- Selectivity in sorption and hydrogenation of methyl oleate and elaidate on MFI zeolites
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Different zeolites were tested for selective removal of methyl elaidate (trans isomer) from an equimolar mixture with methyl oleate (cis isomer). Sorption experiments of the geometric isomers show that only ZSM-5 samples with reduced Al content in the framework are able to discriminate among the bent cis and the linear trans fatty acid methyl esters. Hydrogenation experiments of equimolar methyl oleate and elaidate mixtures at low temperature (65 °C) and high hydrogen pressure (6.0 MPa), using Pt catalysts, confirm this result. Only with a Pt/Na-ZSM-5 catalyst outspoken selectivity for the hydrogenation of the trans isomer is obtained. In order to prepare a selective Pt/ZSM-5 catalyst, the influence of Pt addition (impregnation, ion-exchange and competitive ion-exchange) and Pt activation (different calcination and reduction temperatures) on the Pt-distribution and Pt particle size was investigated using SEM, bright-field and HR TEM, EDX, electron tomography, CO-chemisorption, XPS, XRD, and UV-vis measurements. The best result in terms of hydrogenation activity and selectivity is obtained with a Pt/ZSM-5 catalyst, which is prepared via competitive ion-exchange, followed by slow calcination up to 350 °C under high O2 flow and a reduction up to 500 °C under H2. This preparation method leads to a Pt/ZSM-5 catalyst with the best Pt distribution and the smallest Pt clusters occluded in the zeolite structure. Finally, the influence of zeolite crystal size, morphology, and elemental composition of ZSM-5 on hydrogenation activity and selectivity was investigated in detail.
- Philippaerts, An,Paulussen, Sabine,Turner, Stuart,Lebedev, Oleg I.,Van Tendeloo, Gustaaf,Poelman, Hilde,Bulut, Metin,De Clippel, Filip,Smeets, Pieter,Sels, Bert,Jacobs, Pierre
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- A new reagent for the methylation of carboxyl groups
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A new reagent for the preparation of methyl esters of carboxylic acids is described. The reaction involves treatment of acids with methanesulfonyl chloride in pyridine at 0°C.
- Siddiqui, Bina S.,Firdous,Begum, Sabira
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- Synthesis and characterization of composites based on polyaniline and styrene-divinylbenzene copolymer using benzoyl peroxide as oxidant agent
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This work presents a method to prepare composites based on polyaniline (Pani) and styrene-divinylbenzene copolymers (SD) by in situ polymerization of aniline using benzoyl peroxide as oxidant agent. The composites were obtained from copolymers with two degrees of porosities which have higher and lower surface areas. Emeraldine Pani was prepared using hydrochloric acid as dopant. One cycle or four cycles of aniline polymerization were performed. The copolymers and their respective composites characterizations were performed by infrared spectroscopy, thermogravimetric analysis, physical nitrogen adsorption-desorption measurements, morphology analysis, elemental analysis and determination of Br?nsted acid sites. The Pani was distributed overall porous SD copolymer producing composites with high surface area. Then, they were evaluated as catalysts for esterification reaction of a fat acid. It was found that that composites prepared with four cycles of in situ polymerization presented best catalytic activity than one cycle composites.
- Moura,Assis,Franco,Antoniosi Filho,Rabelo
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- The dichapetalins - A new class of triterpenoids
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Further to our recent report on dichapetalin A, we describe the isolation and structure elucidation by spectroscopic methods of dichapetalins B-H from the roots of Dichapetalum madagascariense. These compounds constitute a novel class of triterpenoids. Dichapetalin A shows a strong and selective cytotoxic activity.
- Addae-Mensah, Ivan,Waibel, Reiner,Asunka, Stephen A.,Oppong, Isaac V.,Achenbach, Hans
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- Comparison of phosphatidylcholine vesicle properties related to geometrical isomerism
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Glycerophosphatidylcholine containing trans-unsaturated fatty acid residues was prepared by reaction of the corresponding naturally occurring cis lipid with photochemically generated thiyl radicals. This modified lipid was chosen as the simplest model for gaining some insights of the complex scenario of membrane formation, in connection with the role of lipid geometry and the predominance of cis lipids in eukaryotic cells. The critical aggregation concentration for the spontaneous formation of vesicles was determined for cis and trans isomers with cis-parinaric acid used as a fluorescent probe and it was found to be similar for both lipids. Vesicle dimensions were investigated by light scattering and electron microscopy, and the type of fatty acid residues influenced the vesicle diameter, with a decrease along the series cis > trans > saturated. Fluorescence measurement of dye release from trans and cis vesicles showed also a different permeability. A picture emerged of the geometrical isomer preference in cells as a process driven by natural selection during the life evolution of different organisms, both in terms of compartment dimensions and membrane functionality.
- Ferreri, Carla,Pierotti, Silvia,Barbieri, Andrea,Zambonin, Laura,Landi, Laura,Rasi, Silvia,Luisi, Pier Luigi,Barigelletti, Francesco,Chatgilialoglu, Chryssostomos
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- HYDROGENATION OF FATTY ACIDS ESTERS. III. HYDROGENATION OF METHYL (9Z,12Z)-OCTADECADIENOATE AND METHYL (9Z,12Z,15Z)-OCTADECATRIENOATE
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The title hydrogenation catalyzed by nickel(II) 2,4-pentanedionate-triethylaluminium system has been studied with the use of combination of initial rate measurements with time changes of product distribution.It was found that the hydrogenation of methyl (9Z,12Z)-octadecadienoate is first order in the octadecadienoate.Similar results were obtained also for (9Z,12Z,15Z)-octadecatrienoate.The course of both reactions has been described by models involving set of parallel and consecutive hydrogenation steps and reversible isomerizations.Computer rate constants for hydrogenation of methyl (9Z,12Z)-octadecadienoate support qualitative conclusions deduced from the product analysis.
- Krupickova, Jana,Vcelak, Jaroslav,Hetflejs, Jiri
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- Mesoporous RuO2/TiO2 composites prepared by cyclodextrin-assisted colloidal self-assembly: Towards efficient catalysts for the hydrogenation of methyl oleate
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Mesoporous RuO2/TiO2 composites were prepared using a template-directed colloidal self-assembly approach combined with a cyclodextrin (CD)-assisted aqueous impregnation method. The supramolecular assemblies formed between the randomly methylated β-cyclodextrin (RaMeβ-CD) and the block copolymer P123 acted as a template for the formation of a highly porous TiO2 network over which uniform dispersion of ruthenium nanoparticles was achieved. By combining dynamic light scattering, X-ray diffraction, N2-adsorption, temperature-programmed reduction, field-emission scanning electron microscopy and high-resolution transmission electron microscopy, we show that CD-based assemblies provide a versatile and easily accessible toolbox with different functionalities for generating metal-supported catalysts with controlled pore architecture and uniform metal distribution. The performance of these supported catalysts was evaluated in the liquid phase hydrogenation of methyl oleate (MO, C18:1) to methyl stearate (MS, C18:0). Control of ruthenium dispersion into the large pores of RaMeβ-CD-P123-templated TiO2 material enhanced catalyst activity and selectivity for the hydrogenation of the internal C = C bond and permitted catalyst separation and reuse without loss of activity. Our findings highlight the pivotal role played by the CD-based assemblies on the performance of supported ruthenium catalysts.
- Bleta, Rudina,No?l, Sébastien,Addad, Ahmed,Ponchel, Anne,Monflier, Eric
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- Chromatographic analyses of fatty acid methyl esters by HPLC-UV and GC-FID
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An analytical method using high performance liquid chromatography with UV detection (HPLC-UV) (method A) was used for simultaneous determination of total amounts of triacylglycerides, diacylglycerides, monoacylglycerides and fatty acid methyl esters in alcoholysis of different oil (cotton, canola, sunflower, corn and soybean) samples. Analyses were carried out at 40 °C for 20 min using a gradient of methanol (MeOH) and 2-propanol-hexane 5:4(v/v) (PrHex):100percent of MeOH in 0 min, 50percent of MeOH and 50percent of PrHex in 10 min maintained with isocratic elution for 10 min. Another HPLC-UV method (method B) with acetonitrile isocratic elution for 34 min was used to determine the fatty acid composition of oils analyzing their methyl ester derivatives. Contents were determined with satisfactory repeatability (relative standard deviation, RSD 2 > 0.99) and sensitivity (limit of quantification). Method B was compared with an official gas chromatographic method with flame ionization detection (GC-FID) from American Oil Chemists' Society (AOCS) in the determination of fatty acid methyl esters (FAME) in biodiesel real samples.
- Carvalho, Myller S.,Mendonc?a, Ma?rcio A.,Pinho, David M. M.,Resck, Ine?s S.,Suarez, Paulo A. Z.
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- AN ACYLATED SITOSTEROL GLUCOSIDE FROM ALISMA PLANTAGO-AQUATICA
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A phytosterol glucoside acylated with stearic acid has been isolated from the methanol extract of the rhizome of Alisma Plantago-aquatica, and its structure has been determined as sitosterol-3-O-6-stearoyl-β-D-glucopyranoside by spectroscopic data and chemical conversions.Key Word Index-Alisma Plantago-aquatica; Alismataceae; sitosterol-3-O-6-stearoyl-β-D-glucopyranoside; sitosterol; methyl stearate.
- Pei-Wu, Geng,Fukuyama, Yoshiyasu,Rei, Wang,Jinxian, Bao,Nakagawa,Kazuyuki
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- A direct novel synthesis of highly uniform dispersed ruthenium nanoparticles over P6mm ordered mesoporous carbon by host-guest complexes
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We report a novel concept to prepare a highly ordered mesoporous carbon with a uniform dispersion of ruthenium nanoparticles of 1-2 nm size range using a nano-templating method, based on the combined utilization of a β-cyclodextrin host-guest complex and ruthenium trichloride as respective sources of carbon and metal. The composite material synthesized (Ru@MCA-2) through the polymerization and carbonization of these metallo-supramolecular assemblies possesses high surface area and high pore volume after the removal of the silica template and exhibits high catalytic activity in the hydrogenation of unsaturated fatty acid methyl esters. The reusability of this nanoreplicated catalyst is also demonstrated. This journal is the Partner Organisations 2014.
- Gokulakrishnan,Peru,Rio,Blach,Leger,Grosso,Monflier,Ponchel
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- Bioactive dammarane triterpenes from the mangrove Plant Bruguiera gymnorrhiza
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Three new dammarane triterpenes, bruguierins A-C (1-3), were isolated from a petroleum ether extract of the flowers of Bruguiera gymnorrhiza. Their structures were determined on the basis of physical and spectroscopic data interpretation. With stably transfected HepG2 cells, the three isolates activated antioxidant response element (ARE luciferase activation) with EC50 values of 7.8, 9.4, and 15.7 μM, respectively. Bruguierin A (1) also inhibited phorbol ester-induced NFκB (nuclear factor-κB) luciferase activation with an IC50 value of 1.4 μM and selectively inhibited cyclooxygenase-2 (COX-2) activity with an IC50 value of 0.37 μM. Compounds 2 and 3 were not active in these bioassays.
- Homhual, Sudarat,Bunyapraphatsara, Nuntavan,Kondratyuk, Tamara,Herunsalee, Angkana,Chaukul, Wongsatit,Pezzuto, John M.,Fong, Harry H. S.,Zhang, Hong-Jie
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- Three New Derivatives and Others Constituents from the Roots and Twigs of Trilepisium?madagascariense DC
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Three new compounds, trilepisflavene (1), trilepisdepsidone (2), and daturadiol stearate (3), together with nine known compounds, 2-hydroxy-4-[(4-hydroxy-2-methoxy-6-methylbenzoyl)oxy]-6-methylbenzoic acid (4), lichexanthone (5), naringenin (6), 3′,4′,5,7-tetrahydroxyflavanone (7), 2-hydroxybenzoic acid (8), methyl 2,4-dihydroxy-6-methylbenzoate (9), β-amyrin (10), eurothridiol palmitate (11), and β-sitosterol (12), were isolated from the AcOEt extract of the twigs and the roots of Trilepisium?madagascariense. Acetylation of eurothridiol palmitate was carried out and a new acetylated derivative (13) was obtained. The structures of the isolated and acetylated compounds were elucidated on the basis of spectroscopic analysis. Antimicrobial activity of all these compounds was evaluated using Mueller–Hinton broth (MHB) and Mueller–Hinton agar (MHA) method. Trilepisdepsidone, 2-hydroxy-4-[(4-hydroxy-2-methoxy-6-methylbenzoyl)oxy]-6-methylbenzoic acid, 3′,4′,5,7-tetrahydroxyflavanone, and naringenin exhibited moderate to weak antimicrobial activity.
- Ango, Yves P.,Kapche, Gilbert D. W. F.,Kuete, Victor,Mapitse, Renameditswe,Yeboah, Samuel O.,Ngadjui, Bonaventure T.
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- Microwave-Assisted Synthesis and Characterization of Stearic Acid Sucrose Ester: A Bio-Based Surfactant
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Sugar esters of fatty acids are bio-based surfactants that were synthesized by transesterification of table sugar (sucrose) with stearic acid methyl ester (SAME) in high yield and purity using an optimized microwave-assisted method. The maximum surfactant product yield of 88.2% was obtained by combining reactants with potassium methoxide and irradiating the mixture with microwaves to achieve an ideal reaction temperature of 132 °C over 21 min. The synthetic procedure described herein minimized undesirable sugar pyrolysis as evidenced by retention of white color characteristic of a pure bio-based surfactant product. The experiment implemented Box–Behnken design for response surface methodology to refine reaction parameters for optimal product yield. The following parameters were augmented: the irradiation time, the mole ratio of catalyst to sucrose, and temperature.
- Kondamudi, Narasimharao,McDougal, Owen M.
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- Effects of Si/Al ratio and Pt loading on Pt/SAPO-11 catalysts in hydroconversion of Jatropha oil
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A series of Pt/SAPO-11 catalysts were prepared with various Si/Al ratios and Pt loadings and characterized by using BET, XRD, XRF, and CO pulse adsorption, as well as 29Si NMR and NH3-TPD techniques. Their catalytic performances in hydroconversion of Jatropha oil were tested with a fixed-bed flow reactor system. The isomerization activity increased with the Si/Al ratio because there were more medium acidic sites on the SAPO-11 supports. Pt/SAPO-11 catalysts with a Si/Al ratio of 0.4 demonstrated high activity for both deoxygenation and isomerization among catalysts with the same Pt loading. The deoxygenation, isomerization and cracking activities strongly depended on the Pt loading. The best activity was observed for the sample with a 3 wt% Pt loading, which generated an 83% yield of iso-C15-18 hydrocarbons under the LHSV of 0.5 h-1. Based on the mechanistic study of hydroconversion of methyl oleate, a reaction network for the hydroconversion of Jatropha oil was suggested.
- Chen, Ning,Gong, Shaofeng,Shirai, Hisakazu,Watanabe, Toshitaka,Qian, Eika W.
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- GERMACRANOLIDES, A GUAIANOLIDE WITH A β-LACTONE RING AND FURTHER CONSTITUENTS FROM GRAZIELIA SPECIES
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An investigation of three Grazielia species afforded, in addition to known compounds, several new sesquiterpene lactones, eight germacranolides, two melampolides and one guaianolide as well as three diterpenes, two geranylgeraniol derivatives and a labda-diene.Three of the sesquiterpene lactones had an additional β-lactone ring, one an acid function, and two others unusual ester functions.The structures were elucidated by spectroscopic methods and some chemical transformations.The chemotaxonomic situation is discussed briefly.Key Word Index- Grazielia intermedia; G. dimorpholepsis; G. serreta; Compositae; Eupatorieae; sesquiterpene lactones; germacranolides; guaianolides; melampolides; β-lactones; diterpenes.
- Bohlmann, Ferdinand,Zdero, Christa,King, Robert M.,Robinson, Harold
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- Iron complex with ionic tag-catalyzed olefin reduction under oxidative conditionsa-A different reaction for iron
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An iron(III) complex with ionic tags was applied to the reduction of alkenes in imidazolium-based ionic liquids (ILs) under oxidative conditions. The catalyst is very efficient to promote reactions of biomass derivatives. At least ten recycling reactions were performed without any loss of catalytic activity. Some important mechanistic insights for this new reaction are also provided based mostly on electrospray ionization quadrupole-time of flight mass spectrometry (ESI-QTOF-MS).
- Dos Santos, Marcelo R.,Gomes, Alexandre F.,Gozzo, Fabio C.,Suarez, Paulo A. Z.,Neto, Brenno A. D.
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- Comparative biochemistry of fatty acid and macrolide antibiotic (brefeldin A). Formation in Penicillium brefeldianum
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The stereochemistry of the D labeling of mycelial steric and oleic acids by 13C2H3CO2H in vivo in Penicillium brefeldianum is the same at their even numbered, non-starting group positions as found for saturated fatty acid biosynthesis in two other eukaryotes. This conclusion was reached by comparing the D labeling at C-10 of methyl stearate with that of methyl oleate as determined by 13C NMR spectroscopy. Since brefeldin A is labeled by CD3CO2H at C-6 and C-8 with the enantiotopic configurational result, the stereochemistry of antibiotic formation either differs at two points from fatty acid formation; or the C-6 and C-8 configuration of 1 is determined by some process unique to cyclopentane ring formation, but not by reduction of enolylthioester intermediates of its carbon chain assembly process.
- Hutchinson,Shu Wen,McInnes,Walter
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- A NEW HYDROXYOLEFINIC ACID FROM PLANTAGO MAJOR SEED OIL
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Key Word Index - Plantago major; Plantaginaceae; greater plantain; seed oil; 9-hydroxy-cis-11-octadecenoic acid.A new isomer of ricinoleic acid has been found as a minor constituent (1.5percent) of the seed oil of Plantago major.This previously unknown β-hydroxyolefinic acid, 9-hydroxy-cis-11-octadecenoic, was characterized by IR, 1H NMR and oxidative cleavage, and the structure was supported by MS.
- Ahmad, Mohammad Shamim,Ahmad, Moghis U.,Osman, S. M.
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- Tunable aryl imidazolium ionic liquids (TAIILs) as environmentally benign catalysts for the esterification of fatty acids to biodiesel fuel
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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.
- Ho, Wen-Yueh,Lin, Wesley,Lin, Yi-Jyun,Luo, Shun-Yuan,Pantawane, Amit,Su, Po-Fang,Thul, Mayur,Tseng, Shao-An,Wu, Hsin-Ru
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- Protic ionic liquids from di- or triamines: even cheaper Br?nsted acidic catalysts
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Dicationic and tricationic ionic liquids, synthesised by proton transfer from sulfuric acid and corresponding di- and triamines, were characterised and used as Br?nsted acidic catalysts in biodiesel production. It has been demonstrated that the new ionic liquids are less expensive than those based on monoamines (even on triethylamine) and are highly acidic. Their performance in a model catalytic esterification reaction surpassed that of sulfuric acid and other literature reports, due to the capability of the ionic liquids to absorb water while phase-separating the ester, thereby shifting the reaction equilibrium towards products. The overall catalytic performance was an interplay between acidity (quantified by Gutmann AN) and physical properties: density and viscosity, which enabled easy phase separation, thereby separating water from the ester. The substrate scope and recycling studies have demonstrated that the new ionic liquids are robust and recyclable catalysts.
- Barteczko, Natalia,Brz?czek-Szafran, Alina,Byrne, Emily,Chrobok, Anna,Kolanowska, Anna,Swad?ba Kwa?ny, Ma?gorzata,Szelwicka, Anna,Wi?c?awik, Justyna
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p. 4421 - 4429
(2021/06/28)
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- Novel synthesized microporous ionic polymer applications in transesterification of Jatropha curcas seed oil with short Chain alcohol
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New suites of sulfonic acid-functionalized microporous ionic polymers (PIPs) catalysts were synthesized with polymer, alkyl bromides, and 1, 3-propane sultone via a two-step procedure. The synthesized microporous PIP catalysts were characterized using FT-IR, SEM-Mapping, XPS, N2 adsorption–desorption isotherms, solid NMR spectroscopy, and element analysis. Esterification of several fatty acids with ethanol, which was used as a model reaction in the stabilization of Jatropha curcas seed oil, was checked over functionalized PIP. We tested the catalytic performance of PIP-C8 on the synthesis of fatty acid esters via the transesterification of J. curcas seed oil with a mixture of short-chain alcohols such as ethanol, ethanol–to–diethyl carbonate (1;1 molar ratio), and ethanol–to–dimethyl carbonate (1:1 molar ratio) with 170 mg of PIP-C8 at reflux temperature with agitation. The PIP-C8 catalyst was particularly effective, having achieved yields of 85%, 94%, and 70% for J. curcas seed oil with ethanol, J. curcas seed oil with ethanol–to–DEC, and J. curcas seed oil with ethanol–to–DMC, respectively, under the optimized reaction conditions. The catalyst could be recycled more than five times without significant deactivation. Kinetic studies performed at different temperatures revealed that the conversion of oleic acid to an ethyl ester follows a first-order reaction. The best catalysts with microporous structure (average pore diameter: 1.7–1.9 nm, pore volume: 0.23–0.33 cm3 g–1) and –SO3H density (0.70–0.84 mmol/gcat) were obtained by 1, 3-propane sultone of the chemically activated. The results indicate that the site activity of functionalized microporous ionic polymer materials shows promising approach for the development of environmentally friendly technology.
- Chang, Tao,Hao, Yongjing,Jinxi, Jinxi,Kai, Kai,Panchal, Balaji,Qin, Shenjun,Sun, Yuzhuang,Zhao, Cunling,Zhao, Qiaojing,Zhu, Zheng
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- Highly ordered mesoporous functionalized pyridinium protic ionic liquids framework as efficient system in esterification reactions for biofuels production
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Polysiloxane acidic ionic liquids containing pyridinium trifluoroacetate salts (PMO-Py-IL) were synthesized from pyridine containing organosilane precursors. Characterization by SEM, XRD, TGA, and nitrogen porosimetry confirmed that both pyridinium cation and trifluoroacetate anion were successfully incorporated within the organosilica network. The resulting organic-inorganic hybrid nanomaterial (PMO-Py-IL) was studied as nanocatalyst in free fatty acids esterification into biodiesel-like compounds. Remarkably, the synergistic hydrophilic/hydrophobic effect of pyridinium and trifluoroacetate ionic liquid in the well-ordered channels of PMO-Py-IL nanomaterial enhanced the activity toward sustainable biodiesel-like esters production. More importantly, PMO-Py-IL nanocatalyst also exhibited an exceptional activity and stability. The catalyst could be easily separated to reuse at least in ten reactions runs preserving almost intact its catalytic activity under otherwise identical conditions to those employed for the fresh catalysts.
- Luque, Rafael,Rajabi, Fatemeh
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- Sulfonated Hyper-cross-linked Porous Polyacetylene Networks as Versatile Heterogeneous Acid Catalysts
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Two highly sulfonated micro/mesoporous polymers, P(1,3-DEB)-SO3H and P(1,4-DEB)-SO3H, with permanent porosity, the specific surface area about 550 m2 ? g?1 and the content of SO3H groups of 2.7 mmol ? g?1 were prepared as new acid Porous Polymer Catalysts, PPCs. The PPCs were achieved by easy sulfonation of parent hyper-cross-linked micro/mesoporous polyacetylene-type networks resulting from a chain-growth homopolymerization of 1,3- and 1,4-diethynylbenzenes. New PPCs are reported as highly active and reusable heterogeneous catalysts of esterification of fatty acids with methanol and ethanol, Prins cyclization of aldehydes with isoprenol and intramolecular Prins cyclization of citronellal to isopulegol. The catalytic activity of the micro/mesoporous PPCs (TON values up to 522 mol ? mol?1) was higher than that of commercial polymer-based heterogeneous catalyst Amberlyst 15 possessing gel texture without permanent pores and that of p-toluenesulfonic acid applied as a homogeneous catalyst.
- Sekerová, Lada,B?ezinová, Pavlína,Do, Thuy Tran,Vysko?ilová, Eli?ka,Krupka, Ji?í,?erveny, Libor,Havelková, Lucie,Bashta, Bogdana,Sedlá?ek, Jan
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p. 1075 - 1084
(2020/01/03)
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- Anionic Amphiphilic Cyclodextrins Bearing Oleic Grafts for the Stabilization of Ruthenium Nanoparticles Efficient in Aqueous Catalytic Hydrogenation
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Oleic succinyl β-cyclodextrin was proved to be efficient for the stabilization of ruthenium nanoparticles (NPs) in aqueous medium. These NPs were characterized by FTIR spectroscopy and transition electron microscopy (TEM). The catalytic activity of these NPs was evaluated in the aqueous hydrogenation of petrosourced and biosourced unsaturated compounds such as benzene and furfural derivatives. The catalytic system can be easily recycled and reused up to nine runs without any loss of activity and selectivity, demonstrating its robustness.
- Cocq, Aurélien,Léger, Bastien,No?l, Sébastien,Bricout, Hervé,Djeda?ni-Pilard, Florence,Tilloy, Sébastien,Monflier, Eric
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p. 1013 - 1018
(2019/12/27)
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- Ruthenium-catalyzed hydrogenation of CO2as a route to methyl esters for use as biofuels or fine chemicals
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A novel robust diphosphine-ruthenium(ii) complex has been developed that can efficiently catalyze both the hydrogenation of CO2 to methanol and its in situ condensation with carboxylic acids to form methyl esters; a TON of up to 3260 is achievable for the CO2 to methanol step. Both aromatic and aliphatic carboxylic acids can be transformed to their corresponding methyl esters with high conversion and selectivity (17 aliphatic and 18 aromatic examples). On the basis of a series of experiments, a mechanism has been proposed to account for the various steps involved in the catalytic pathway. More importantly, this approach provides a promising route for using CO2 as a C1 source for the production of biofuels, fine chemicals and methanol.
- Li, Yong,Liu, Qingbin,Ma, Yanping,Solan, Gregory A.,Sun, Wen-Hua,Wang, Zheng,Zhang, Qiuyue,Zhao, Ziwei,Zhong, Yanxia
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p. 6766 - 6774
(2020/08/25)
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- Identification and α -Glucosidase Inhibitory Activity of Meroterpenoids from Hericium erinaceus
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Hericium erinaceus is a very popular edible and medicinal mushroom used for the treatment of enervation and gastrointestinal diseases in Eastern Asia. Chemical investigation on the fruiting body of Hericium erinaceus led to the isolation of 4 new (1 - 4) and 10 known meroterpenoids (5 - 14). The structures of new compounds were determined via analysis of NMR and MS data in combination with chemical derivatization. The inhibitory activities of 1 - 14 against α -glucosidase were evaluated using p -nitrophenyl- α -D-glucopyranoside, sucrose, or maltose as substrate. Compounds 6, 9, 11 - 13 were demonstrated to show the α -glucosidase inhibitory activities. This work confirms the potential of H. erinaceus in the treatment of diabetes.
- Bao, Li,Chen, Baosong,Han, Junjie,Liu, Hongwei,Ma, Ke,Wang, Wenzhao
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p. 571 - 578
(2020/06/03)
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- 1,3-Dibromo-5,5-dimethylhydantoin as a Precatalyst for Activation of Carbonyl Functionality
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Activation of carbonyl moiety is one of the most rudimentary approaches in organic synthesis and is crucial for a plethora of industrial-scale condensation reactions. In esterification and aldol condensation, which represent two of the most important reactions, the susceptibility of the carbonyl group to nucleophile attack allows the construction of a variety of useful organic compounds. In this context, there is a constant need for development of and improvement in the methods for addition-elimination reactions via activation of carbonyl functionality. In this paper, an advanced methodology for the direct esterification of carboxylic acids and alcohols, and for aldol condensation of aldehydes using widely available, inexpensive, and metal-free 1,3-dibromo-5,5-dimethylhydantoin under neat reaction conditions is reported. The method is air- and moisture-tolerant, allowing simple synthetic and isolation procedures for both reactions presented in this paper. The reaction pathway for esterification is proposed and a scale-up of certain industrially important derivatives is performed.
- ?ebular, Klara,Bo?i?, Bojan ?.,Stavber, Stojan
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supporting information
(2019/08/01)
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- Robust acidic pseudo-ionic liquid catalyst with self-separation ability for esterification and acetalization
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The novel acidic pseudo-ionic liquid catalyst with self-separation ability has been synthesized through the quaternization of triphenylphosphine and the acidification with silicotungstic acid. The pseudo-IL showed high activities for the esterification with average conversions over 90%. The pseudo-IL showed even higher activities for acetalization than traditional sulfuric acid. The homogeneous catalytic process benefited the mass transfer efficiency. The pseudo-IL separated from the reaction mixture automatically after reactions, which was superior to other IL catalysts. The high catalytic activities, easy reusability and high stability were the key properties of the novel catalyst, which hold great potential for green chemical processes.
- Shi, Yingxia,Liang, Xuezheng
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p. 1413 - 1421
(2019/05/04)
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- Biomolecule-derived supported cobalt nanoparticles for hydrogenation of industrial olefins, natural oils and more in water
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Catalytic hydrogenation of olefins using noble metal catalysts or pyrophoric RANEY nickel is of high importance in the chemical industry. From the point of view of green and sustainable chemistry, design and development of Earth-abundant, less toxic, and more environmentally friendly catalysts are highly desirable. Herein, we report the convenient preparation of active cobalt catalysts and their application in hydrogenations of a wide range of terminal and internal carbon-carbon double bonds in water under mild conditions. Catalysts are prepared on multi-gram scale by pyrolysis of cobalt acetate and uracil, guanine, adenine or l-tryptophan. The most active material Co-Ura/C-600 showed good productivity in industrially relevant hydrogenation of diisobutene to isooctane and in natural oil hardening.
- Pews-Davtyan, Anahit,Scharnagl, Florian Korbinian,Hertrich, Maximilian Franz,Kreyenschulte, Carsten,Bartling, Stephan,Lund, Henrik,Jackstell, Ralf,Beller, Matthias
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supporting information
p. 5104 - 5112
(2019/09/30)
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- Synthesis of mesoporous ZSM-5 zeolites and catalytic cracking of ethanol and oleic acid into light olefins
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Conversion of biomass-derived chemicals into light olefins is a promising method to maintain sustainable development of light olefin industry. In this study, three mesoporous ZSM-5 zeolites (MZSM-5-A, MZSM-5-B and MZSM-5-C) with major pore diameter about 4.8 nm, 16 nm and 22 nm were synthesized using a hydrothermal method by utilizing different templates. The catalytic activity of catalysts was studied by catalytic cracking of ethanol and oleic acid. The influence of reaction temperature on conversion and product selectivity was investigated. The characterization of ZSM-5 samples showed that the orders of the external surface area and mesopore volume were MZSM-5-C > MZSM-5-B > MZSM-5-A > conventional HZSM-5. In ethanol to light olefin reaction, MZSM-5-C achieved the highest light olefin yield (318.3 mL g?1) and ethylene selectivity (42.3%) at 400 °C. In oleic acid to light olefin reaction, MZSM-5-B achieved a complete conversion of oleic acid at 500 °C, and obtained the highest light olefin selectivity (38.1%) at 550 °C. The difference may be relevant to the size and chemical structure of feedstock molecular as well as the acidity of catalysts. Regardless of ethanol or oleic acid as feedstock, introduction of mesopore in zeolites significantly enhanced the light olefin yield and selectivity.
- Zhao, Tingting,Li, Fuwei,Yu, Hongchang,Ding, Shilei,Li, Zhixia,Huang, Xinyuan,Li, Xiang,Wei, Xiaohan,Wang, Zhenlin,Lin, Hongfei
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p. 101 - 110
(2019/02/24)
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- Catalytic transfer hydrogenation of oleic acid to octadecanol over magnetic recoverable cobalt catalysts
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Efficient transformation of biomass into fuel and chemicals under mild conditions with cost-effective and environmentally friendly characters is highly desirable but still challenging. Herein, a scalable and Earth-abundant cobalt catalyst was used for selective catalytic transfer hydrogenation (CTH) of unsaturated fatty acids to fatty alcohols with sustainable isopropanol as a hydrogen donor. By tuning the surface Co composition by varying the reduction temperature, the catalytic performance could be easily boosted. At 200 °C in 4 h, the optimal catalyst Co-350 (reduced at 350 °C) gives 100% oleic acid conversion with 91.9% octadecanol selectivity. Various characterization studies reveal that the co-existence of Coδ+ and Co0 over the cobalt core might be responsible for its high performance for CTH of oleic acid. This catalyst could be magnetically separated and is highly stable for reusing ten times. Moreover, this cobalt catalyst is relatively cheap and easy to scale-up, thus achieving a low-cost transformation of biomass into high value-added chemicals.
- Wang, Juncheng,Nie, Renfeng,Xu, Ling,Lyu, Xilei,Lu, Xiuyang
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p. 314 - 320
(2019/01/28)
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- Synthesis, structural characterization, and reactivity of (thiolato)bismuth complexes as potential water-tolerant Lewis acid catalysts
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We have synthesized bismuth complexes incorporating polydentate mono-and di-thiolate ligands and examined their utility as water-tolerant Lewis acid catalysts. The reaction of Bi(OAc)3 or Bi(NO3)3·5H2O and the corresponding mono-or di-thiol(ate) yielded the compounds [(SNNS)Bi(OAc)] (4), [(SNNSPr)Bi(OAc)] (5), [(NNS2)Bi(OAc)] (6), [(ONS2)Bi(OAc)] (7), [(ONS2)Bi(NO3)] (8), and [(NNS)2Bi][NO3] (9) [H2(SNNS) = N,N′-dimethyl-N,N′-bis(2-mercaptoethyl)ethylenediamine; H2(SNNSPr) = N,N′-diethyl-N,N′-bis(2-mercaptoethyl)propanediamine; H2(NNS2) = N,N-diethyl-N′,N′-bis(2-mercaptoethyl)ethanediamine; H2(ONS2) = 2-methoxyethyl-bis(2-mercaptoethyl)amine; H(NNS) = N,N-diethyl-N′-(2-mercaptoethyl)ethanediamine]. The solid-state structures of 4-8 show similar distorted pentagonal pyramidal geometries at the bismuth centre with a thiolate sulfur atom in the axial site, whereas 8 shows second structural arrangement with a distorted trigonal bipyramidal geometry at bismuth. The cation of 9 shows two NNS-bonded ligands and a distorted octahedral geometry at bismuth. Two-dimensional NMR studies of 4-8 show geminal 1H coupling in-SCH2CH2N-groups and suggests strong dative Bi-N intramolecular interactions. Bi(NO3)3·5H2O and BiCl3 show high activity toward the esterification of stearic acid, Bi(NO3)3·5H2O, and 4-7 and 9 show high activity toward the transesterification of methyl stearate in butanol, and 7 shows moderate activity as a catalyst for the transesterification of glyceryl trioctanoate in methanol.
- Briand, Glen G.,Decken, Andreas,Shannon, Whitney E.M.M.,Trevors, Eric E.
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p. 561 - 569
(2018/06/07)
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- Esterification of aryl/alkyl acids catalysed by n-bromosuccinimide under mild reaction conditions
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N-halosuccinimides (NXSs) are well-known to be convenient, easily manipulable and low-priced halogenation reagents in organic synthesis. In the present work, N-bromosuccinimide (NBS) has been promoted as the most efficient and selective catalyst among the NXSs in the reaction of direct esterification of aryl and alkyl carboxylic acids. Comprehensive esterification of substituted benzoic acids, mono-, di- and tri-carboxy alkyl derivatives has been performed under neat reaction conditions. The method is metal-free, air- and moisture-tolerant, allowing for a simple synthetic and isolation procedure as well as the large-scale synthesis of aromatic and alkyl esters with yields up to 100%. Protocol for the recycling of the catalyst has been proposed.
- ?ebular, Klara,Bo?i?, Bojan ?.,Stavber, Stojan
-
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- Efficient synthesis of esters through oxone-catalyzed dehydrogenation of carboxylic acids and alcohols
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Since esters are important organic synthesis intermediates, an environmentally friendly oxone catalyzed-esterification of carboxylic acids with alcohols has been developed. A series of carboxylic acid esters are obtained in high yield. This strategy requires mild reaction conditions, providing an attractive alternative for the construction of valuable carbonyl esters. Electron-rich and electron-deficient groups are compatible with the standard conditions and a variety of substrates are demonstrated. Moreover, the reaction could easily be adapted to typical prodrugs, drugs and gram-scale synthesis.
- Hou, Fei,Wang, Xi-Cun,Quan, Zheng-Jun
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supporting information
p. 9472 - 9476
(2019/01/03)
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- Sulfonic acid-functionalized organic knitted porous polyaromatic microspheres as heterogeneous catalysts for biodiesel production
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The use of renewable energy sources decreases the consequences of greenhouse gas emission from fossil fuels. Biodiesel, an easily burning and biodegradable fuel, is an alternative to conventional diesel fuel. The esterification of long-chain fatty acids and transesterification of triglycerides are two major reactions widely used to convert vegetable oils or animal fats into biodiesel. As solid acid catalysts are considered promising candidates for biodiesel production, we have synthesized a series of organic knitted porous polyaromatics (OPPs) using pyrene, anthracene, and naphthalene as monomers via Friedel-Crafts alkylation, followed by crosslinking reactions. The resultant polymers showed good surface morphology, stability and swelling property, high capacity for functionalization due to the unreacted bromomethyl groups on the surface, and excellent hydrophobicity. The sulfonated polymer microspheres obtained by the surface sulfonation showed good surface acidity; thus, they can be employed as heterogeneous solid acid catalysts for the esterification of long-chain fatty acids and transesterification of triglycerides, and they are reusable without any leaching of functional groups.
- Varyambath, Anuraj,Kim, Mi-Ra,Kim, Il
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p. 12745 - 12753
(2018/08/04)
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- Clean and Green Procedure for the Synthesis of Biodiesel from the Esterification of Free Fatty Acids and Alcohol Catalyzed by 6-O-(sulfobutyl)-Β-cyclodextrin
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The catalyst of 6-O-(sulfobutyl)-β-cyclodextrin (SB-CD) is renewable, non-toxic, environmentally benign and biocompatible, which could be used as efficient and recyclable catalyst for the synthesis of biodiesel from free long-chain fatty acids with low-chain alcohols as substrates. The reaction was accomplished at 60°C for 1.5 h, while the products were separated from the catalyst system by liquid/liquid at room temperature with good conversion of 91–98%. The catalyst can be reused for 10 times. The novel and clean procedure offers advantages including short reaction time, good conversion, operational simplicity, and environmentally benign characteristics.
- Zhang, Guangqing,He, Leqin,Yuan, Mingxia,Li, Hui,Chang, Tao,Qin, Shenjun
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p. 1123 - 1128
(2018/10/24)
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- H-Transfer reactions of internal alkenes with tertiary amines as H-donors on carbon supported noble metals
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A hydride transfer reaction with tertiary amines was observed in the presence of noble metals on a carbon support. Hydride transfer had been documented previously in terms of activated allyl-type carbon-carbon double bonds containing carbonyl derivatives in the presence of triethyl amine (conjugate reduction). The proposed mechanism is a hydride transfer reaction in which the metal serves as the reaction partner of the hydrido-metal iminium adduct formation. The saturation of a non-activated internal double bond containing compound, such as methyl oleate and trans-5-decene as substrates, was observed for the first time in this work. The pre-reduced catalyst samples showed high activity; in the presence of Pd/C, Pt/C and Rh/C partial to complete conversion was detected at 140 °C in a p-xylene solvent without molecular hydrogen. Higher molecular weight byproducts of the amines were formed, while in the case of the substrates negligible amounts of unreacted but double bond migrated species were present. There is a possibility of usage of alkyl amines other than triethylamine; thus use of tributyl-, tripentyl-, trihexylamine and N,N-diisopropylethylamine, as well as cyclic 1-ethylpyrrolidine and 1-ethylpiperidine, was investigated. Cyclic amines and diisopropyl derivatives as H sources produced the highest conversion, while amines with longer alkyl chains showed minor activity. As a clear indication of H-donation, the formation of unsaturated amine species such as 1-ethyl-pyrrole and pyridine was observed.
- Yang, Guoju,Bauer, Thomas J.,Haller, Gary L.,Baráth, Eszter
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supporting information
p. 1172 - 1177
(2018/02/21)
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- Lipoteichoic acid anchor triggers Mincle to drive protective immunity against invasive group A Streptococcus infection
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Group A Streptococcus (GAS) is a Gram-positive bacterial pathogen that causes a range of diseases, including fatal invasive infections. However, the mechanisms by which the innate immune system recognizes GAS are not well understood. We herein report that the C-type lectin receptor macrophage inducible C-type lectin (Mincle) recognizes GAS and initiates antibacterial immunity. Gene expression analysis of myeloid cells upon GAS stimulation revealed the contribution of the caspase recruitment domain-containing protein 9 (CARD9) pathway to the antibacterial responses. Among receptors signaling through CARD9, Mincle induced the production of inflammatory cytokines, inducible nitric oxide synthase, and reactive oxygen species upon recognition of the anchor of lipoteichoic acid, monoglucosyldiacylglycerol (MGDG), produced by GAS. Upon GAS infection, Mincle-deficient mice exhibited impaired production of proinflammatory cytokines, severe bacteremia, and rapid lethality. GAS also possesses another Mincle ligand, diglucosyldiacylglycerol; however, this glycolipid interfered with MGDG-induced activation. These results indicate that Mincle plays a central role in protective immunity against acute GAS infection.
- Imai, Takashi,Matsumura, Takayuki,Mayer-Lambertz, Sabine,Wells, Christine A.,Ishikawa, Eri,Butcher, Suzanne K.,Barnett, Timothy C.,Walker, Mark J.,Imamura, Akihiro,Ishida, Hideharu,Ikebe, Tadayoshi,Miyamoto, Tomofumi,Ato, Manabu,Ohga, Shouichi,Lepenies, Bernd,Van Sorge, Nina M.,Yamasaki, Sho
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p. E10662 - E10671
(2018/11/20)
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- Efficient flow fischer esterification of carboxylic acids with alcohols using sulfonic acid-functionalized silica as supported catalyst
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Flow Fischer esterification of carboxylic acids using hydroxy-substituted sulfonic acid-functionalized silica (HOSAS) packed into a stainless steel column reactor was investigated. HO-SAS well catalyzed flow esterification of long chain carboxylic acids with methanol within 3min of residence time at 110°C, and the methyl esters were quantitatively obtained. The flow esterification protocol was applied to the synthesis of a variety of esters (19 examples) and scalable synthesis was also successful.
- Furuta, Akihiro,Fukuyama, Takahide,Ryu, Ilhyong
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p. 607 - 612
(2017/06/19)
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- Surfactant-like Br?nsted acidic ionic liquid as an efficient catalyst for selective Mannich reaction and biodiesel production in water
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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.]
- Vafaeezadeh, Majid,Karbalaie-Reza, Mina,Hashemi, Mohammad Mahmoodi,Soleimany, Kasra Qasempour
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p. 907 - 914
(2017/02/26)
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- Synthesis, characterization and reactivity of (dithiolato)indium complexes
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We have synthesized indium complexes incorporating tetradentate dithiolate ligands. The 1:1 reaction of InX3 (X?=?OAc, NO3) and the corresponding dithiol or dithiolate yielded the compounds [(SOOS)In(py)(NO3)] (1), [(SNNS)In(OAc)] (2), [In(μ-SNNS)2(μ-OMe)In][NO3] (3), [(SNNSPr)In(OAc)] (4), [(NNS2)In(OAc)] (5) and [(NNS2)In(NO3)] (6) [H2(SOOS)?=?2,2′-(ethylenedioxy)diethanethiol; H2(SNNS)?=?N,N′-dimethyl-N,N′-bis(2-mercaptoethyl)ethylenediamine; H2(SNNSPr)?=?N,N′-diethyl-N,N′-bis(2-mercaptoethyl)propanediamine; H2(NNS2)?=?N,N-diethyl-N′,N′-bis(2-mercaptoethyl)ethanediamine]. The solid-state structures of 1, 2 and 4–6 are mononuclear and show a tetradentate SOOS/SNNS/NNS2 ligand and a distorted octahedral (1) or trigonal bipyramidal (2, 4–6) coordination geometry at indium. Compound 3 is dinuclear, with the indium centres bridged by a -OMe oxygen atom and a thiolate sulfur atom of chelating tetradentate ligands, respectively. InX3 (X?=?Cl, NO3) were found to be useful Lewis acid catalysts for the aldol reaction of benzaldehyde and 1-(trimethylsiloxy)cyclohexene under ambient conditions, while compounds 1–6 show moderate activity as catalysts for the esterification of stearic acid and transesterification of methyl stearate and glyceryl trioctanoate.
- Anderson, Timothy S.,Briand, Glen G.,Brüning, Ralf,Decken, Andreas,Margeson, Matthew J.,Pickard, Heidi M.,Trevors, Eric E.
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p. 101 - 108
(2017/07/24)
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- Synthesis and antimicrobial studies of 5-n-alkyl-1,3,4-oxadiazole-2-thiol derivatives from fatty acids
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The novel 5-N-alkyl-1,3,4-oxadiazole-2-thiol derivatives have been synthesized by esterification of fatty acid followed by reaction the ester with hydrazine hydrate. The acid hydrazide was converted to 1,3,4-oxadiazole by ring closure mechanism. The synthesized compounds have been characterized by physical (melting point and TLC) and spectral (IR, 1H NMR and mass) data. All the compounds were screened for their antimicrobial activity. The compounds 3F1 & 3F4 showed good inhibition activity against all four types of bacteria; while compound 3F2 & 3F3 shown moderate activity.
- Naga Sudha,Yella Subbaiah,Srikanth,Venkata Ramana Reddy,Sneha Latha,Vijaya Lakshmi
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p. 2369 - 2371
(2017/10/31)
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- Mesoporous Ag1(NH4)2PW12O40 heteropolyacids as effective catalysts for the esterification of oleic acid to biodiesel
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Mesoporous Ag1(NH4)2PW12O40 (AgN-PW) was developed by co-doping silver and ammonium ions into phosphotungstic acid as an efficient and stable catalyst for free fatty acid esterification, and its physicochemical properties were derived from X-ray diffraction (XRD), thermogravimetric (TG) analysis, Fourier transform infrared (FT-IR) spectra, N2 adsorption-desorption, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The final catalyst showed a typical Keggin structure of heteropoly acids. This solid acid exhibited remarkable catalytic activity (nearly 100% conversion) in the esterification of oleic acid with methanol for biodiesel production under optimum synthesis conditions. Furthermore, due to the high activity presented in various esterifications of free fatty acids and non-edible oils with high acid values, the mesoporous AgN-PW material was proven to be an environmentally friendly catalyst for industrial biodiesel production.
- Zhang, Qiu-Yun,Wei, Fang-Fang,Li, Qian,Huang, Jin-Shu,Feng, Yun-Mei,Zhang, Yu-Tao
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p. 51090 - 51095
(2017/11/16)
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- Long-chain α-ω Diols from renewable fatty acids via tandem olefin metathesis-ester hydrogenation
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Long chain α-ω diols were readily accessed from renewable fatty acid methyl esters following an orthogonal tandem self-metathesis-ester hydrogenation protocol. By adding a base and a bidentate ligand, the metathesis catalysts were transformed in situ into efficient ester hydrogenation catalysts. The selectivity of the hydrogenation reaction was tuned towards the exclusive formation of either the unsaturated or the saturated diol by modifying the ligand/catalyst ratio. An orthogonal tandem cross-metathesis-ester hydrogenation reaction was also applied for the synthesis of a fragrance compound.
- Gonzalez-De-Castro, Angela,Cosimi, Elena,Aguila, Mae Joanne B.,Gajewski, Piotr,Schmitkamp, Mike,De Vries, Johannes G.,Lefort, Laurent
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supporting information
p. 1678 - 1684
(2017/06/07)
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- Linear Selective Isomerization/Hydroformylation of Unsaturated Fatty Acid Methyl Esters: A Bimetallic Approach
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Herein, we report about the development of an isomerization/hydroformylation tandem reaction to selectively convert fatty acid methyl esters into asymmetric α,ω-functionalized aldehyde esters. An orthogonal tandem catalytic system consisting of a palladium-based isomerization catalyst and a rhodium-based hydroformylation catalyst was developed, using methyl 3-hexenoate as a model substrate. Using this catalyst, high yields (81% at 99% conversion) and regioselectivities (l/b-ratio of 98/2) toward the desired terminal hydroformylation product are obtained in the conversion of methyl 3-hexenoate under mild conditions. Ethyl 4-decenoate was subsequently applied as a second model substrate to identify challenges associated with the longer chain length of the unsaturated ester. Finally, methyl oleate was converted using the developed catalyst system. High aldehyde yields of 74% (at 99% conversion) with an l/b-ratio of 91/9 are obtained.
- Gaide, Tom,Bianga, Jonas,Schlipk?ter, Kim,Behr, Arno,Vorholt, Andreas J.
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p. 4163 - 4171
(2017/06/19)
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- Methanolysis of Jatropha curcas oil using K2CO3/CaO as a solid base catalyst
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Biodiesel, fatty acid methyl ester produced by the transesterification of vegetable oil with methanol, is a promising alternative to petroleum-based diesel fuel. In the present study, the methanolysis of high free fatty acid (FFA) Jatropha curcas oil in a transesterification reaction using K 2 CO 3 /CaO solid base catalyst was studied. The various reaction parameters in the transesterification reaction were also discussed. The catalyst was characterized by means of Fourier transform infrared, X-ray diffraction, temperature programmed desorption of CO 2, scanning electron microscopy, particle size analyzer, true density, and surface area analyzer. The optimum conversion of jatropha oil was 92% when the transesterification reaction was carried out at 70? C with 10:1 molar ratio of methanol to oil at reaction time of 3 h and catalyst amount of 6 wt%. The efficiency of catalysts in the methanolysis of jatropha oil was also investigated.
- Sahu, Gajanan,Saha, Sujan,Datta, Sudipta,Chavan, Prakash,Naik, Satyanarayan
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p. 845 - 861
(2018/01/12)
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- Dammarane triterpenoids from Carnauba, Copernicia prunifera (Miller) H. E. Moore (Arecaceae), wax
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Phytochemical investigation from carnauba (Copernicia prunifera) wax led to the identification of sixteen dammarane–type triterpenes, including thirteen new characterized as: (24R*)-methyldammara-20,25-dien-3α-ol and a mixture of alkyl (24R*)-methyldammar-25-en-20-ol-3β-carboxylates, together with three previously described triterpenes: carnaubadiol, (24R*)-methyldammara-20,25-dien-3β-ol and (24R*)-24-methyldammara-20,25-dien-3-one. Moreover, four fatty alcohols (eicosanol, docosanol, tetracosanol and hexacosanol) as well as four sterols (cholesterol, campesterol, stigmasterol, and sitosterol) were also obtained. These compounds were isolated using classical chromatographic methods and their structures were determined by spectroscopic and chemical methods.
- De Almeida, Buana C.,Araújo, Bruno Q.,Barros, Elcio D. S.,Freitas, Samya D. L.,Maciel, Dayany S. A.,Ferreira, Ari J. S.,Guadagnin, Rafael C.,Vieira, Gerardo M.,Lago, Jo?o H. G.,Chaves, Mariana H.
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p. 1371 - 1376
(2017/07/13)
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- Methods for Preparing Phenolic Branched Chain Alkyl Fatty Acids or Esters Thereof and Methods for Killing Microorganisms
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Disclosed are methods for preparing phenolic branched chain fatty acids or alkyl esters thereof, involving subjecting in a pressurized container (a) at least one phenolic compound, (b) unsaturated fatty acids having 6 to 25 carbon atoms, alkyl esters thereof, or mixtures thereof, and (c) H-ferrierite zeolite catalyst in the presence of distilled water or alcohol and a nitrogen atmosphere at a temperature of about 100° C. to about 400° C. and a pressure of about 10 to about 1000 psi, and isolating saturated phenolic branched chain fatty acids or alkyl esters thereof or mixtures thereof. Also disclosed are methods for killing microorganisms on or in an object, involving contacting said object with an effective microorganisms killing amount of a composition comprising phenolic branched chain fatty acids or alkyl esters thereof, and optionally a carrier; the phenolic branched chain fatty acids or alkyl esters thereof may be produced by the methods described herein.
- -
-
Paragraph 0054
(2017/12/17)
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- Metathesis of renewable polyene feedstocks – Indirect evidences of the formation of catalytically active ruthenium allylidene species
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Cross-metathesis (CM) of conjugated polyenes, such as 1,6-diphenyl-1,3,5-hexatriene (1) and α-eleostearic acid methyl ester (2) with several olefins, including 1-hexene, dimethyl maleate and cis-stilbene as model compounds has been carried out using (1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene)-dichloro(o-isopropoxyphenylmethylene)ruthenium (Hoveyda-Grubbs 2nd generation, HG2) catalyst. The feasibility of these reactions is demonstrated by the observed high conversions and reasonable yields. Thus, regardless of the relatively low electron density, =CH–CH= conjugated units of molecules, including compound 2 as a sustainable, non-foodstuff source, can be utilized as building blocks for the synthesis of various value-added chemicals via olefin metathesis. DFT-studies and the product spectrum of the self-metathesis of 1,6-diphenyl-1,3,5-hexatriene suggest that a Ru η1-allylidene complex is the active species in the reaction.
- Kovács, Ervin,Sághy, Péter,Turczel, Gábor,Tóth, Imre,Lendvay, Gy?rgy,Domján, Attila,Anastas, Paul T.,Tuba, Róbert
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supporting information
p. 213 - 217
(2017/09/12)
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- A method for preparing methyl stearate
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The invention relates to the field of chemical synthesis, and discloses a preparation method of methyl stearate. By using concentrated sulfuric acid as a catalyst and carbon black as a wave-absorbing agent, stearic acid and absolute methanol are subjected to esterification reaction under the microwave radiation heating conditions to obtain the methyl stearate. The preparation method disclosed by the invention effectively shortens the esterification reaction time and enhances the reaction conversion rate.
- -
-
Paragraph 0029-0030
(2017/02/23)
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- Sulfonated porous organic polymer as a highly efficient catalyst for the synthesis of biodiesel at room temperature
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A new functionalized porous organic polymer bearing sulfonic acid groups (PDVTA-SO3H) at the pore surface with high surface area (SBET = 406 m2 g-1) and Bronsted acidity is reported. The material has been synthesized via post-synthetic sulfonation of the porous co-polymer poly-divinylbenzene-co-triallylamine (PDVTA-1) using chlorosulfonic acid as sulfonating agent. A detailed characterization of the -SO3H functionalized porous polymeric material has been carried out using N2 sorption, FT-IR and UV-vis spectroscopy, HR-TEM, FE-SEM, thermogravimetric and elemental analyses. Temperature programmed desorption of NH3 (TPD-NH3 analysis) of PDVTA-SO3H revealed a very high surface acidity of 2.3 mmol g-1. Such high acidity of PDVTA-SO3H has been explored to investigate its catalytic efficiency towards eco-friendly production of biodiesel via esterification of long-chain free fatty acids (FFA) to the respective fatty acid monoalkyl esters (FAMEs) at room temperature using methanol as reactant as well as solvent. The sulfonated porous polymer is found to be a very active and reusable solid acid catalyst giving high yields (～92-98%) of various biodiesel compounds under very mild reaction conditions.
- Gomes, Ruth,Bhanja, Piyali,Bhaumik, Asim
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p. 110 - 116
(2015/11/11)
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- A magnetically recoverable nanocatalyst based on functionalized mesoporous silica
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A magnetically separable 2D-hexagonally ordered thiol functionalized mesoporous silica material (Fe@TFMS) has been synthesized through co-condensation reaction of 3-mercaptopropyltriethoxysilane (MPTES) and tetraethylorthosilicate (TEOS) using cetyltrimethylammonium bromide (CTAB) as a cationic surfactant followed by immobilization of Fe3O4 nanocrystallies at the functionalized mesopore surface. Powder X-ray diffraction (XRD), N2 adsorption/desorption analysis, FT-IR, TEM, FE-SEM, TGA/DTA, CHNS, XPS and NH3-TPD tools are employed to characterize the materials. This functionalized mesoporous material exhibited high catalytic activity in the biodiesel production from a wide range of long chain fatty acids and soybean oil. The material showed high Lewis acidity of 1.02 mmolg-1 with a good Brunauer-Emmett-Teller (BET) surface area of 411 m2 g-1. Fe@TFMS exhibited excellent catalytic efficiency for this esterification reaction using methanol as a solvent cum reactant under eco-friendly and mild reaction conditions (room temperature, 25 °C).
- Bhanja, Piyali,Sen, Tapas,Bhaumik, Asim
-
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- Sterols and Fatty Acids of the Harmful Dinoflagellate Cochlodinium polykrikoides
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Sterol and fatty acid compositions were determined for Cochlodinium polykrikoides, a toxic, bloom-forming dinoflagellate of global significance. The major sterols were dinosterol (40% of total sterols), dihydrodinosterol (32%), and the rare 4α-methyl Δ8(14) sterol, amphisterol (23%). A minor sterol, 4α-methylergost-24(28)-enol was also detected (5.0%). The fatty acids had a high proportion of PUFAs (47%), consisting mainly of EPA (20%) and the relatively uncommon octadecapentaenoic acid (18: 5, 22%). While unlikely to be responsible for toxicity to fish, these lipids may contribute to the deleterious effects of this alga to invertebrates.
- Giner, José-Luis,Ceballos, Harriette,Tang, Ying-Zhong,Gobler, Christopher J.
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p. 249 - 252
(2016/02/27)
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- Esterification, transesterification and hydrogenation reactions of polyunsaturated compounds catalyzed by a recyclable polymer supported palladium catalyst
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Aliphatic and aromatic carboxylic acids were converted into their corresponding esters using a polymer supported palladium(II) β-ketoesterate complex under hydrogen atmosphere in the presence of catalytic bromobenzene in alcohols. This method was also applicable to the transesterification of esters. Good to excellent yields were obtained for different aliphatic or aromatic starting materials. The esterification (or transesterification) was promoted by the in situ generation of HBr from bromobenzene, which provided a mild acidic reaction environment. Pd(II) centers were converted into polymer stabilized metal nanoparticles (the true active species) under reaction conditions. The palladium catalyst exhibited a remarkable activity and was reusable for eight consecutive cycles. The present system was also tested for the preparation of partially hydrogenated fatty acid methyl esters, starting from a mixture composed by highly polyunsaturated esters and free carboxylic acids, taken as a model acidic feedstock for biodiesel upgrading.
- Dell'Anna, Maria Michela,Capodiferro, Vito Filippo,Mali, Matilda,Mastrorilli, Piero
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p. 106 - 114
(2016/07/06)
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- Sulfonic acid-functionalized periodic mesoporous organosilicas in esterification and selective acylation reactions
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The application of sulfonic acid-functionalized periodic mesoporous organosilicas (PMOs) having either phenyl (1a) or ethyl (1b) bridging groups was investigated in the esterification of a variety of alcohols and fatty acids. It was found that 1b consistently exhibited higher catalytic performance than 1a in the described reaction. In particular, it was proposed that the superior catalytic activity of 1b in esterification of fatty acids with methanol is a result of adequate hydrophobic-hydrophilic surface balance in the ethyl PMO catalyst. In addition, the study of chemoselective acylation of 1,3-butanediol with dodecanoic acid with varied mesoporous silica-supported solid sulfonic acids including both 1a and 1b implies that there is a compromise between the reaction selectivity and the surface physicochemical properties of the employed catalyst. Our results clearly show that the catalyst having high surface hydrophilic nature gives high selectivity toward the formation of mono-acylated products whereas those with relatively high hydrophobic characteristics showed enhanced selectivity toward the formation of di-acylated products.
- Karimi, Babak,Mirzaei, Hamid M.,Mobaraki, Akbar,Vali, Hojatollah
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p. 3624 - 3631
(2015/07/01)
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- A new hypercrosslinked supermicroporous polymer, with scope for sulfonation, and its catalytic potential for the efficient synthesis of biodiesel at room temperature
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We have designed a new hypercrosslinked supermicroporous polymer (HMP-1) with a BET surface area of 913 m2 g-1 by FeCl3via a catalyzed Friedel-Crafts alkylation reaction between carbazole and α,α′-dibromo-p-xylene. Upon sulfonation HMP-1 yielded a very efficient solid acid catalyst for the production of biodiesels via esterification/transesterification of free fatty acids (FFA)/esters at room temperature.
- Bhunia, Subhajit,Banerjee, Biplab,Bhaumik, Asim
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supporting information
p. 5020 - 5023
(2015/03/30)
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- Supported cobalt oxide nanoparticles as efficient catalyst in esterification and amidation reactions
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Co/SBA-15 nanoparticle catalysts (CoNP) were prepared using a commonly adapted synthetic route and then utilised for esterification and amidation reactions using aromatic and linear chain compounds for the production of long chain esters and amides. The study shows that the use of CoNP catalysts favours the use of aromatic reactants with electron donating substituents specifically in the para position. For the amidation reaction, good to excellent yields were obtained demonstrating tolerance towards differently substituted aromatic compounds. Overall, the synthesized catalysts proved to be efficient and highly versatile, and recyclable under the investigated conditions.
- Rajabi, Fatemeh,Raessi, Mojdeh,Arancon, Rick A.D.,Saidi, Mohammad Reza,Luque, Rafael
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p. 122 - 126
(2015/01/09)
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- A novel aromatic carbocation-based coupling reagent for esterification and amidation reactions
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A novel tropylium-based coupling reagent has been developed to facilitate the synthesis of a series of esters, amides, lactones and peptides under mild reaction conditions. Remarkably, this reagent can be used in catalytic amounts in conjunction with a sacrificial reagent, offering a new and efficient method for nucleophilic coupling reactions of carboxylic acids.
- Nguyen, Thanh V.,Lyons, Demelza J.M.
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supporting information
p. 3131 - 3134
(2015/06/17)
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- Antiproliferative activity of synthetic fatty acid amides from renewable resources
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In the work, the in vitro antiproliferative activity of a series of synthetic fatty acid amides were investigated in seven cancer cell lines. The study revealed that most of the compounds showed antiproliferative activity against tested tumor cell lines, mainly on human glioma cells (U251) and human ovarian cancer cells with a multiple drug-resistant phenotype (NCI-ADR/RES). In addition, the fatty methyl benzylamide derived from ricinoleic acid (with the fatty acid obtained from castor oil, a renewable resource) showed a high selectivity with potent growth inhibition and cell death for the glioma cell line - the most aggressive CNS cancer.
- Dos Santos, Daiane S.,Piovesan, Luciana A.,D'Oca, Caroline R. Montes,Hack, Carolina R. Lopes,Treptow, Tamara G.M.,Rodrigues, Marieli O.,Vendramini-Costa, Débora B.,Ruiz, Ana Lucia T.G.,De Carvalho, Jo?o Ernesto,D'Oca, Marcelo G. Montes
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p. 340 - 347
(2015/02/02)
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- Self-assembled sulfated zirconia nanocrystals with mesoscopic void space synthesized via ionic liquid as a porogen and its catalytic activity for the synthesis of biodiesels
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Abstract Self-assembled ZrO2 nanocrystals have been synthesized through a facile chemical route via steam-assisted ionothermal method using 1-butyl-3-methylimidazolium chloride ([bmim][Cl]) as a porogen. The template-free material has been sulphonated by 1(N) H2SO4 at room temperature followed by calcination in air at 723 K. Both ZrO2 and the sulfonated zirconia materials are thoroughly characterized by powder X-ray diffraction (PXRD), ultra high-resolution transmission electron microscopy (UHR-TEM), Fourier transform infrared spectroscopy (FT-IR), FE-SEM, N2 sorption, and NH3-TPD analyses. The sulfonated material has been employed as efficient and environmentally benign heterogeneous catalyst for the synthesis of biodiesels based on long chain fatty acid esters. The catalyst can be easily recovered and reused at least for five times without significant decrease in its catalytic activity.
- Banerjee, Biplab,Bhunia, Subhajit,Bhaumik, Asim
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p. 380 - 387
(2015/07/15)
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- Plasticizer and surfactant formation from food-waste- and algal biomass-derived lipids
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The potential of lipids derived from food-waste and algal biomass (produced from food-waste hydrolysate) for the formation of plasticizers and surfactants is investigated herein. Plasticizers were formed by epoxidation of double bonds of methylated unsaturated fatty acids with in situ generated peroxoformic acid. Assuming that all unsaturated fatty acids are convertible, 0.35 and 0.40 g of plasticizer can be obtained from 1 g of crude algae- or food-waste-derived lipids, respectively. Surfactants were formed by transesterification of saturated and epoxidized fatty acid methyl esters (FAMEs) with polyglycerol. The addition of polyglycerol would result in a complete conversion of saturated and epoxidized FAMEs to fatty acid polyglycerol esters. This study successfully demonstrates the conversion of food-waste into value-added chemicals using simple and conventional chemical reactions.
- Pleissner, Daniel,Lau, Kin Yan,Zhang, Chengwu,Lin, Carol Sze Ki
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p. 1686 - 1691
(2015/06/02)
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- Novel fatty acid analogues as human fatty acid synthase thioesterase domain inhibitors: Synthesis and their cytotoxicity screening
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A new class of 1, 3, 4-oxadiazoles substituted stearic/palmitic acid analogues were prepared. In-silico docking studies have been done into the crystal structure of thioesterase domain of human fatty acid synthase (2PX6) that gave some important structural information on the ligand binding interactions. The residues His 2481, Tyr 2462 & Ala 2448 formed hydrogen bonds with 1, 3, 4-oxadiazole ring. All the target compounds exhibited good binding interactions with the active site residues. Cytotoxicity has been done for some selected compounds against human lung carcinoma cell lines (A-549) by SRB method. The compounds showed strong cytotoxicity.
- Jubie, Selvaraj,Yadhav, Pawan Kumar,Chandrasekar, Moola Joghee Nanjan,Priya, Jeyapal Gomathi,Mvnl, Chaitanya,Dhanabal, Palanisamy
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p. 495 - 499
(2015/06/22)
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- Improved protocol toward 1,3,4-oxadiazole-2(3H)-thiones and scale-up synthesis in the presence of SDS as a micelle promoted catalyst
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Convenient procedure for in situ cyclization of hydrazinecarbodithioate potassium salts to 1,3,4-oxadiazole-2(3H)-thiones under normal phase micellar media catalysis promoted by sodium dodecyl sulfate (SDS) as an anionic surfactant is reported. The main advantage of this procedure is to provide shorter reaction time for the completion of cyclization; scale-up synthesis is possible and the oxadiazoles were obtained in high to excellent yields (87-100%), making the protocol an attractive alternative to the available methods.
- Yildirim, Ayhan
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p. 473 - 478
(2015/06/30)
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- Br?nsted acid surfactant-combined dicationic ionic liquids as green catalysts for biodiesel synthesis from free fatty acids and alcohols
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Quaternary ammonium Br?nsted acid surfactant-combined dicationic ionic liquids (BASDILs) based on zwitterionic 1,2-bis[N-methyl-N-(3-sulfopropyl)-alkylammonium]ethane betaines and various anions were prepared and characterized. BASDILs possess properties similar to those of phase-separated catalysts and were applied to the catalytic synthesis of biodiesel from free fatty acids and alcohols. Several factors were investigated and the results indicated that [C12Sb][p-CH3C6H4SO3] was the optimal catalyst, with good catalytic performance and reusability under mild conditions.
- Chang, Tao,He, Leqin,Zhang, Xiaojing,Yuan, Mingxia,Qin, Shenjun,Zhao, Jiquan
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p. 982 - 986
(2015/07/01)
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- GC-FID analysis of fatty acids and biological activity of Zanthoxylum rhetsa (Roxb.) DC seed oil
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The Fatty acid content and composition of fixed oil from Zanthoxylum rhetsa seeds was determined. The seeds were found to contain about ～19.5% of crude fixed oil on a dry weight basis. Fatty acids were converted into methyl esters and analyzed by GC-FID. Ten fatty acids were identified using GC-FID. The major monounsaturated and saturated fatty acids were oleic acid (41.6 - 43.5%) and palmitic acid (26.8-30.2%) respectively, whereas the α-linolenic acid (12.1 - 12.5%) and linoleic acid (10.0%) were polyunsaturated fatty acid. Stearic acid (5.2 - 6.0%), myristic acid (0.1%), traces of pentadecanoic, heptadecanoic and arachidic acid were also identified. These fatty acids have not been reported earlier from the oil of Z. rhetsa. Fixed oil exhibited significant free radical scavenging activity which was measured using DPPH, and is also known to inhibit the gastrointestinal motility significantly.
- Naik, Rajashri R.
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p. 1929 - 1935
(2016/02/27)
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