26354-94-9Relevant academic research and scientific papers
Heterogeneous Baeyer-Villiger oxidation of cyclic ketones using tert-BuOOH as oxidant
Dutta, Buddhadeb,Jana, Sreyashi,Bhunia, Susmita,Honda, Hisashi,Koner, Subratanath
, p. 90 - 98 (2010)
The [Sn(salen)]2+ complex moiety has been immobilized into NaY zeolite by in situ synthesis of the salen complex in NaY matrix to prepare a new catalyst, Sn(salen)-NaY. The catalyst has been characterized by UV-vis, infrared (IR) spectroscopy, X-ray powder diffraction, M?ssbauer and 119Sn NMR spectroscopy. The catalyst shows impressive catalytic performance (with high selectivity) in Baeyer-Villiger oxidation of various cyclic ketones including 2-adamantanone, cyclohexanone, cyclopentanone, 4-methylcyclohexanone, 2-methylcyclohexanone using tert-butyl hydroperoxide (tert-BuOOH) as an oxidant. The yield of ε-caprolactone from catalytic oxidation of cyclohexanone over Sn(salen)-NaY catalyst was ca. 75%. The catalyst can be recycled for several times without any major decline in catalytic activity.
EFFECT OF PRESSURE ON THE FREE RADICAL REACTIONS OF 2-ALKOXYTETRAHYDROPYRANS
Zhulin, V. M.,Khueidzha, I.,Kabotyanskaya, E. B.,Bogdanov, V. S.,Koreshkov, Yu. D.
, p. 638 - 642 (1992)
In free radical transformations of 2-methoxy- and 2-ethoxytetrahydropyran initiated by tert-butoxy radicals at 130 deg C, the relative rate of formation of δ-valerolactone and valeric acid ester was found to change periodically with increase in the extent of transformation, expressed as tert-butyl alcohol (TBA) concentration.The ratio of lactone: ether concentration is determined not by the pressure (up to 1000 MPa) as suggested earlier, but by the amplitudes and phase displacement of the oscillations of the rates of formation of lactone and ester.These results are explained by changes in the physical structure of the solution in proportion to the buildup of reaction products as a result of which the reactivity of the 2-alkoxytetrahydropyranyl radical changes in respect of rupture of the endocyclic and exocyclic C-O bonds. Keywords: pressure, 2-alkoxytetrahydropyran, free-radical reaction, synthesis of δ-valerolactone.
Preparation and Catalytic Property of Multi-walled Carbon Nanotubes Supported Keggin-Typed Tungstosilicic Acid for the Baeyer-Villiger Oxidation of Ketones
Yang, Zhiwang,Xu, Xueqing,Li, Tianjing,Zhang, Nana,Zhao, Xia,Chen, Wenlong,Liang, Xixi,He, Xinli,Ma, Hengchang
, p. 1955 - 1960 (2015)
Multi-walled carbon nanotubes (MWCNTs) supported HSiW/MWCNTs was successfully prepared and characterized by Fourier transform infrared spectoscopy, X-ray powder diffraction, transmission electron microscopy and N2 adsorption-desorption test. Its catalytic performance for the catalytic Baeyer-Villiger oxidation of cyclic ketones with 30 % H2O2 as oxidants was investigated. It was found that HSiW/MWCNTs was very efficient to transform of some cycloketones to the corresponding lactones with high conversions as well as selectivities. Factors affecting the oxidations and the reusability of the catalyst were also investigated. It was found that the catalyst can be reused seven times in the catalytic oxidation reaction of cyclopentanone without obviously catalytic activity losing in the oxidation. Graphical Abstract: A supported solid acid of HSiW/MWCNTs was used as efficient catalyst for the Baeyer-Villiger oxidation of ketones. High cyclopentanone conversion (98 %) and ε- valerolactone selectivity (99 %) were obtained. The catalyst can be reused at least seven runs in the oxidation of cyclopentanone.
Baeyer-Villiger oxidation of cyclic ketones with aqueous hydrogen peroxide catalyzed by transition metal oxides
Ma, Qingguo,Xing, Wanzhen,Xu, Junhui,Peng, Xinhua
, p. 5 - 8 (2014)
The Baeyer-Villiger oxidation of cyclic ketones to the corresponding lactones using aqueous hydrogen peroxide as an oxidant over transition metal oxides was investigated. MoO3 and WO3 were found to exhibit higher catalytic activity than TiO2, Fe2O 3, Co3O4, ZnO and ZrO2. The high catalytic activity was attributed to the interaction of MoO3/H 2O2 and WO3/H2O2. Additionally, the reaction mechanism on MoO3 and WO3 was proposed.
Synthesis and antimalarial activities of novel 3,3,6,6-tetraalkyl-1,2,4,5-tetraoxanes
Zmitek, Katja,Stavber, Stojan,Zupan, Marko,Bonnet-Delpon, Daniele,Charneau, Sebastien,Grellier, Phillipe,Iskra, Jernej
, p. 7790 - 7795 (2006)
The oxidative system H2O2/fluorinated alcohol (TFE, HFIP) was used for direct acid- and MeReO3-catalyzed synthesis of 1,2,4,5-tetraoxanes from cyclic (C6, C7, and C12) and acyclic ketones. The influence of ring size and alkyl chain length were studied and antimalarial activities of synthetic 3,3,6,6-tetraalkyl-1,2,4,5-tetraoxanes were determined. Variations in their antimalarial activities were significant, although they share similar electrochemical properties of the peroxide bond.
Fabrication of highly active Sn/W mixed transition-metal oxides as solid acid catalysts
Yang, Zhiwang,Niu, Lengyuan,Ma, Zhenhong,Ma, Hengchang,Lei, Ziqiang
, p. 269 - 274 (2011)
Catalytically active Sn/Wmixed transition-metal oxides were prepared by calcination of the corresponding Sn/W hydroxide precursors at different temperatures. The obtained mixed oxides were characterized by physicochemical and spectroscopic methods. With variation of the molar ratios of Sn/W, the prepared Sn/W mixed oxide catalysts had different reaction activities. Thus, the Sn/W-2-800 oxide acted as an effective heterogeneous catalyst for the Baeyer-Villiger oxidation of ketones and the Friedel-Crafts reaction. Many ketones, as well as benzyl alcohol and acetic anhydride, were transformed into the corresponding products with high conversion and selectivity. The catalysts can be easily separated from the reaction mixtures and can be reused for at least five cycles without significant loss of activity. Springer Science+Business Media B.V. 2011.
Baeyer–Villiger Oxidation of Cyclic Ketones by Using Tin–Silica Pillared Catalysts
P?ech, Jan,Carretero, Marta Arroyo,?ejka, Ji?í
, p. 3063 - 3072 (2017)
The Baeyer–Villiger oxidation is an important transformation of ketones into esters and particularly for cyclic ketones to lactones. We report here preparation and catalytic activity of layered Sn–silicate catalysts and mesoporous ordered silica catalysts in this reaction. Sn was introduced by using so-called tin–silica pillaring or by impregnation with a mixture of tetraethylorthosilicate and tin(IV) alkoxide. The prepared catalysts were characterized by XRD, N2 physisorption, SEM, UV/Vis, and inductively coupled plasma optical emission spectroscopy (ICP-OES) techniques and the catalysts were studied in the Baeyer–Villiger oxidation of cyclopentanone, norcamphor, and 2-adamantanone with aqueous hydrogen peroxide. Norcamphor and 2-adamantanone were oxidized easily with selectivity up to 99 %. Sn-MS and IPC-1-SnPI materials exhibited the highest conversions (e.g., norcamphor: Sn-MS 37 %, IPC-1-SnPI 36 % after 8 h vs. Sn-MCM-41 22 %). On the other hand, oxidation of cyclopentanone suffered from product hydrolysis to the corresponding 4-hydroxybutanoic acid.
Synthesis of vinca alkaloid–triphenylphosphine derivatives having potential antitumor effect
Keglevich, András,Szigetvári, áron,Dékány, Miklós,Szántay Jr, Csaba,Keglevich, Péter,Hazai, László
, p. 606 - 609 (2019)
The successful therapy of cancer is still unresolved. For that reason enormous efforts are being made to increase the effectiveness of anticancer drugs and reduce their side effects at least. An important approach to the development of selective molecules is the synthesis of drug conjugates, also called as “hybrids”. Taking this into consideration two Vinca alkaloid derivatives conjugated with triphenylphosphine have been synthetized. The incorporation of the mentioned two pharmacophores in the same molecule could amplify the evolving cumulative antineoplastic impact and/or counterbalance the side effects. Thus a development of hybrid anticancer molecules has been started by synthesis of Vinca alkaloid–triphenylphosphine conjugates, which could have higher efficacies and safety profiles than the present drugs available in market.
ENZIMATIC OLIGOMERISATION VERSUS LACTONISATION OF ω-HYDROXYESTERS
Gutman, Arie L.,Oren, Dalit,Boltanski, Aviv,Bravdo, Tamar
, p. 5367 - 5368 (1987)
Porcine pancreatic lipase in anhydrous organic solvents catalyses almost exclusively the oligomerisation reaction of unsubstituted β, δ and ε-hydroxyacid methyl esters.In contrast, the substituted δ-methyl-δ-hydroxyester undergoes lactonisation.
Baeyer-Villiger oxidation of cyclohexanone with H2O2/acetonitrile over hydrotalcite-like catalysts: Effect of Mg/Al ratio on the ε-caprolactone yield
Olszówka, Joanna,Karcz, Robert,Napruszewska, Bogna D.,Duraczyńska, Dorota,Gawe?, Adam,Bahranowski, Krzysztof,Serwicka, Ewa M.
, p. 196 - 201 (2017)
Phase-pure magnesium-aluminium hydrotalcite-like compounds with molar ratios of Mg/Al ranging from 1.93 to 6.63 were synthesized and characterized with ICP OES, XRD, BET, and Raman spectroscopy. The materials were used as catalysts in the Baeyer-Villiger oxidation of cyclohexanone to ε-caprolactone with H2O2/acetonitrile oxidizing system in mild conditions (70 °C, atmospheric pressure). Initial catalysts activity increased with growing Mg content/basicity, but after completion of the catalytic run best ε-caprolactone yield was obtained for the catalyst with Mg/Al = 5.62. Poorer than expected performance of the material richest in magnesium was attributed to the enhanced leaching of Mg in the mildly acidic reaction environment. The occurrence of the homogeneous catalytic reaction involving leached magnesium has been excluded. Recycling experiments show that leaching of Mg causes partial deactivation, but the catalysts can be easily regenerated and regain the initial performance.
