106-33-2Relevant articles and documents
Surfactant-like Br?nsted acidic ionic liquid as an efficient catalyst for selective Mannich reaction and biodiesel production in water
Vafaeezadeh, Majid,Karbalaie-Reza, Mina,Hashemi, Mohammad Mahmoodi,Soleimany, Kasra Qasempour
, p. 907 - 914 (2017)
Abstract: The current study deals with the applications of a surfactant-like Br?nsted acidic ionic liquid (IL) 1-dodecyl-3-methylimidazolium hydrogen sulfate ([DMIm]HSO4) for Mannich reaction at room temperature. The reaction was efficiently preceded in water as solvent without using any harmful and expensive organic additives. Our findings showed that the reaction is selective for cyclohexanone and no Mannich product was observed when cyclopentanone was used as starting material. Density functional theory (DFT) calculations were performed to provide an evidence about the nature of reactivity of the cyclohexanone/cyclopentanone. The activity of the catalyst was also tested for biodiesel production of fatty acids with methanol and ethanol at mild thermal condition without applying additional water removal steps such as using additives or performing special methodologies like azeotropic distillation. In both reactions, the IL can be recycled and reused several times with relatively constant efficiency. Graphical Abstract: [Figure not available: see fulltext.]
A study on the catalytic activity and theoretical modeling of a novel dual acidic mesoporous silica
Vafaeezadeh, Majid,Fattahi, Alireza
, p. 16647 - 16654 (2014)
A novel mesoporous silica-functionalized dual Bronsted acidic species has been introduced as an efficient catalyst for solvent-free esterification of fatty acids with ethanol. The structure of the catalyst has been characterized by FT-IR spectroscopy, thermal gravimetric analysis (TGA), TEM and N2 adsorption-desorption. TGA of catalyst 1 showed no weight loss before 200 °C, indicating a high degree of hydrophobicity of the surface of the mesoporous silica. TEM images and nitrogen adsorption-desorption showed no noticeable changes to the structure of the catalyst before and after acid treatment. pH metric analysis was performed for the catalyst to determine the loading of the acidic sites. The structure of the catalyst was modeled by mimicking the surface of functionalized silica gel in the form of a cage-like cluster. Various conformers from the proposed structures were selected and optimized at the B3LYP/6-311++G** level of calculation. Natural bond orbital (NBO) analysis was performed to investigate the nature of hydrogen bonding of the catalyst in more detail. Based on the data gained from the optimized structures of the catalyst, a mechanism was proposed for the esterification reaction.
Cross-Coupling between Functionalized Alkylcopper Reagents and Functionalyzed Alkyl Halides
Tucker, Charles E.,Knochel, Paul
, p. 4781 - 4782 (1993)
Functionalized dialkylzincs treated with Me2Cu(CN)(MgCl)2 in DMPU undergo highly chemoselective cross-coupling reactions with functionalized alkyl iodides or benzylic bromides providing polyfunctional products in good to excellent yields.
Effective transesterification of triglyceride with sulphonated modified SBA-15 (SBA-15-SO3H): Screening, process and mechanism
Hu, Ningmeng,Kong, Zhaoni,He, Liang,Ning, Ping,Gu, Junjie,Miao, Rongrong,Sun, Xiangqian,Guan, Qingqing,Duan, Peigao
, p. 846 - 853 (2018)
Different morphologies of ZrO2 were produced by different templates: ZrO2(CaCO3), ZrO2(C12H25SO3Na), ZrO2(C12H25SO4Na), ZrO2(CTAB), and solid superacids, such as ZrO2/SBA-15, SO42-/ZrO2, SO42-/ZrO2/SBA-15, and SBA-15-SO3H. The catalytic transesterification activities of these catalysts were tested. The more highly acidic catalysts and higher surface areas led to higher catalytic activity. In particular, the conversion yield of triglyceride reached 90.1% and was maintained for 90 min at 200 °C with 5.0 wt% SBA-15-SO3H, indicating this material to be one of most effective acid catalysts for the transesterification process. The mechanism indicated that the most important process was the abstraction of hydrogen from alcohols and α-substituted carboxylic glycerides. In the initial transesterification, the alcohol hydrogen atoms could be attracted onto the surface. Then, the nucleophilic attack of the alcohol led to the α-substituted carboxylic glyceride. Finally, monoglycerides, diglycerides or glycerine were released from the surface by proton (H+) replacement.
Efficient and stable PS-SO3H/SiO2 hollow nanospheres with tunable surface properties for acid catalyzed reactions
Chen, Jingjing,Chen, Jian,Zhang, Xiaomin,Gao, Jinsuo,Yang, Qihua
, p. 1 - 8 (2016)
Facile synthesis of hybrid solid acids with finely engineered surface properties was successfully realized via sulfonation of polystyrene (PS) dispersed in nanopores of silica hollow nanosphere modified with different organic group. It was found that octyl or perfluorinated octyl could efficiently increase the surface hydrophobicity of the hybrid solid acids. Benefited from the facile adjustability of the surface properties, the catalytic performance of the solid acids could be readily improved in both the esterification of lauric acid with ethanol and the transterification between tripalmitin and methanol. The solid acid modified with perfluorinated octyl shows even higher activity than liquid sulfuric acid in the transesterification reaction. The octyl group incorporated in the silica shell could also prevent the leaching of PS-SO3H during the catalytic process.
Propoxylated Fatty Thiazole, Pyrazole, Triazole, and Pyrrole Derivatives with Antimicrobial and Surface Activity
El-Sayed, Refat,Khairou, Khalid S.
, p. 661 - 673 (2015)
Lauric acid and propylene oxide were used to modify four biologically active heterocycles (thiazole, pyrazole, triazole, and pyrrole) to synthesize 17 new surfactants. The chemical structures of these surfactants were confirmed using infrared and 1H, and 13C nuclear magnetic resonance (NMR) spectroscopy. The surfactants all show good surface activity, low critical micelle concentration (CMC) values, high cloud points, and tight interfacial packing. All showed antimicrobial activity on both bacteria and fungi. In addition, biodegradation testing demonstrated significant breakdown within seven days.
Zirconium-containing metal organic frameworks as solid acid catalysts for the esterification of free fatty acids: Synthesis of biodiesel and other compounds of interest
Cirujano,Corma,Llabrés I Xamena
, p. 213 - 220 (2015)
Zr-containing metal organic frameworks (MOFs) formed by terephthalate (UiO-66) and 2-aminoterephthalate ligands (UiO-66-NH2) are active and stable catalysts for the acid catalyzed esterification of various saturated and unsaturated fatty acids with MeOH and EtOH, with activities comparable (in some cases superior) to other solid acid catalysts previously reported in literature. Besides the formation of the corresponding fatty acid alkyl esters as biodiesel compounds (FAMEs and FAEEs), esterification of biomass-derived fatty acids with other alcohols catalyzed by the Zr-MOFs allows preparing other compounds of interest, such as oleyl oleate or isopropyl palmitate, with good yields under mild conditions.
Small-Angle Neutron Scattering Study of the Structural Effects of Substitution of Tetramethylammonium for Sodium as the Counterion in Dodecyl Sulfate Micelles
Berr, Stuart S.,Coleman, Michael J.,Jones, Richard R. Marriott,Johnson, James S.
, p. 6492 - 6499 (1986)
Small-angle neutron scattering (SANS) data have been obtained at 303 K for aqueous micellar solutions of CH3(CH2)11SO4Na (sodium dodecyl sulfate (SDS)) and CH3(CH2)11SO4N(CH3)4 (tetramethylammonium dodecyl sulfate (TMADS)) and their deuterated analogues CH3(CH2)10CD2SO4Na (D2-SDS) and CH3(CH2)11SO4N(CD3)4 (D12-TMADS).Results have been obtained for 0.4 mol ddm-3 surfactant in various H2O/D2O mixtures and for TMADS as a function of surfactant concentration in D2O.The SANS data are well described by charged, monodisperse hard spheres interacting through a screened Coulomb potential.The asphericity and the polydispersity of the systems were estimated to be small.The deuterium for the deuterated surfactants lies mainly in the Stern region of the micelle and increases contrast between the hydrocarbon core and the water-saturated Stern layer.Therefore, these deuterated micellar systems were used to determine the radius of the dry core, which was then used in the determination of the structural parameters for the micellar systems.The degree of hydration was determined without resorting to the assignment of the values for the water of hydration for the individual ions present.It was found that TMADS micelles are smaller and have a higher charge, smaller degree of aggregation, and less but more deeply penetrating water than do SDS micelles.Both SDS and TMADS micelles had substantial amounts of hydrocarbon residing in the aqueous Stern layer.
Dehydration reactions in water. Surfactant-type Bronsted acid-catalyzed direct esterification of carboxylic acids with alcohols in an emulsion system [2]
Manabe,Sun,Kobayashi
, p. 10101 - 10102 (2001)
-
Tunable aryl imidazolium ionic liquids (TAIILs) as environmentally benign catalysts for the esterification of fatty acids to biodiesel fuel
Ho, Wen-Yueh,Lin, Wesley,Lin, Yi-Jyun,Luo, Shun-Yuan,Pantawane, Amit,Su, Po-Fang,Thul, Mayur,Tseng, Shao-An,Wu, Hsin-Ru
, (2020/12/02)
Herein, we describe the synthesis of tunable aryl imidazolium ionic liquid catalysts and tested for esterification of fatty acids to biodiesel. In this work, six tunable aryl imidazolium ionic liquids (TAIILs) 1a-1f were prepared. These ionic liquids were used as the economical and reusable catalysts for the synthesis of biodiesel fuels. The reaction has been preceded in a monophase at 80 °C for 4 h, after which the product was separated from the catalyst system by a simple liquid/liquid phase separation at room temperature with excellent yields. With the simple post-process, the catalyst is reusable at least 6 times. This novel method offers a short reaction time, good yields, and environmentally benign characteristics.
Design, Synthesis, and Study of the Insecticidal Activity of Novel Steroidal 1,3,4-Oxadiazoles
Bai, Hangyu,Jiang, Weiqi,Li, Qi,Li, Tian,Ma, Shichuang,Shi, Baojun,Wu, Wenjun
, p. 11572 - 11581 (2021/10/12)
A series of novel steroidal derivatives with a substituted 1,3,4-oxadiazole structure was designed and synthesized, and the target compounds were evaluated for their insecticidal activity against five aphid species. Most of the tested compounds exhibited potent insecticidal activity against Eriosoma lanigerum (Hausmann), Myzus persicae, and Aphis citricola. Compounds 20g and 24g displayed the highest activity against E. lanigerum, showing LC50 values of 27.6 and 30.4 μg/mL, respectively. Ultrastructural changes in the midgut cells of E. lanigerum were detected by transmission electron microscopy, indicating that these steroidal oxazole derivatives might exert their insecticidal activity by destroying the mitochondria and nuclear membranes in insect midgut cells. Furthermore, a field trial showed that compound 20g exhibited effects similar to those of the positive controls chlorpyrifos and thiamethoxam against E. lanigerum, reaching a control rate of 89.5% at a dose of 200 μg/mL after 21 days. We also investigated the hydrolysis and metabolism of the target compounds in E. lanigerum by assaying the activities of three insecticide-detoxifying enzymes. Compound 20g at 50 μg/mL exhibited inhibitory action on carboxylesterase similar to the known inhibitor triphenyl phosphate. The above results demonstrate the potential of these steroidal oxazole derivatives to be developed as novel pesticides.
