622-45-7Relevant articles and documents
Activation of a Non-Heme FeIII-OOH by a Second FeIII to Hydroxylate Strong C?H Bonds: Possible Implications for Soluble Methane Monooxygenase
Kal, Subhasree,Que, Lawrence
, p. 8484 - 8488 (2019)
Non-heme iron oxygenases contain either monoiron or diiron active sites, and the role of the second iron in the latter enzymes is a topic of particular interest, especially for soluble methane monooxygenase (sMMO). Herein we report the activation of a non-heme FeIII-OOH intermediate in a synthetic monoiron system using FeIII(OTf)3 to form a high-valent oxidant capable of effecting cyclohexane and benzene hydroxylation within seconds at ?40 °C. Our results show that the second iron acts as a Lewis acid to activate the iron–hydroperoxo intermediate, leading to the formation of a powerful FeV=O oxidant—a possible role for the second iron in sMMO.
Kinetics Study of the Esterification Reaction of Cyclohexene to Cyclohexyl Acetate Catalyzed by Novel Br?nsted–Lewis Acids Bifunctionalized Heteropolyacid Based Ionic Liquids Hybrid Solid Acid Catalysts
Guang, Binxiong,Wu, Yuefeng,Liu, Weihua,Wang, Jianhong,Xiao, Yahui,Liu, Yong
, (2021)
A series of Br?nsted–Lewis acids bifunctionalized heteropolyacid based ionic liquids hybrid solid acid catalysts (BLA-HPA-ILs) were synthesized by combining the Br?nsted acidic ionic liquid [Bis–Bs–BDMAEE]HPW12O40 with metallic oxide in different composition ratios and applied in the esterification of cyclohexene to cyclohexyl acetate. Among the synthesized catalysts, the 1/2Cu[Bis–Bs–BDMAEE]HPW12O40 catalyst with Br?nsted and Lewis acidities shown the most excellent catalytic performance for the esterification of cyclohexene with acetic acid. The BLA-HPA-ILs catalysts were characterized by elemental analysis, FT-IR, Py-IR, TG, 1H NMR, SEM and EDX. The effects of reaction temperature, catalyst dosage, and initial reactant molar ratio has been investigated in detail. A pseudohomogeneous (PH) kinetic model was used to correlate the kinetic data in the temperature range of 333.15–363.15?K, and the kinetic parameters were estimated, indicating the results calculated by the kinetic model are well coincidence with the experimental results. Moreover, as a heterogeneous reaction catalyst, 1/2Cu[Bis–Bs–BDMAEE]HPW12O40 could be easily recovered by a simple treatment and reused six times without any obvious decrease in catalytic activity, displaying good reusability. Graphic Abstract: [Figure not available: see fulltext.]
The DMAP-catalyzed acetylation of alcohols - A mechanistic study (DMAP = 4-(dimethylamino)pyridine)
Xu, Shangjie,Held, Ingmar,Kempf, Bernhard,Mayr, Herbert,Steglich, Wolfgang,Zipse, Hendrik
, p. 4751 - 4757 (2005)
The acetylation of tert-butanol with acetic anhydride catalyzed by 4-(dimethylamino)pyridine (DMAP) has been studied at the Becke3 LYP/6-311+G(d,p)//Becke3LYP/6-31G(d) level of theory. Solvent effects have been estimated through single-point calculations
Noncross-linked polystyrene nanoencapsulation of ferric chloride: A novel and reusable heterogeneous macromolecular Lewis acid catalyst toward selective acetylation of alcohols, phenols, amines, and thiols
Alinejad, Sara,Donyapeyma, Ghazaleh,Rahmatpour, Ali
, (2022/01/24)
Ferric chloride has been successfully nanoencapsulated for the first time on a non-cross-linked polystyrene matrix as the shell material via the coacervation technique. The resulting polystyrene nanoencapsulated ferric chloride was used as a novel and rec
Dehydrogenative ester synthesis from enol ethers and water with a ruthenium complex catalyzing two reactions in synergy
Ben-David, Yehoshoa,Diskin-Posner, Yael,Kar, Sayan,Luo, Jie,Milstein, David,Rauch, Michael
supporting information, p. 1481 - 1487 (2022/03/07)
We report the dehydrogenative synthesis of esters from enol ethers using water as the formal oxidant, catalyzed by a newly developed ruthenium acridine-based PNP(Ph)-type complex. Mechanistic experiments and density functional theory (DFT) studies suggest that an inner-sphere stepwise coupled reaction pathway is operational instead of a more intuitive outer-sphere tandem hydration-dehydrogenation pathway.
Trimethylsilyl Esters as Novel Dual-Purpose Protecting Reagents
Chang, Ting-Shuo,Chen, Jyun-Siao,Hsieh, Ya-Chi,Hsu, Hsiao-Lin,Huang, Po-Hsun,Liu, Jen-Wei,Liu, Yu-Hao,Luo, Shun-Yuan,Wu, Hsin-Ru,Wu, Ren-Tsung,Zhang, Kai-Min
supporting information, (2021/12/02)
Trimethylsilyl esters, AcOTMS, BzOTMS, TCAOTMS, etc., are inexpensive and chemically stable reagents that pose a negligible environmental hazard. Such compounds prove to serve as efficient dualpurpose reagents to respectively achieve acylation and trimethylsilylation of alcohols under acidic or basic conditions. Herein, a detailed study on protection of various substrates and new methodological investigations is described.
An efficient, economical and eco-friendly acylation of alcohols and amines by alum doped nanopolyaniline under solvent free condition
Behera, Satyaranjan,Patra, Braja N.
, (2021/08/06)
We report acylation of alcohols and amines employing acetic acid as an acylating agent in solvent free condition by using alum doped nanopolyaniline (NDPANI) as a catalyst. This environmentally benign method does not use corrosive acid anhydrides and acid chlorides for acylation and does not produce waste product. Also, a non-toxic potash alum was used for doping of polyaniline rather than corrosive acids. The reaction conditions represent an advance over established method not only in omitting the need for expensive catalysts or solvents but also in shortening the reaction time significantly. The advantages of this catalyst are non-hazardous, cheap, reusable, easy to prepare and handling.
Synthesis, Characterisation, and Determination of Physical Properties of New Two-Protonic Acid Ionic Liquid and its Catalytic Application in the Esterification
Shahnavaz, Zohreh,Zaharani, Lia,Khaligh, Nader Ghaffari,Mihankhah, Taraneh,Johan, Mohd Rafie
, p. 165 - 172 (2020/10/26)
A new ionic liquid was synthesised, and its chemical structure was elucidated by FT-IR, 1D NMR, 2D NMR, and mass analyses. Some physical properties, thermal behaviour, and thermal stability of this ionic liquid were investigated. The formation of a two-protonic acid salt namely 4,4′-trimethylene-N,N′-dipiperidinium sulfate instead of 4,4′-trimethylene-N,N′-dipiperidinium hydrogensulfate was evidenced by NMR analyses. The catalytic activity of this ionic liquid was demonstrated in the esterification reaction of n-butanol and glacial acetic acid under different conditions. The desired acetate was obtained in 62-88 % yield without using a Dean-Stark apparatus under optimal conditions of 10 mol-% of the ionic liquid, an alcohol to glacial acetic acid mole ratio of 1.3: 1.0, a temperature of 75-100°C, and a reaction time of 4 h. α-Tocopherol (α-TCP), a highly efficient form of vitamin E, was also treated with glacial acetic acid in the presence of the ionic liquid, and O-acetyl-α-tocopherol (Ac-TCP) was obtained in 88.4 % yield. The separation of esters was conducted during workup without the utilisation of high-cost column chromatography. The residue and ionic liquid were used in subsequent runs after the extraction of desired products. The ionic liquid exhibited high catalytic activity even after five runs with no significant change in its chemical structure and catalytic efficiency.
Cyclohexene esterification-hydrogenation for efficient production of cyclohexanol
Zhu, Yunfeng,Gao, Liang,Wen, Langyou,Zong, Baoning,Wang, Hao,Qiao, Minghua
supporting information, p. 1185 - 1192 (2021/02/26)
A novel process based on cyclohexene esterification-hydrogenation for the production of cyclohexanol, the key intermediate in the production of ε-caprolactam, was devised and validated for the first time. In this process, cyclohexene obtained from the partial hydrogenation of benzene is esterified with acetic acid to cyclohexyl acetate, followed by hydrogenation to cyclohexanol. The experimentally determined equilibrium conversion of cyclohexene for cyclohexene esterification at the stoichiometric ratio is always ≥68% in the temperature range of 333-373 K over the commercial Amberlyst 15 catalyst, which is substantially higher than that of cyclohexene hydration. The apparent activation energy (Ea) for the esterification of cyclohexene with acetic acid is 60.0 kJ mol?1, which is lower than that of cyclohexene hydration. In the hydrogenation of cyclohexyl acetate to cyclohexanol, high conversion of 99.5% and high selectivity of 99.7% are obtained on the La-promoted Cu/ZnO/SiO2catalyst prepared by the co-precipitation method. This process shows both a high overall atom economy of 99.4% comparable to that of the cyclohexene hydration process and a much higher catalytic efficiency than the phenol hydrogenation process. On the basis of the above fundamental works, a pilot-scale demonstration unit with a capacity of 8000 tonnes per annum was developed and operated smoothly for more than 1000 h with no indication of deactivation.
METHOD FOR PRODUCING DICARBOXYLIC ACID
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Paragraph 0056-0108; 0112; 0126; 0124, (2021/05/21)
A method for producing dicarboxylic acid. The method includes: subjecting a raw material system including a cyclic olefin and a lower monocarboxylic acid to an addition reaction in the presence of an addition reaction catalyst to generate an intermediate product system including cyclic carboxylic acid ester; and subjecting the intermediate product system including cyclic carboxylic acid ester to a ring-opening and oxidation reaction in the presence of an oxidant and an oxidation catalyst to generate a corresponding dicarboxylic acid product. The addition reaction in the dicarboxylic acid synthesis route achieves a high single-pass conversion rate, and the selectivity of the corresponding cyclic carboxylic acid ester is high. The addition-oxidation synthesis route achieves faster reaction rates for both the addition reaction and oxidation reaction, and high yield of corresponding dicarboxylic acid product. The addition-oxidation based synthesis route is suitable for continuous, stable and large-scale production of corresponding dicarboxylic acid product.
