611-94-9Relevant articles and documents
Fe Doped MIL-101/Graphene Nanohybrid for Photocatalytic Oxidation of Alcohols Under Visible-Light Irradiation
Wang, Mingming,Ma, Yali,Lv, Bolin,Hua, Fenglin,Meng, Shuangyan,Lei, Xuedi,Wang, Qingtao,Su, Bitao,Lei, Ziqiang,Yang, Zhiwang
, p. 2384 - 2395 (2021)
A novel photoactive porous material of GR/FeMIL-101 based on FeMIL-101 metal organic frameworks (MOFs) was successfully synthesized via a simple hydrothermal method. The structural and photoelectric properties of the GR/FeMIL-101 was analyzed by XRD, SEM, TEM, TGA, XPS, UV–vis DRS, FT-IR, PL and EIS methods. The photocatalytic performance for the selective oxidation of benzyl alcohol with GR/FeMIL-101 as catalysts was evaluated under visible light irradiation. The results showed that the GR/FeMIL-101 nanohybrid had better photocatalytic performance than both of FeMIL-101 and the pristine MIL-101. It was further found that the incorporation of Fe and MIL-101 caused valence fluctuations of Fe3+/Fe2+ which improved the absorption of visible-light and increased the separation efficiency of photogenerated charges. In addition, the combination of FeMIL-101 and GR could further promote the transfer rate of the photoelectrons. The mechanism of the reaction revealed that ·O2? was the dominating active specie in this reaction through active species trapping experiments. Graphic Abstract: [Figure not available: see fulltext.]Fe doped MIL-101/GR nanohybrid was successfully synthesized as an efficient photocatalyst for selective oxidation of alcohols under visible-light and shown a best conversion of 50%. Analyses revealed that Fe was successfully doped into the MIL-101, valence fluctuation of Fe2+/Fe3+ not only improved the visible-light absorption but also increased the separation rate of photoexcited carriers. Graphene further improved the transportation rate of electron (e-). Subsequently, the possible photocatalytic mechanism for the selective oxidation of alcohols was proposed. It was proved that superoxide radicals (·O2-) was the main active species when the reaction was performed under Oxygen atmosphere.
Friedel-crafts benzoylation of anisole in ionic liquids: Catalysis, separation, and recycle studies
Hardacre, Christopher,Nancarrow, Paul,Rooney, David W.,Thompson, Julian M.
, p. 1156 - 1163 (2008)
The comparison of three ionic liquid-mediated catalytic processes for the benzoylation of anisole with benzoic anhydride is presented. A detailed understanding of the mechanism by which the zeolite and metal triflate reactions in bis{trifluoromethanesulfonyl}imidebased ionic liquids has been reported previously, and these routes are considered together with an indium chloride-based ionic liquid system. Solvent extraction and vacuum/steam distillation have been assessed as possible workup procedures, and an overall preliminary economic evaluation of each overall process is reported. Although the predominant activity is associated with the in situ formation of a homogeneous acid catalyst, the low cost and facile separation of the zeolite-catalysed process leads to this route being the most economically viable overall option. The results of a continuous flow miniplant based on the zeolite catalyst are also presented and compared with the reaction using a small plug flow reactor.
Mechanism of the Superoxide Anion Radical (O2-) Mediated Oxidation of Diarylmethanes
Frimer, Aryeh A.,Farkash-Solomon, Tova,Aljadeff, Gladis
, p. 2093 - 2098 (1986)
Variously substituted diphenylmethanes (2a-l) were prepared and reacted competitively with O2- (generated from KO2/18-crown-6 polyether) in benzene.The relative rate constants (krel) correlated best (r = 0.993) with ?-, giving a ρ value of 3.96 +/- 0.16.For the corresponding oxygenation mediated by tert-butoxide, the ρ obtained was 1.77 +/- 0.41 (r = 0.950).The primary deuterium isotope effects (kH/kD) on the superoxide reaction of diphenylmethane and its 4,4'-dichloro analogue were 2.36 and 2.14, respectively.The rate of reaction was found to be line arly proportional to the crown ether concentration, and no reaction occurred in its absence.These results indicate that the reaction is homogeneous and is first order in superoxide and diphenylmethane.The correlation with ?- and the magnitudes of ρ and the primary isotope effect are interpreted as requiring a reaction sequence in which a proton is first transfered from substrate to superoxide in the rate-determining step, with the resulting benzylic anion undergoing subsequent oxygenation to the corresponding ketones 1.A Broensted analysis of the deprotonation reaction yields an α value of 0.69, suggesting a late transition state.The discrepancy between these results obtained in benzene and those of others for Me2SO studies raises the possibility of a solvent-dependent duality of mechanism.
Cesium-substituted dodecatungstophosphoric acid on K-10 clay for benzoylation of anisole with benzoyl chloride
Yadav,Asthana,Kamble
, p. 88 - 99 (2003)
Synthesis of cesium-substituted dodecatungstophosphoric acid (Cs 2.5H0.5PW12O40) supported on K-10 clay is reported. The catalyst is fully characterized. It serves as a promising catalyst for the acylation of aromatic compounds. The acylation of anisole with benzoyl chloride was studied systematically by using 20% w/w Cs 2.5H0.5PW12O40/K-10 and this catalyst can be reused without any further chemical treatment, eliminating the effluent disposal problem. This acylation reaction is 100% selective toward 4-methoxybenzophenone, which is the desired perfumery intermediate. The effect of various important kinetic parameters was evaluated systematically to establish that the reaction obeys the Eley-Rideal type of mechanism with a very weak adsorption of the reactants. The reaction is free from any external mass transfer as well as intraparticle diffusion limitations and is intrinsically kinetically controlled.
Green synthesis of 4-methoxybenzophenone from anisole and benzoic acid catalyzed by tungstophosphoric acid supported on MCM-41
Zhang, Huanhuan,Han, Jie,Tian, Fei,Chen, Qingzhi,Wang, Chunzheng,Jin, Hui,Bai, Guoyi
, p. 6731 - 6739 (2015)
Abstract An efficient method was established for the green synthesis of 4-methoxybenzophenone using benzoic acid as acylating agent catalyzed by tungstophosphoric acid (HPW) supported on MCM-41 (HPW/MCM-41). The conversion of benzoic acid reached 97.2 % and the selectivity for 4-methoxybenzophenone was 87.4 % under the optimum conditions over a 50 wt.% HPW/MCM-41 catalyst. HPW is proven to be well deposited on MCM-41, which leads to dealumination of MCM-41 and then offers more active centers, as demonstrated by inductively coupled plasma analysis and NH3 temperature-programmed desorption, accounting for the high catalytic activity of HPW/MCM-41.
A catalytic and mechanistic study of the Friedel-Crafts benzoylation of anisole using zeolites in ionic liquids
Hardacre, Christopher,Katdare, Suhas P.,Milroy, David,Nancarrow, Paul,Rooney, David W.,Thompson, Jillian M.
, p. 44 - 52 (2004)
The Friedel-Crafts benzoylation of anisole with benzoic anhydride to yield 4-methoxybenzophenone has been carried out in a range of ionic liquids using zeolite catalysts. The rates of reaction were found to be significantly higher using ionic liquids compared with organic solvents. Continuous-flow studies of successful ionic liquid systems indicate that the bulk of the catalysis is due to the formation of an acid via the ion exchange of the cation with the protons of the zeolite. The acid liberated was quantified using both titration experiments and ion-exchange experiments using sodium-exchanged zeolites.
Nanostructural zinc oxide hollow spheres: A facile synthesis and catalytic properties
Ashoka, Siddaramanna,Chithaiah, Pallellappa,Thipperudraiah, Kumarappa Veerappa,Chandrappa, Gujjarahalli Thimmanna
, p. 3442 - 3447 (2010)
The development of reproducible procedures for the synthesis and organization of nanostructured metal oxides is important in order to exploit the unique properties of these materials for practical applications. The present work describes the transformation of Zn(NH3)4] 2+ into hollow structured ZnO materials through solvothermal decomposition. An increase in ammonia concentration in the reaction medium, significantly changes the morphology of ZnO from spheres made of nanoparticles (20-30 nm) to hollow spheres composed of nanorods (200-350 nm) or to free microrods as evidenced from scanning and transmission electron micrographs (SEM/TEM). The powder X-ray diffraction (XRD) pattern of ZnO confirms formation of the wurtzite structure. Raman and Energy-dispersive spectroscopic (EDS) studies indicate the presence of oxygen deficiency in ZnO. The investigation on the catalytic behavior of ZnO in the synthesis of (4-methoxyphenyl)(phenyl) methanone (MPPM) by Friedel-Crafts acylation of anisole with benzoyl chloride has also been carried out. The results reveal that the prepared ZnO could produce ～98% of yield compared to 41% produced by commercial ZnO.
Fabrication of a new heterogeneous tungstate-based on the amino-functionalized metal-organic framework as an efficient catalyst towards sonochemical oxidation of alcohols under green condition
Aghajani, Zahra,Najafi, Gholam Reza,Sabaghi, Maryam
, (2020)
Ultrasonic-assisted reactions, as a green technique, are often more efficient compared to those traditional protocols. To this end, the selective and solvent-free oxidation of aromatic alcohols to the corresponding aldehydes and ketones were investigated in the presence of Co-ABDC/W at room temperature under ultrasonic irradiation conditions for the first time in this paper. The structure, particle size, thermal stability, and morphology of the fabricated heterogeneous catalyst and the products were characterized by FT-IR, EDS, FE-SEM, XRD, TGA, and GC analyses. In this regard, immobilization of tungstate had a significant effect on thermal stability (around 450 °C for 40percent weight loss) and catalytic performance. Moreover, the efficiency of two different oxidation methods, including ultrasound irradiations and reflux, were comparatively investigated by GC spectrometry. Obtained sonoxidation results presented higher conversions ranging (84 to 100percent) than reflux condition via shorter reaction times. The influences of the reaction parameters, such as hydrogen peroxide concentration, and catalyst loading, were also investigated. The proposed method offers several advantages, such as excellent conversions, selective oxidations, environmentally-benign procedure, short reaction times, and easy workup. Notably, this is the first report that focuses on using amino-functionalized MOFs with ultrasonic irradiation for selective oxidation reactions.
Palladium-catalyzed aryl-acylation of alkene
Yamane, Motoki,Kubota, Yuko,Narasaka, Koichi
, p. 2105 - 2105 (2002)
Palladium-catalyzed aryl-acylation reactions of alkenes proceed by using acylchromates as the acyl donors. The yield of the product considerably depends on the added phosphine ligands.
Synthesis, coordination and catalytic use of phosphinoferrocene ligands bearing 6-phospha-2,4,6-trioxaadamantane P-donor moieties
?těpni?ka, Petr,Císa?ová, Ivana,Horky, Filip
, (2021/11/11)
1,1’-Bis(diphenylphosphino)ferrocene (dppf) and structurally related ferrocene bis-phosphines are indispensable ligands for coordination chemistry and catalysis. This contribution focuses on the coordination behaviour and catalytic properties of two dppf congeners bearing 1,3,5,7-tetramethyl-2,4,6-trioxa-8-phosphatricyclo[3.3.1.13,7]decane-8-yl groups (CgP) as the P-donor moieties, viz. Ph2PfcCgP (1) and its semi-homologous counterpart Ph2PfcCH2CgP (2; fc = ferrocene-1,1’-diyl). In reactions with a PdCl2 source, compound 1 produced exclusively the cis-chelate complex [PdCl2(1-κ2P,P’)], while the homologated ligand 2 afforded a complex mixture of compounds which equilibrated upon heating in methanol in favour of the symmetrical dimeric complex trans-[(μ-2)PdCl2]2 as a mixture of racemic and meso isomers. Notably, in aqueous Pd-catalysed cyanation of aryl bromides and Suzuki-Miyaura-type cross-coupling of benzoyl chlorides with boronic acids producing benzophenones, catalysts generated in situ from bis-phosphine 1 and Pd(II) sources were often more active than their counterparts resulting from dppf and 2.
