Article
Chemistry, Applied
Wonjin Jeon, Ji-Yeon Park, Min-Cheol Kim, Seung-Jae Lee, Deog-Keun Kim
Summary: Various transition metal-based Al2O3 catalysts show significantly different activities in the epoxidation of methyl oleate using H2O2 and O2 as oxidants. The reactivity in H2O2-based epoxidation is proportional to the acidity of the catalysts, while in O2-based epoxidation, it depends on the redox properties of the catalysts and O2 behavior on the catalyst surface. Mo and Cu-based catalysts exhibit outstanding performance with H2O2 and O2 via different reaction pathways. These findings provide valuable insights for designing catalytic reaction processes based on the type of oxidizing agent.
Article
Chemistry, Applied
Xiu Gao, Yingqi Zhang, Yanping Hong, Beining Luo, Xianzai Yan, Guoqiang Wu
Summary: In this study, highly efficient, non-corrosive, and green catalytic system for epoxidation of MO was developed using small-size TS-1-s zeolite and Mo/TS-1-bs catalysts. The introduced Mo species were highly dispersed on the outer surface of TS-1-s and easily combined with H2O2 to form electrophilic molybdenum hydroperoxide species, which exhibited high epoxidation activity with MO molecules.
MICROPOROUS AND MESOPOROUS MATERIALS
(2022)
Article
Chemistry, Physical
D. Yu. Yushchenko, Z. P. Pai, Yu. V. Uchenova, T. B. Khlebnikova
Summary: The reaction kinetics of catalytic oxidation of methyl oleate with hydrogen peroxide were studied in a two-phase system, using the bifunctional catalyst [(Oct(n))(3)NMe](3){PO4[WO(O-2)(2)](4)}. The first orders of reaction with respect to the catalyst, substrate, and oxidizing agent were established under the selected reaction conditions. The activation energy was determined to be 47 ± 3 kJ/mol in a temperature range of 313-353 K, with a preexponential factor of (6.0 ± 0.3) x 10(7) L-2 mol(-2) min(-1).
KINETICS AND CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Alexandra Walter, Wolfgang Eisenreich, Golo Storch
Summary: This study reports a photochemical approach using flavin catalysts to oxidize silyl enol ethers to α,β-unsaturated ketones. The catalysts exhibit good stability throughout the reaction and can be successfully applied in subsequent aerobic epoxidation reactions. The sequential catalytic activity of flavin enables rapid diversification of substrates.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Gilvan A. Correia, Marcos L. de Araujo, Wagner A. Carvalho, Mirela Sairre, Giselle Cerchiaro, Lidia S. Shul'pina, Yuriy N. Kozlov, Georgiy B. ShulPin, Alexander M. Kirillov, Dalmo Mandelli
Summary: In this study, the catalytic epoxidation of (R)-carvone by the Ga(NO3)3/H2O2 system was explored, along with the investigation of metal-ligand cooperation using 17 different ligands. The results show that different ligands exhibit different selectivities and efficiencies in the epoxidation reaction.
MOLECULAR CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Nicolaas van Strien, Jukka Niskanen, Anneloes Berghuis, Holger Pohler, Sari Rautiainen
Summary: This study successfully synthesized high yields of FDCA methyl esters and demonstrated the feasibility of the process through scale-up experiments. The results of this study contribute to the valorization of agricultural by-products into fully renewable polyesters.
Article
Thermodynamics
Michael Jabbour, Imed Ben Talouba, Laurent Balland, Nordine Mouhab
Summary: The epoxidation of vegetable oils is an environmentally friendly process for synthesizing platform molecules. Phase transfer catalysis using quaternary ammonium salts, hydrated sodium tungstate, and phosphoric acid improves the kinetics of methyl oleate epoxidation. Among the investigated factors, Aliquat336 shows the fastest reaction kinetics.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Chemistry, Physical
Jia Han, Lei Wang, Wenjin Cao, Qinqin Yuan, Xiaoguo Zhou, Shilin Liu, Xue-Bin Wang
Summary: Size-selective, negative ion photoelectron spectroscopy in conjunction with quantum chemical calculations is employed to investigate the geometric and electronic structures of a protype system in catalytic olefin epoxidation research. The study illustrates the prevalence of a high-lying isomer with asymmetric dual hydrogen-bonding configuration, which is formed by direction-specific electrostatic interactions between [HFIP-H](-) and H2O2. The occurrence of partial charge transfer and proton transfer is observed, and the produced hydroperoxyl radical HOO center dot offers a possible new pathway in olefin epoxidation chemistry.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Shihao Xin, Xinxin Peng, Yao Zhang, Aiguo Zheng, Changjiu Xia, Min Lin, Bin Zhu, Zuoxin Huang, Xingtian Shu
Summary: A binary catalyst composed of tungsten oxide (WO3) and spongy titanosilicate (STS) zeolite is proposed for the oxidative cleavage of methyl oleate (MO). The STS component converts MO to desired products, while reducing the formation of unwanted byproducts. Additionally, STS promotes the precipitation of tungsten species, effectively reducing tungsten leaching. The WO3-STS binary catalyst exhibits high conversion and selectivity, and maintains excellent performance over multiple recycling reactions.
Article
Chemistry, Physical
Marcos Lopes de Araujo, Gilvan Aguiar Correia, Wagner Alves Carvalho, Lidia Sergeevna Shul'pina, Yuriy Nikitovich Kozlov, Georgiy Borisovich Shul'pina, Dalmo Mandelli
Summary: Ethanol and acetol can be oxidized in water at 60 degrees C by the Fe(ClO4)(3)-HClO4-H2O2 system with full conversions, producing formic acid and acetic acid. The oxidation of ethanol and acetol follows different mechanisms, with ethanol oxidation following a chain mechanism and acetol oxidation following a non-chain process. The activation energies for ethanol and acetol oxidation are 24.1 and 14.8 kcal/mol, respectively.
MOLECULAR CATALYSIS
(2021)
Article
Chemistry, Applied
Roman Ottenbacher, Vladimir Kurganskiy, Evgenii P. Talsi, Konstantin P. Bryliakov
Summary: In this study, we reported the enantioselective epoxidation of electron-deficient cis- and trans-alpha,beta-unsaturated amides using the environmentally benign oxidant H2O2. The manganese complexes with bis-amino-bis-pyridine and related ligands as catalysts showed high efficiency and excellent chemo- and enantioselectivity. The presence of NH moiety was found to enhance the enantioselectivity and yield of cis-enamides epoxidation significantly.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Pooja Chaudhary, Geeta Devi Yadav, Krishna K. Damodaran, Surendra Singh
Summary: New chiral Mn(III)-salen complexes were synthesized and evaluated for the asymmetric epoxidation of styrene, showing high yields and promising catalytic activity; the recovered catalysts could be reused for multiple runs, demonstrating good stability and durability.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Physical
Lucas H. R. Passos, Victor Martinez-Agramunt, Dmitry G. Gusev, Eduardo Peris, Eduardo N. dos Santos
Summary: The reduction of esters and aldehydes to alcohols is an important reaction in the chemical industry. The behavior of three commercially available Ru-catalysts for the hydrogenation of these feedstocks is reported. Selective hydrogenation of the ester or aldehyde functionality while keeping the C=C double bond intact is possible, and mild reaction conditions and a sustainable solvent are suitable for these catalytic hydrogenations.
Article
Chemistry, Applied
Marcos Lopes Araujo, Gilvan Aguiar Correia, Wagner Alves Carvalho, Lidia Sergeevna Shul'pina, Yuriy Nikitovich Kozlov, Georgiy Borisovich Shul'pin, Dalmo Mandelli
Summary: This paper investigated the oxidation of 2-butanol using different ligands in aqueous solutions. It was found that the addition of PCA, 5MPCA, and 3TFMPZOLE improved the reaction performance, while other ligands led to lower accumulation of products. DFT studies suggested that metal-ligand pi-back-bonding could be responsible for the reaction activity increase.
Article
Chemistry, Multidisciplinary
Natalie S. Schunck, Stefan Mecking
Summary: Sustainable sources are crucial for chemicals production, and microalgae have the potential to catalytically convert renewable substrates inside living cells, generating valuable building blocks for chemical production.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
