soh ◽  
Mustaffa Shamsuddin

Mizoroki-Heck cross-coupling reaction of 4-bromoacetophenone with methyl acrylate were investigated as a model system of heterogeneous reaction in order to evaluate the performance of polyaniline supported N,N’-bis(3,5-di-tert-butylsalicylidene)propane-1,3-diaminepalladium(II) complex as catalyst. The reactions were carried out in both N,N-dimethylacetamide (DMAc) and water-DMAc mixed solvent. The performances of the catalyst in both media are comparable, giving more than 90 % conversion after 24 hours of reaction with 100 % selectivity and high isolated product yields of cinnamic esters were obtained. The used of mixed solvent gave more advantages such as less organic solvent was required and an enhanced recyclability in which the supported catalyst could be reusable at least four times without noticeable decrease in the product conversion. The properties of the catalyst was characterized by various techniques such as FTIR spectroscopy, TG-DTA, AAS, BET surface area, XRD and FESEM.


2021 ◽  
Vol 11 (11) ◽  
pp. 4822
Author(s):  
Hamed M. Alshammari ◽  
Obaid F. Aldosari ◽  
Mohammad Hayal Alotaibi ◽  
Raja L. Alotaibi ◽  
Mosaed S. Alhumaimess ◽  
...  

Palladium-based carbon catalysts (Pd/C) can be potentially applied as an efficient catalyst for Suzuki–Miyaura and Mizoroki–Heck coupling reactions. Herein, a variety of catalysts of palladium on activated carbon were prepared by varying the content of ‘Pd’ via an in situ reduction method, using hydrogen as a reducing agent. The as-prepared catalysts (0.5 wt % Pd/C, 1 wt % Pd/C, 2 wt % Pd/C and 3 wt % Pd/C) were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and Brunauer–Emmett–Teller (BET) analyses. The catalysts were tested as a coupling catalyst for Suzuki–Miyaura coupling reactions involving aryl halides and phenyl boronic acid. The optimization of the catalyst by varying the palladium content on the activated carbon yielded Pd/C catalysts with very high catalytic activity for Suzuki reactions of aryl halides and a Mizoroki–Heck cross-coupling reaction of 4-bromoanisol and acrylic acid in an aqueous medium. A high ‘Pd’ content and uniform ‘Pd’ impregnation significantly affected the activity of the catalysts. The catalytic activity of 3% Pd/C was found to make it a more efficient catalyst when compared with the other synthesized Pd/C catalysts. Furthermore, the catalyst reusability was also tested for Suzuki reactions by repeatedly performing the same reaction using the recovered catalyst. The 3% Pd/C catalyst displayed better reusability even after several reactions.


2013 ◽  
Vol 67 (2) ◽  
Author(s):  
Belladamadu Anandakumar ◽  
Muthukur Madhusudana Reddy ◽  
Kumarappa Thipperudraiah ◽  
Mohamed Pasha ◽  
Gujjarahalli Chandrappa

AbstractA simple and rapid synthesis of CdO nanopowder via the solution combustion route employing l-(+)-tartaric acid as a fuel is reported for the first time. The catalyst was characterized by PXRD, SEM, TEM, BET surface area measurement, basic site measurement from back titration and FTIR. Combustion derived CdO nanopowder acts as a catalyst in the sulfonylation of amines with p-toluenesulfonyl chloride to obtain sulfonamides in excellent yield (85–95 %) and high purity under mild reaction conditions. CdO nanopowder has been found to be an efficient catalyst requiring a shorter reaction time (10–30 min) to obtain sulfonamide when compared with the commercial CdO powder requiring 2 h under similar conditions. The catalyst can be recovered and reused four times without any significant loss of catalytic activity. Potential role of CdO nanopowder in the synthesis of sulfonamides and its mechanism is proposed.


RSC Advances ◽  
2016 ◽  
Vol 6 (61) ◽  
pp. 56028-56034 ◽  
Author(s):  
Li Wu ◽  
Bin Yuan ◽  
Mengmeng Liu ◽  
Hongfei Huo ◽  
Yu Long ◽  
...  

A Pd0/Fe3O4-DA/DMG catalyst exhibited excellent catalytic activity toward the Suzuki, Heck and Kumada cross coupling reaction with a high yield. It is an especially efficient catalyst for Suzuki and Heck coupling in water.


2011 ◽  
Vol 233-235 ◽  
pp. 188-193 ◽  
Author(s):  
Hai Bing Yu ◽  
Jun Nan ◽  
Jing Cheng Zhang ◽  
Jian Zhou Gui

Alkylation of phenol with cyclohexanol catalyzed by acidic ionic liquid has been investigated. The influences of reaction temperature, reaction time, reactant ratio (mol ratio of phenol to cyclohexanol), the amount and the recycle of ionic liquid on catalytic activity were studied. The conversion of phenol and the selectivity of paracyclohexylphenol were 75.5% and 61.6%, respectively, under optimum reaction conditions. The ionic liquid was utilized repeatedly over three times without remarkable loss of catalytic activity.


2018 ◽  
Vol 36 (5-6) ◽  
pp. 1352-1365 ◽  
Author(s):  
Hany A Elazab ◽  
M.A. Sadek ◽  
Tamer T El-Idreesy

We report here a reliable green method for the synthesis of palladium nanoparticles supported on copper oxide as a highly active and efficient catalyst for Suzuki cross-coupling reaction. The experimental synthetic approach is based on microwave-assisted chemical reduction of an aqueous mixture of palladium and copper salt simultaneously using hydrazine hydrate as reducing agent. The catalyst was fully characterized using various techniques showing well-dispersed palladium nanoparticles. The catalytic activity and recyclability of the prepared catalyst were experimentally explored in the ligand-free Suzuki cross-coupling reaction with a diverse series of functionalized substrates. The synthesized Pd/CuO catalyst shows many advantages beside its high catalytic efficiency such as the recyclability of up to five times with negligible loss of catalytic activity, short reaction times, use of environmentally benign solvent systems, and mild reaction conditions.


2015 ◽  
Vol 1089 ◽  
pp. 133-136 ◽  
Author(s):  
Zhi Dan Fu ◽  
Qing Ye ◽  
Shui Yuan Cheng ◽  
Dao Wang

The manganese oxide (MnO2) sample was synthesized by the reaction of KMnO4 with Mn (Ac)2 using the HNO3 solution as pH regulator. The Ag-doped manganese oxide, Ag/MnO2-Q and Ag/MnO2-H, were synthesized by incorporation method and typical wet impregnation method, respectively. The structure of catalysts was characterized by N2 adsorption/desorption and X-ray diffraction. The influences of preparation methods on the catalytic activity of CO oxidation were studied. The doping of Ag to MnO2 decreased the specific surface area of Ag/MnO2 catalysts, especially for Ag/MnO2-H samples prepared by traditional wet-impregnation method. The Ag/MnO2 catalysts showed higher catalytic activity for CO oxidation than that of MnO2. The catalytic activities of Ag/MnO2 samples strongly depended upon the preparing methods, among which 3Ag/MnO2-Q catalyst, prepared by the incorporation method, was the most efficient catalyst towards the addressed reactions. The excellent performance of 3Ag/MnO2-Q was mainly associated with the good low-temperature reducibility, abundant surface oxygen and broadly dispersed silver oxides species.


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