121-89-1Relevant articles and documents
Polyoxovanadate catalysts for oxidation of 1-phenyl ethanol: From the discrete [V4O12]4- and [V10O28]6- anions to the anionic [V6O17]:N4 n - Coordination polymer
Wang, Ke,Xu, Qiaofei,Ma, Pengtao,Zhang, Chao,Wang, Jingping,Niu, Jingyang
, p. 6273 - 6279 (2018)
Three polyoxovanadate-based hybrids {[Ru(phen)3]2[V4O12]}·13H2O (1), [Ru(phen)3]2[V10O28]·15H2O (2), and [Ru(phen)3]2[V6O17]Cl·11H2O (3) (phen = 1,10-phenanthroline) were prepared under hydrothermal conditions and characterized by electron paramagnetic resonance (EPR) spectroscopy, infrared spectroscopy (IR), powder X-ray diffraction (PXRD), thermogravimetric (TG) analysis, X-ray photoelectron spectroscopy (XPS), and single crystal X-ray diffraction analysis. Although the structures of both the cyclic vanadate [V4O12]4- and the [V10O28]6- anions are well-known, interestingly, a novel 1-dimensional (1-D) coordination polymer [V6O17]n4n- anion was constructed from tetranuclear [V4O12]4- and dinuclear [V2O7]4- building blocks, which were linked alternately through corner-shared oxygen atoms. Furthermore, the negative charges of polyoxovanadate [V4O12]4-, [V10O28]6- and [V6O17]4- anions were balanced by two [Ru(phen)3]2+/3+ complex cations. The catalytic properties of compounds 1-3 for the oxidation of 1-phenyl ethanol by tert-butyl hydroperoxide (TBHP) were investigated, and the results demonstrated that 1 and 3 exhibited excellent catalytic activities for the oxidation of 1-phenyl ethanol under mild catalytic conditions.
Nonselective bromination-selective debromination strategy: Selective bromination of unsymmetrical ketones on singly activated carbon against doubly activated carbon
Choi, Han Young,Chi, Dae Yoon
, p. 411 - 414 (2003)
(Matrix presented) We have found a new synthetic method for the preparation of the α-bromoketones that are brominated in the less activated terminal position of unsymmetrical ketones. Brominations in short reaction times (kinetically controlled) provided internally brominated compounds as a major product. However, brominations in longer reaction times (thermodynamically controlled) gave more of the terminally brominated compound through the reversible reaction by Br2 and produced hydrogen bromide. Several brominated compounds at the terminal position were successfully prepared through the new synthetic route.
Ortho Enhancement in the Ozone-Mediated Nitration of Some Aromatic Carbonyl Compounds with Nitrogen Dioxide
Suzuki, Hitomi,Murashima, Takashi,Tatsumi, Atsuo,Kozai, Iku
, p. 1421 - 1424 (1993)
Alkyl aryl ketones react smoothly with nitrogen dioxide at low temperatures in the presence of ozone to give a mixture of ortho and meta nitration products (o/m = 1.1-3.8/1.0), the former becoming predominant with the increasing size of alkyl moiety.
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Barkenbus,Clements
, p. 1369 (1934)
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A Stable Polyoxometalate-Based Metal-Organic Framework as Highly Efficient Heterogeneous Catalyst for Oxidation of Alcohols
Li, Dandan,Xu, Qiaofei,Li, Yingguang,Qiu, Yueting,Ma, Pengtao,Niu, Jingyang,Wang, Jingping
, p. 4945 - 4953 (2019)
A novel copper-containing 3D polyoxometalate-based metal-organic framework (POMOF), H[Cu5ICuII(pzc)2(pz)4.5{P2W18O62}]·6H2O (HENU-1, HENU = Henan University; Hpzc = pyrazine-2-carboxylic acid, pz = pyrazine), was successfully isolated by a one-step hydrothermal method. In this compound, the {P2W18} polyanion acts as a seven-connected linker bridging adjacent 2D double-layer networks, as well as a template to induce the formation of the desired 3D framework. Particularly, the pz ligands are generated from pzc ligands in situ during the reaction process. HENU-1 exhibits not only good stability in air but also tolerance to acidic and basic media. It was first employed as a highly efficient heterogeneous catalyst for the oxidation of 1-phenylethanol into acetophenone, which shows 97% yield using tert-butyl hydroperoxide as oxidant with a turnover frequency of up to 9690·h-1, and was reused for at least five cycles without significant catalytic activity loss. No POM leaching or framework decomposition was observed in our study.
Catalyst- and acid-free Markovnikov hydration of alkynes in a sustainable H2O/ethyl lactate system
Dandia, Anshu,Saini, Pratibha,Chithra,Vennapusa, Sivaranjana Reddy,Parewa, Vijay
, (2021/03/15)
An efficient and sustainable protocol for the hydration of alkynes has been developed under metal/acid/catalyst/ligand-free conditions in a water/ethyl lactate mixture. The hydrogen-bond network in the ethyl lactate and water mixture plays a crucial and decisive role in activating the alkynes for hydration to afford the corresponding methyl ketones. This strategy gives the Markovnikov (ketone) addition product selectively over other possible products. The essential role of hydrogen bonding has been confirmed by experimental and theoretical techniques. A probable mechanism has been suggested by various control tests. The efficacy of the method has been further explored for the competent production of value-added α,β-unsaturated carbonyl compounds through the reaction of aldehydes with alkynes as ketonic surrogates. The environmentally benign hydration method takes place under mild conditions, has broad functional-group compatibility, and uses the ethyl lactate/water (1:3) medium as a “green alternative” in the absence of any hazardous, harmful, or expensive substances.
g-C3N4/H3PW4Mo8O40 S-scheme photocatalyst with enhanced photocatalytic oxidation of alcohols and sulfides
Fazlali, Farnaz,Khazaee, Zeynab,Najminejad, Zohreh,Nejat, Razieh,Shahraki, Somaye
, (2021/08/16)
In this work, graphitic carbon nitride (g-C3N4) decorated with molybdenum-substituted tungstophosphoric acid as a novel photocatalyst (H3PW4Mo8O40/g-C3N4) was used to catalyze the oxidation of alcohols and sulfides. H3PW4Mo8O40/g-C3N4 (PW4Mo8/g-C3N4) displays higher photocatalytic activity under visible light irradiation for the oxidation of alcohols and sulfides compared with Keggin/g-C3N4 (PW12/g-C3N4). To obtain the optimum value, molybdenum substitution contents (H3PW12-xMoxO40) were changed from x = 4 to 12. The results showed that PW4Mo8 produces the best yield under visible-light irradiation. The results showed that PW4Mo8 was the best sample. The reaction rate increase can be due to the redox and acid properties of PW4Mo8/g-C3N4. This study provides a new insight for the preparation of highly efficient photocatalysts for the oxidation of organic compounds.
Ru(iii) -based polyoxometalate tetramers as highly efficient heterogeneous catalysts for alcohol oxidation reactions at room temperature
Li, Huafeng,Ma, Pengtao,Niu, Jingyang,Song, Junpeng,Wang, Jingping,Wang, Yaqiong,Zhao, Xue,Zou, Yan
, p. 12664 - 12673 (2021/09/28)
A novel ruthenium-containing polyoxometalate-based organic-inorganic hybrid, K4Na9H7.4[(AsW9O33)4(WO2)4{Ru3.2(C3H3N2)2}]·42H2O (1), was successfully synthesized by a one-step hydrothermal method under acidic conditions, which applied a self-assembly strategy between inorganic polyoxometalate based on trivacant [B-α-AsW9O33]9?{AsW9} fragments and an organic ligand, imidazole (C3H4N2). Compound1was further characterized by single-crystal X-ray diffraction, PXRD, IR spectroscopy, UV-Vis spectroscopy, ESI-MS, elemental analysis and TGA. Single-crystal X-ray diffraction data reveal that the polyanion consists of four trivacant Keggin-type polyanion {AsW9} building blocks bridged by four {WO6} units, leading to a crown-shaped tetrameric structure [(AsW9O33)4(WO2)4{Ru3.2(C3H3N2)2}]20.4?. The ESI-MS result reveals that the polyanion unit has excellent structural integrity in water. Moreover, the catalysis study of1was also further investigated, and the experimental results indicate heterogeneous catalyst1presents high efficiency (yield = 98%), excellent selectivity (>99%), and good recyclability for the oxidation of 1-(4-chlorophenyl)ethanol to 4′-chloroacetophenone with commercially available 70% aqueoustert-butyl hydroperoxide {TBHP (aq.)} as the oxidant at room temperature.