1680-51-9Relevant academic research and scientific papers
Biomimetic Radical Ring Expansion and Aromatisation; a Model for the Biogenesis of Natural Ring-D Aromatic Steroids
Green, Stuart P.,Whiting, Donald A.
, p. 1754 - 1755 (1992)
Photolysis of the thiohydroxamate 7 generated the carbon radical 9, which rearranged and aromatised to the methyltetralin 8, providing a model for the biogenesis of the insect antifeedant steroid nic-11 from the conventional C/D precursor nic-3 2: photolysis of the isomeric thiohydroxamate 13 gave both methyltetralins 8 and 14, through an unusual rearrangement sequence, possibly involving the benzvalene related radical 17.
Synthesis of Substituted Benzenes via Bi(OTf)3-Mediated Intramolecular Carbonyl Allylation of α-Prenyl or α-Geranyl β-Arylketosulfones
Chang, Meng-Yang,Cheng, Yu-Chieh,Lu, Yi-Ju
, p. 3142 - 3145 (2015)
Intramolecular carbonyl allylation of α-prenyl or α-geranyl β-arylketosulfones 5 in the presence of molecule sieves (MS) affords substituted benzenes 6-7 in moderate to good yields. The facile transformation proceeds by a synthetic sequence starting with the α-prenylation or α-geranylation of 1 and the Bi(OTf)3-mediated annulation of 5 followed by a sequential desulfonative aromatization or then an intramolecular Friedel-Crafts alkylation. A plausible mechanism has been studied and proposed.
Effect of Composition of Cobalt-Molybdenum-Containing Sulfonium Thiosalts on the Hydrogenation Activity of Nanosized Catalysts In Situ Synthesized on Their Basis
Knyazeva,Panyukova,Kuchinskaya,Kulikov,Maximov
, p. 1285 - 1292 (2019)
Abstract: Cobalt-molybdenum-containing thiosalts with different composition of the sulfonium cation are prepared. The activities of sulfide catalysts in situ synthesized on their basis in the hydrogenation of substituted naphthalenes are compared. It is shown that the sulfonium cation composition affects the morphology of the sulfide particles and the phase composition of the catalyst. It is demonstrated that the conversion of model alkyl-substituted bicyclic aromatic hydrocarbons is higher in the presence of the catalyst prepared from the phenylsulfonium thiosalt.
Hydroconversion of 2-methylnaphtalene and dibenzothiophene over sulfide catalysts in the presence of water under CO pressure
Glotov, A. P.,Karakhanov, E. A.,Maximov, A. L.,Vutolkina, A. V.
, p. 280 - 288 (2020)
Unsupported highly dispersed nanosized catalysts based on transition metal sulfides were prepared insitu, in water-oil emulsions, by high-temperature decomposition of oil soluble metal precursors using elemental sulfur as sulfiding agent. Their catalytic activity was tested in hydroconversion of 2-methylnaphtalene and dibenzothiophene at 380 °C under H2 pressure of 5 MPa. In addition, the catalysts were tested in the same reactions in the CO?H2O medium (p(CO) = 5 MPa, the CO: H2O molar ratio was 2: 1, ω(H2O) = 20 wt.%) in which hydrogen is formed through a water gas shift reaction (WGSR). Unsupported Ni?Mo-sulfide catalysts were found to be the most active compared to catalysts supported on alumina. Transmission electron microscopy served to investigate the structure and determine general geometric characteristics of Ni?Mo?S particles formed in toluene—water medium by decomposition of transition metal naphthenates and hexacarbonyls in the presence of elemental sulfur under CO pressure. The method described in this study enables one to synthesize nanosized catalysts with a high content of active sulfide phase.
A new precursor for synthesis of nickel-tungsten sulfide aromatic hydrogenation catalyst
Serdyukov,Kniazeva,Sizova,Zubavichus,Dorovatovskii,Maximov
, (2021)
The unsupported NiWS-catalyst was obtained from the precursor [Ph3S]2Ni(WS4)2 in a hydrocarbon medium (in situ) for hydrogenation bicyclic aromatic compounds. The precursor [Ph3S]2Ni(WS4)2 and the catalyst prepared on its basis were studied by the X-ray diffraction and X-ray absorption methods, XPS and TEM. It was found that the new catalyst formed in situ contains tungsten sulfide and nickel sulfide nanophases. Tungsten sulfide, which has a layered structure, partially forms an insertion compound with nickel that enters between the WS2 layers and bonds covalently to sulfur. The proposed catalyst has proved to be active in the hydrodearomatization processes of model aromatic compounds (naphthalene, methylnaphthalenes) and exhibited the maximum selectivity with the formation of decalins compared to other earlier studied catalysts formed from other precursors in the reaction medium.
Pd-Ni BMNPs Encapsulated in UiO-66 as an Efficient Catalyst for the Activation of “Inert” C?O Bonds
Zhang, Jia-Wei,Li, Dan-Dan,Lu, Guo-Ping,Deng, Tao,Cai, Chun
, p. 4258 - 4263 (2018)
A catalytic system based on Pd?Ni bimetallic nanoparticles (BMNPs) encapsulated in the nanocavities of UiO-66 was established for the activation of C?O bonds in ethers. Pd0.25Ni4@UiO-66 catalyst show excellent catalytic performance in the directly methylation and arylation of ethers under a mild reaction condition. High catalytic activity of the catalyst could be ascribed to the “synergistic effect” between the two metal components and strong interaction between BMNPs and the carrier (UiO-66). BMNPs encapsulated in UiO-66 also guarantee a good reusability of the catalyst, the catalyst delivered high catalytic activity for at least four cycles. Our work highlights the great potential value of ethers as powerful alternatives for aryl halides as well as the bright future of BMNPs and MOFs in the catalysis field.
Synthesis of renewable alkylated naphthalenes with benzaldehyde and angelica lactone
Cong, Yu,Li, Guangyi,Li, Ning,Wang, Aiqin,Wang, Ran,Wang, Xiaodong,Xu, Jilei,Zhang, Tao
supporting information, p. 5474 - 5480 (2021/08/16)
Herein, we report a new route for the synthesis of renewable alkylated naphthalenes (ANs) with benzaldehyde and angelica lactone, two platform compounds that can be derived from lignocellulose.
Nickel–Tungsten and Nickel–Molybdenum Sulfide Diesel Hydrocarbon Hydrogenation Catalysts Synthesized in Pores of Aromatic Polymer Materials
Batryshin,Makeeva,Kulikov,Kardasheva, Yu. S.,Maksimov,Karakhanov
, p. 575 - 580 (2019/06/24)
Abstract: Porous aromatic polymer materials based on tetraphenylmethane molecules linked by methylene groups have been synthesized. By impregnating these materials with nickel–tungsten and nickel–molybdenum thiosalts, catalysts for the hydrogenation of bicyclic aromatic hydrocarbons of the diesel fraction have been prepared. Nanoparticles of the active sulfide phase are formed in support pores during the reaction; it is assumed that after the formation of the nanoparticles, the support material will undergo partial degradation to rearrange the mesoporous structure into a macroporous structure providing the best diffusion of substrates to the surface of the sulfide nanoparticles. The synthesized catalysts have been tested in the hydrogenation of naphthalene and naphthalene derivatives at a hydrogen pressure of 5 MPa and a temperature of 380°C.
Promoted catalysts for hydrogenation of bicyclic aromatic hydrocarbons obtained in situ from molybdenum and tungsten carbonyls
Zakharyan,Onishchenko,Maksimov
, p. 22 - 31 (2018/02/09)
Promoted Мo and W catalysts have been prepared in situ via thermal decomposition of precursors, oil-soluble salts Mo(CO)6, W(CO)6, С°C16H30O4, and NiC16H30O4. TiO2, Al2O3, and ZrO(NO3)2 · 6H2O have been used as the acidic additives. Also, Mo and W unsupported sulfide catalysts have been prepared in the presence of elemental sulfur as the sulfiding agent. The catalysts have been characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. The activity of the catalysts prepared in situ has been evaluated in the hydrogenation reaction of bicyclic aromatic hydrocarbons by the example of model mixtures of 10% solutions of naphthalenes (unsubstituted naphthalene, 1- and 2-methylnaphthalenes, and 1,5- and 2,3-dimethylnaphthalenes) in n-hexadecane. The effect of the precursor/acidic oxide ratio on the activity of the formed catalyst has been found. Hydrogenation of bicyclic aromatic hydrocarbons has been conducted at a hydrogen pressure of 2 and 5 MPa and a temperature of 380 and 400°C for 2 h. Hydrogenation of the unsubstituted aromatic ring has been preferable due to the absence of steric hindrances. The degree of conversion of n-hexadecane under the reaction conditions has been 1.5–7.5% depending on the reaction temperature. It has been found that the activity of the sulfided catalyst in the conversion of 1- and 2-methylnaphthalenes is inferior to the activity of the unsulfided analogue, while partial replacement of TiO2 by Al2O3 results in a decrease in the conversion of the substrates as opposed to the unsulfided catalysts, in which the use of nanocrystalline Al2O3 promotes an increase in the conversion.
Hydrogenation of Aromatic Substrates over Dispersed Ni–Mo Sulfide Catalysts in System H2O/CO
Vutolkina,Makhmutov,Zanina,Maximov,Glotov,Sinikova,Karakhanov
, p. 528 - 534 (2018/07/29)
The activity of unsupported Ni–Mo sulfide catalysts formed during the in situ decomposition of oil-soluble precursors (molybdenum hexacarbonyl, nickel naphthenate) in the hydrogenation of aromatic and naphthene-aromatic compounds is studied. The catalysts are characterized by HRTEM and XPS. Catalytic experiments are conducted at temperatures of 340–380°C and an increased pressure of ?? in the presence of water providing the in situ generation of hydrogen via the water-gas shift reaction. The catalysts exhibit a high activity in the hydrogenation of model substrates (methyl- and dimethyl-substituted naphthalenes and anthracene).
