Journal articles: 'Esterification Reactivity'

1

Zhan, Shaoqi, Xiaochun Tao, Liangzhen Cai, Xiaohui Liu, and Taoping Liu. "The carbon material functionalized with NH2+ and SO3H groups catalyzed esterification with high activity and selectivity." Green Chem. 16, no. 11 (2014): 4649–53. http://dx.doi.org/10.1039/c4gc01395f.

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Mei, Sheng-Fu, Jin Liu, Zhen Li, Yan Chen, and Jing Zhang. "Reactivity of 2-Phosphonobutane-1,2,4-tricarboxylic Acid Esterification." Asian Journal of Chemistry 26, no. 5 (2014): 1530–32. http://dx.doi.org/10.14233/ajchem.2014.17279.

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3

Li, Chong, Yueping Jiang, Baoshan Huang, Menghang Zhang, Yanhong Feng, and Zhitao Yang. "Preparation and Properties of Jute Fiber Long-Chain Fatty Acid Esters in Supercritical Carbon Dioxide." Materials 12, no. 9 (May 8, 2019): 1499. http://dx.doi.org/10.3390/ma12091499.

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A two-step method involving continuous screw-extrusion steam explosion (CSESE) pretreatment and esterification in supercritical carbon dioxide (scCO2) is used to prepare long-chain fatty acid-modified jute fiber. The weight gain percentage (WG %) of CSESE-pretreated jute laurate (JL) was 110.7% when esterification was carried out in scCO2 at 14 MPa and 100 °C for 2 h. The corresponding WG % was 105.5% when esterification was instead carried out in pyridine at 100 °C for 2 h. Scanning electron microscopy and X-ray diffraction indicated that CSESE pretreatment enhanced the reactivity of jute fiber, with esterification in scCO2 simultaneously occurring on the fibers surface and internal walls. The glass transition temperature of esterified jute was approximately 119 °C, indicating that it could be hot processed over a wide temperature range. The esterified jute had an oil absorption ratio of 17.01 g/g, so it can be used as an oil absorption material.

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Roswanda, Robby, Ilham Ardatul Putra, Maria Mardiastuti, and Didin Mujahidin. "Catalyst Free Hydroxyl Protection of Quinine via Esterification." Key Engineering Materials 811 (July 2019): 3–7. http://dx.doi.org/10.4028/www.scientific.net/kem.811.3.

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A method to protect the hydroxyl group of quinine via esterification is developed. The method uses acetyl and benzoyl as the protection group. The method employs no catalyst that generates reasonable yield at 83% for acetyl and 73% for benzoyl. This catalyst free method emphasizes on the importance substrate reactivity to achieve free catalyst procedure. Ester form of quinine synthesized might be further functionalized for various aims in accordance to its rich functional group and building block of quinine.

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Kastratović, Vlatko, Milica Radulović, and Kristina Kastratović. "Esterification of propanoic acid in the presence of a homogeneous catalyst." Kragujevac Journal of Science, no. 44 (2022): 45–55. http://dx.doi.org/10.5937/kgjsci2244045k.

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Esters are organic compounds that are widely used even on an industrial scale, so their production has been extensively investigated. The aim of this work is to carry out the optimization process of esterification of propionic acid with lower monohydric alcohols. The influence of the amount of catalyst (H2SO4), the size and structure of the alcohol, the influence of the a-substituent, the molar acid/alcohol ratio and temperature on the esterification process were investigated. The descending order of reactivity tested alcohol is: 1-butanol> 1-propanol> ethanol> 2-propanol. As the acid/alcohol molar ratio increases, the rate and yield of the esterification reaction increase. The maximum yield of n-propyl propanoate in our experiments was 96.9%, achieved at a molar ratio of propanoic acid/1-propanol/catalyst 1/10/0.20 and a temperature of 65°C for 210 minutes of reaction.

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6

Vázquez, Ester, and Maurizio Prato. "Functionalization of carbon nanotubes for applications in materials science and nanomedicine." Pure and Applied Chemistry 82, no. 4 (March 13, 2010): 853–61. http://dx.doi.org/10.1351/pac-con-09-10-40.

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Carbon nanotubes (CNTs) can be functionalized using a variety of efficient protocols. Especially, esterification and amidation reactions are exploited along with 1,3-dipolar cycloadditions. The use of microwaves (MWs) to activate the reactivity of CNTs is also reported. Innovative NMR methodologies can be introduced to investigate the covalent attachment of organic moieties to CNTs.

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7

Wu, Yan, Shiang He, Dongmei Li, Yang Li, and Hao Wang. "Esterification of naphthenic acids with various structures over tungstophosphoric acid-intercalated layer double hydroxide catalysts with various interlayer spacings." Clay Minerals 56, no. 3 (September 2021): 250–59. http://dx.doi.org/10.1180/clm.2022.3.

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AbstractTungstophosphoric acid-intercalated MgAl layer double hydroxides (LDHs) are active catalysts for removing naphthenic acids (NAs) from petroleum via esterification. Due to their active sites being in the interlayer, the interlayer spacing of LDHs might affect their activity, particularly for NAs with various structures. Herein, two tungstophosphoric acid-intercalated MgAl LDHs with various interlayer spacings (d003 = 1.46 and 1.07 nm) synthesized by varying the ion-exchange time were used as catalysts for esterification between NAs and ethylene glycol. Six NAs with various side chains and rings were used as model compounds to investigate the effects of NA structures and d003 values on the activity of LDHs. In general, NAs with large molecule sizes and steric hindrances are less reactive over the same catalyst. The LDH with a larger d003 value favours the esterification of NAs regardless of their structure, particularly NAs with large molecule sizes and steric hindrances. However, a large d003 is less effective for esterification of NAs with conjugated carboxyl groups. An enlarged interlayer space might facilitate NA molecules to access the interlayer of LDHs so as to come into contact with the catalytic sites, making this process responsible for the enhanced reactivity. The esterification kinetics of cyclohexanecarboxylic acid over these LDHs follow a first-order reaction. The activation energies for the LDHs with large and small d003 values are 26.25 and 32.18 kJ mol–1, respectively.

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8

Kastratovic, Vlatko, and Miljan Bigovic. "Esterification of stearic acid with lower monohydroxylic alcohols." Chemical Industry and Chemical Engineering Quarterly 24, no. 3 (2018): 283–91. http://dx.doi.org/10.2298/ciceq170327040k.

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Esters play a significant role in everyday life but also in the chemical industry. The aim of this study is to investigate the influence of different parameters on the process of esterification of higher monocarboxylic acids with lower monohydroxylic alcohols. We examined the influences of the following variables: the type and amount of the catalyst, the structure of alcohols and fatty acids, the acid/alcohol molar ratio, and the temperature of the esterification process. The descending order of reactivity found alcohols is: 1-butanol > 1-propanol > 2-methyl-1-propanol > ethanol > 2-butanol >2-propanol > 2-methyl-2-propanol. The results of this study show no significant effect of chain lengths of saturated fatty acids on the speed and yield of esterification. The presence of the double bond in unsaturated fatty acids reduces the acid to ester conversion. The highest yield (99%) was obtained in the reaction of stearic acid and 1-butanol with an acid/alcohol/catalyst (H2SO4) mole ratio 1/15/0.75 and at a temperature of 65?C.

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9

Breitenlechner, Stefan, and Thorsten Bach. "Kinetic Study on the Esterification of Hexanoic Acid with N,N-Dialkylamino Alcohols: Evidence for an Activation by Hydrogen Bonding." Zeitschrift für Naturforschung B 61, no. 5 (May 1, 2006): 583–88. http://dx.doi.org/10.1515/znb-2006-0513.

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The pseudo-first order rate constant for the esterification of hexanoic acid (1) and five different N,N-dialkylamino alcohols (2) was determined in comparison to 1-hexanol (k = 0.67 · 10−5 s−1). The values range from 0.60 · 10−5 s−1 to 9.3 · 10−5 s−1. The data suggest a differing reactivity for structurally related compounds, which is directly correlated to the ability of the corresponding amino alcohol to activate the carboxylic acid by hydrogen bonding. A seven-membered transition state C≠ is postulated for reactions of 2-amino alcohols. The fastest reaction was observed for trans-2-(N,N-dimethylamino) cyclohexanol (2e), in which the amino and the hydroxyl groups are in an almost perfect synperiplanar 1,2-position. Attempts to further enhance the rate of the esterification by the addition of potential catalysts failed. Only Cu(OTf)2 (2.5 mol-%) allowed for a moderate rate increase from 7.5 · 10−5 s−1 (uncatalyzed) to 14.8 · 10−5 s−1 (catalyzed) in the esterification of hexanoic acid (1) with 2-(N,N-dimethylamino)ethanol (2a).

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10

Rabee, Abdallah, Gamal Mekhemer, Amin Osatiashtiani, Mark Isaacs, Adam Lee, Karen Wilson, and Mohamed Zaki. "Acidity-Reactivity Relationships in Catalytic Esterification over Ammonium Sulfate-Derived Sulfated Zirconia." Catalysts 7, no. 7 (July 5, 2017): 204. http://dx.doi.org/10.3390/catal7070204.

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11

Nishio, Yuya, Akari Kawazu, Shun Hirano, and Hiroshi Matsubara. "Preparation of fluorous Yamaguchi reagents and evaluation of their reactivity in esterification." Tetrahedron 72, no. 5 (February 2016): 720–25. http://dx.doi.org/10.1016/j.tet.2015.12.026.

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12

Ershov, B. G., V. B. Komarov, S. A. Kulyukhin, A. E. Seliverstov, and V. N. Bondareva. "Study of the effect of γ-irradiation of industrial grade cellulose on the products of its esterification." Industrial laboratory. Diagnostics of materials 88, no. 12 (December 25, 2022): 28–35. http://dx.doi.org/10.26896/1028-6861-2022-88-12-28-35.

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Treatment of cellulose with ionizing radiation (γ-rays, accelerated electrons) provides the possibility to reduce its molecular weight, change the molecular weight distribution, increase the esterification reactivity and affect other physical and chemical characteristics. The acquired properties, in turn, make it possible to obtain then esters with the desired characteristics. We present the results of studying the effect of γ-irradiation of industrial grades of cellulose on the esterification products, i.e., lacquer colloxylins and xanthogenates. It is found that γ-irradiation at a dose of 3 - 5 kGy prior to mercerization leads to an increase in the reactivity of the polymer in the reaction of xanthogenation by more than 30%. Nitro derivatives corresponding to the technical characteristics (conditional viscosity and nitrogen content) of colloxylins of different grades were obtained by irradiation at a dose of 20 and 30 kGy. It is shown that the stages of prehydrolysis and reduction of nitrocellulose viscosity during its treatment in autoclaves can be excluded when producing colloxylins. It appeared possible to reduce significantly the consumption of carbon disulfide in the technology of xanthocarbon production. The results obtained can be used in developing optimal modes and performance criteria for radiation pretreatment of cellulose of different grades during nitration and xanthogenation proceeding from changes in their physical and chemical properties upon γ-irradiation.

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13

Cheng, Yu He, Biao Zhang, Shang Jiang Dai, Han Lin Tong, and Li Xia Li. "Reusable and Efficient Polystryrene-Supported Acidic Ionic Liquid Catalyst for the Synthesis of n-Butyl Acetate." Advanced Materials Research 983 (June 2014): 20–25. http://dx.doi.org/10.4028/www.scientific.net/amr.983.20.

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A series of polystyrene-supported 1-(propyl-3-sulfonate)-3-methy-imidazolium hydrosulfate acidic ionic liquid (PS-[SO3H-PMIM][HSO4]) catalysts with different [SO3H-PMIM][HSO4] contents were prepared and tested for esterification of n-butyl alcohol with acetic acid. It was found that the reactivity of the catalyst increased with increasing [SO3H-PMIM][HSO4] content, and best yield of n-Butyl acetate of 98% was obtained using PS-[SO3H-PMIM][HSO4]1 within 1.5h. The catalytic activity of this catalyst decreased slightly after fifth using.

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14

Chen, Yaoyao, Chengliang Li, Yongmei Cui, Mingming Sun, Xueshun Jia, and Jian Li. "Bu4NI-Catalyzed C–C Bond Cleavage and Oxidative Esteriﬁcation of Allyl Alcohols with Toluene Derivatives." Synthesis 51, no. 19 (July 16, 2019): 3667–74. http://dx.doi.org/10.1055/s-0039-1690105.

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A novel oxidative esterification of 1-arylprop-2-en-1-ols with toluene derivatives catalyzed by tetrabutylammonium iodide (TBAI) is reported. The optimization of the reaction conditions illustrates that each of experiment parameters including the catalyst, solvent, and oxidant is significant for present oxidative functionalization. This metal-free protocol has a broad substrate scope including the halogen groups for further functionalization and enriches the reactivity profile of allyl alcohol and toluene derivatives. In addition, this protocol represents a new transformation of allyl alcohol involving C–C bond cleavage and C–O bond forming.

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15

Hughes, David L., and Robert A. Reamer. "The Effect of Acid Strength on the Mitsunobu Esterification Reaction: Carboxyl vs Hydroxyl Reactivity." Journal of Organic Chemistry 61, no. 9 (January 1996): 2967–71. http://dx.doi.org/10.1021/jo952180e.

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16

Kubyshkin, Vladimir, and Nediljko Budisa. "Hydrolysis, polarity, and conformational impact of C-terminal partially fluorinated ethyl esters in peptide models." Beilstein Journal of Organic Chemistry 13 (November 16, 2017): 2442–57. http://dx.doi.org/10.3762/bjoc.13.241.

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Fluorinated moieties are highly valuable to chemists due to the sensitive NMR detectability of the 19F nucleus. Fluorination of molecular scaffolds can also selectively influence a molecule’s polarity, conformational preferences and chemical reactivity, properties that can be exploited for various chemical applications. A powerful route for incorporating fluorine atoms in biomolecules is last-stage fluorination of peptide scaffolds. One of these methods involves esterification of the C-terminus of peptides using a diazomethane species. Here, we provide an investigation of the physicochemical consequences of peptide esterification with partially fluorinated ethyl groups. Derivatives of N-acetylproline are used to model the effects of fluorination on the lipophilicity, hydrolytic stability and on conformational properties. The conformational impact of the 2,2-difluoromethyl ester on several neutral and charged oligopeptides was also investigated. Our results demonstrate that partially fluorinated esters undergo variable hydrolysis in biologically relevant buffers. The hydrolytic stability can be tailored over a broad pH range by varying the number of fluorine atoms in the ester moiety or by introducing adjacent charges in the peptide sequence.

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17

Adjaoud, Antoine, Reiner Dieden, and Pierre Verge. "Sustainable Esterification of a Soda Lignin with Phloretic Acid." Polymers 13, no. 4 (February 21, 2021): 637. http://dx.doi.org/10.3390/polym13040637.

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In this work, a sustainable chemical process was developed through the Fischer esterification of Protobind® lignin, a wheat straw soda lignin, and phloretic acid, a naturally occurring phenolic acid. It aimed at increasing the reactivity of lignin by enhancing the number of unsubstituted phenolic groups via a green and solvent-free chemical pathway. The structural features of the technical and esterified lignins were characterized by complementary spectroscopic techniques, including 1H, 13C, 31P, and two-dimensional analysis. A substantial increase in p-hydroxyphenyl units was measured (+64%, corresponding to an increase of +1.3 mmol g−1). A full factorial design of the experiment was employed to quantify the impact of critical variables on the conversion yield. The subsequent statistical analysis suggested that the initial molar ratio between the two precursors was the factor predominating the yield of the reaction. Hansen solubility parameters of both the technical and esterified lignins were determined by solubility assays in multiple solvents, evidencing their high solubility in common organic solvents. The esterified lignin demonstrated a better thermal stability as the onset of thermal degradation shifted from 157 to 220 °C, concomitantly to the shift of the glass transition from 92 to 112 °C. In conclusion, the esterified lignin showed potential for being used as sustainable building blocks for composite and thermoset applications.

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Echeverri, Marcelo, Amparo Alvarez-Valdés, Francisco Navas, Josefina Perles, Isabel Sánchez-Pérez, and A. G. Quiroga. "Using phosphine ligands with a biological role to modulate reactivity in novel platinum complexes." Royal Society Open Science 5, no. 2 (February 2018): 171340. http://dx.doi.org/10.1098/rsos.171340.

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Three platinum complexes with cis and trans configuration cis -[Pt(TCEP) 2 Cl 2 ], cis -[Pt(tmTCEP) 2 Cl 2 ] and trans -[Pt(TCEP) 2 Cl 2 ], where TCEP is tris(2-carboxyethyl)phosphine, have been synthesized and fully characterized by usual techniques including single-crystal X-ray diffraction for trans -[Pt(TCEP) 2 Cl 2 ] and cis -[Pt(tmTCEP) 2 Cl 2 ]. Here, we also report on an esterification process of TCEP, which takes place in the presence of alcohols, leading to a platinum complex coordinated to an ester tmTCEP (2-methoxycarbonylethyl phosphine) ligand. The stability in solution of the three compounds and their interaction with biological models such as DNA (pBR322 and calf thymus DNA) and proteins (lysozyme and RNase) have also been studied.

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19

Huang, Chien-Chang, Shih-Han Ho, Jo-Shu Chang, and Pei-Jyuan Gao. "A sulfated/chlorinated Sr–Fe composite oxide as a novel solid and reusable superacid catalyst for oleic acid esterification." New Journal of Chemistry 44, no. 32 (2020): 13669–84. http://dx.doi.org/10.1039/d0nj00525h.

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The high catalytic reactivity and reusability of the sulfated/chlorinated Sr–Fe oxide could be ascribed to the synergistic effect of coordinated Cl⁻ and surface SrSO₄ clusters on suppressing the chemisorption of oleic acid on the surface cations.

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20

Samateh, Malick, Siddharth Marwaha, Jose K. James, Vikas Nanda, and George John. "Sucralose hydrogels: Peering into the reactivity of sucralose versus sucrose under lipase catalyzed trans-esterification." Carbohydrate Research 521 (November 2022): 108647. http://dx.doi.org/10.1016/j.carres.2022.108647.

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21

Montenegro Hernández, Alejandra, and Jorge Enrique Rodríguez Páez. "Synthesising highly reactive tin oxide using Tin(II)2- ethylhexanoate polynucleation as precursor." Ingeniería e Investigación 29, no. 1 (January 1, 2009): 47–52. http://dx.doi.org/10.15446/ing.investig.v29n1.15142.

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Tin oxide is a widely used compound in technological applications, particularity as a catalyst, gas sensor and in making varistors, transparent conductors, electrocatalytic electrodes and photovoltaic cells. An ethylhexanoate tin salt, a carboxylic acid and poly esterification were used for synthesising highly reactive tin oxide in the present study. Synthesis was controlled by Fourier transform infrared (FTIR) spectroscopy and recording changes in viscosity. The tin oxide characteristics so obtained were determined using FTIR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The SnO2 dust synthesised and heat-treated at 550°C yielded high density aggregates, having greater than 50 μm particle size. This result demonstrates the high reactivity of the ceramic powders synthesised here.

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22

Dong, Ben, Jiasheng Qian, Mingjie Li, Zheng-Jun Wang, Minyan Wang, Dingyi Wang, Chengkai Yuan, Ying Han, Yue Zhao, and Zhuangzhi Shi. "External oxidant-compatible phosphorus(III)-directed site-selective C–H carbonylation." Science Advances 6, no. 51 (December 2020): eabd1378. http://dx.doi.org/10.1126/sciadv.abd1378.

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The first development of an external oxidant-compatible system involving a phosphorus(III)-directed C–H functionalization has been uncovered. An efficient C–H esterification of indoles with CO and alcohols has been reported in which the high reactivity and the exclusive C7-selectivity derives from the selection of a P(III)–directing group and the utilization of benzoquinone as an external oxidant with palladium catalysis. This strategy shows many advantages, involving an easily accessible and removable directing group, the use of cheap carbonylation sources, a broad substrate scope, and excellent positional selectivity. Two cyclopalladated intermediates were confirmed by x-ray analysis, uncovering key mechanistic features of this P(III)-directed C–H metalation event.

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23

Heller, Stephen T., and Richmond Sarpong. "On the reactivity of imidazole carbamates and ureas and their use as esterification and amidation reagents." Tetrahedron 67, no. 46 (November 2011): 8851–59. http://dx.doi.org/10.1016/j.tet.2011.09.057.

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24

Yujaroen, Duangkamol, Motonobu Goto, Mitsuru Sasaki, and Artiwan Shotipruk. "Esterification of palm fatty acid distillate (PFAD) in supercritical methanol: Effect of hydrolysis on reaction reactivity." Fuel 88, no. 10 (October 2009): 2011–16. http://dx.doi.org/10.1016/j.fuel.2009.02.040.

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25

Ghesti, Grace Ferreira, Julio Lemos de Macedo, Vicente Cavalcanti Ibiapina Parente, José Alves Dias, and Sílvia Cláudia Loureiro Dias. "Synthesis, characterization and reactivity of Lewis acid/surfactant cerium trisdodecylsulfate catalyst for transesterification and esterification reactions." Applied Catalysis A: General 355, no. 1-2 (February 2009): 139–47. http://dx.doi.org/10.1016/j.apcata.2008.12.008.

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26

Nguyen, Dang T., and Quan T. Pham. "A Theoretical and Experimental Study on Esterification of Citric Acid with the Primary Alcohols and the Hydroxyl Groups of Cellulose Chain (n = 1-2) in Parched Condition." Journal of Chemistry 2020 (November 12, 2020): 1–9. http://dx.doi.org/10.1155/2020/8825456.

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Esterification of citric acid (CA) with the primary alcohols and the hydroxyl groups of cellulose chain (n = 1-2) in parched condition were investigated by using density functional theory (DFT) method and a two-layer ONIOM approach. Geometry and energy of reactants, products, and transition state (TS) structures were optimized at B3LYP/6-311g (d, p) level and ONIOM (B3LYP/6-311g (d, p):PM3MM) level. The computational results show that the esterification occurs in the two main steps: the first step is the dehydration reaction of CA to form anhydrides of 5-membered ring and 6-membered ring and the second step is the ring opening reaction with the hydroxyl –OH groups to form the ester products. The energy barrier of dehydration reaction step is much higher than that of ring opening reaction step. Effect of substituent R in primary alcohol R-CH2OH (R: CH=CH2, CH2NHCH3, CH2OCH3, CH2Cl) and cellulose chain (1G, 2G) on the reactivity, which has negative inductive effect –I, is significant. The combination of calculation data and experiment data were applied to make findings more rigorous. The activation energy of CA was determined by using differential scanning calorimetry (DSC) and thermal gravimetric (TG) analysis to be E a exp = 47.8 kcal/mol; the experimental data favoured the dehydration reaction step of CA.

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Tabas, I., S. J. Feinmark, and N. Beatini. "The reactivity of desmosterol and other shellfish- and xanthomatosis-associated sterols in the macrophage sterol esterification reaction." Journal of Clinical Investigation 84, no. 6 (December 1, 1989): 1713–21. http://dx.doi.org/10.1172/jci114354.

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Juan, Joon Ching, Jingchang Zhang, and Mohd Ambar Yarmo. "Structure and reactivity of silica-supported zirconium sulfate for esterification of fatty acid under solvent-free condition." Applied Catalysis A: General 332, no. 2 (November 2007): 209–15. http://dx.doi.org/10.1016/j.apcata.2007.08.016.

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Patil, Meghshyam K., and Sharekh Shaikh. "Nano-Sized and -Crystalline Sulfated Zirconia Solid Acid Catalysts for Organic Synthesis." Materials Science Forum 757 (May 2013): 69–83. http://dx.doi.org/10.4028/www.scientific.net/msf.757.69.

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Sulfated Zirconia (SZ) has opened up a very interesting area for application predominantly as catalyst for various acid catalyzed organic syntheses and transformation reactions. Catalytic properties of SZ vary with methods of preparation. Lot of efforts is made to modify SZ to increase reactivity and stability of the catalyst. This review focuses on the individual synthesis routes to prepare nano-sized and –crystalline SZ, short discussion on its characterization and exhaustive survey on its utility in organic chemistry for the development of new synthetic methodologies, which provide simple direction having enormous practical significance. As can be realized, the nano-sized and –crystalline SZ as solid acid catalyst exhibits exceptionally better catalytic activity and selectivity for the synthesis of trisubstituted and tetrasubstituted imidazoles, acetyl salicylic acid, dypnone, esterification of acetic acid, caprylic acid and so on.

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Wang, Lu-Cun, C. M. Friend, Rebecca Fushimi, and Robert J. Madix. "Active site densities, oxygen activation and adsorbed reactive oxygen in alcohol activation on npAu catalysts." Faraday Discussions 188 (2016): 57–67. http://dx.doi.org/10.1039/c5fd00161g.

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The activation of molecular O₂ as well as the reactivity of adsorbed oxygen species is of central importance in aerobic selective oxidation chemistry on Au-based catalysts. Herein, we address the issue of O₂ activation on unsupported nanoporous gold (npAu) catalysts by applying a transient pressure technique, a temporal analysis of products (TAP) reactor, to measure the saturation coverage of atomic oxygen, its collisional dissociation probability, the activation barrier for O₂ dissociation, and the facility with which adsorbed O species activate methanol, the initial step in the catalytic cycle of esterification. The results from these experiments indicate that molecular O₂ dissociation is associated with surface silver, that the density of reactive sites is quite low, that adsorbed oxygen atoms do not spill over from the sites of activation onto the surrounding surface, and that methanol reacts quite facilely with the adsorbed oxygen atoms. In addition, the O species from O₂ dissociation exhibits reactivity for the selective oxidation of methanol but not for CO. The TAP experiments also revealed that the surface of the npAu catalyst is saturated with adsorbed O under steady state reaction conditions, at least for the pulse reaction.

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31

Zahalka, Hayder A., and Yoel Sasson. "Esterification of 1,4-dichlorobutane with sodium formate under solid–liquid phase transfer catalysis. A kinetic study." Canadian Journal of Chemistry 67, no. 2 (February 1, 1989): 245–49. http://dx.doi.org/10.1139/v89-040.

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Kinetic data are reported regarding the esterification of 1,4-dichlorobutane with sodium formate catalyzed by quaternary ammonium salts as a model for reactions in series, under solid–liquid phase transfer conditions. The process was found to follow a consecutive first-order mechanism of the general type A → R → S. The reactivity of the quaternary ammonium salts with regard to the counteranion was Cl− > Br− > 1− > HSO4−. The reaction rate was linearly dependent on catalyst concentration up to 12 mol% of catalyst relative to the substrate. Above this concentration the rate was constant and independent of the amount of the catalyst. The activation energy of the two consecutive steps was found to be similar (21 kcal/mol). Therefore, the product distribution (R/S) is not appreciably affected by temperature. A mechanism termed "Thin aqueous boundary layer" is suggested for nucleophilic displacement reactions under solid–liquid phase transfer conditions. Keywords: phase transfer catalysis, series reactions, kinetic study.

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32

Jansen, Jacob H., Adam B. Powell, Sarah E. Specht, Selim Gerislioglu, and Ive Hermans. "Understanding the Structure and Reactivity of Mixed Titanium(IV) Alkoxide and Tin(II)/(IV) Carboxylates as Esterification Catalysts." ACS Sustainable Chemistry & Engineering 10, no. 7 (February 1, 2022): 2484–93. http://dx.doi.org/10.1021/acssuschemeng.1c07633.

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33

Thévenet, Sophie, Angelika Wernicke, Stanislaw Belniak, Gérard Descotes, Alain Bouchu, and Yves Queneau. "Esterification of unprotected sucrose with acid chlorides in aqueous medium: kinetic reactivity versus acyl- or alkyloxycarbonyl-group migrations." Carbohydrate Research 318, no. 1-4 (May 1999): 52–66. http://dx.doi.org/10.1016/s0008-6215(99)00079-8.

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34

Joelianingsih, Armansyah H. Tambunan, and Hiroshi Nabetani. "Reactivity of Palm Fatty Acids for the Non-catalytic Esterification in a Bubble Column Reactor at Atmospheric Pressure." Procedia Chemistry 9 (2014): 182–93. http://dx.doi.org/10.1016/j.proche.2014.05.022.

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35

Basiuk, Vladimir A. "Reactivity of Carboxylic Groups on Armchair and Zigzag Carbon Nanotube Tips: A Theoretical Study of Esterification with Methanol." Nano Letters 2, no. 8 (August 2002): 835–39. http://dx.doi.org/10.1021/nl025607n.

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Heller, Stephen T., and Richmond Sarpong. "ChemInform Abstract: On the Reactivity of Imidazole Carbamates and Ureas and Their Use as Esterification and Amidation Reagents." ChemInform 43, no. 13 (March 1, 2012): no. http://dx.doi.org/10.1002/chin.201213060.

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37

Zoubir, Mohammed, Abdellah Zeroual, Mohammed El Idrissi, Fatima Bkiri, Ahmed Benharref, Noureddine Mazoir, and Abdeslam El Hajbi. "Experimental and theoretical analysis of the reactivity and regioselectivity in esterification reactions of diterpenes (totaradiol, totaratriol, hinikione and totarolone)." Mediterranean Journal of Chemistry 6, no. 4 (April 9, 2017): 98–107. http://dx.doi.org/10.13171/mjc64/01704101226-zeroual.

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Six esters have been synthesized in the acetylation, benzoylation and Baeyer-Villiger oxidation of starting materials totaradiol 1, totaratriol 2, hinikione 7 and totarolone 8. A complete theoretical study of the reaction has been carried out including highly regioselectivity induction experiments and using density functional methods B3LYP/6-31G(d). The analysis of the nucleophilic Parr functions P - k and the electrostatic potential in diterpenes 1 and 2 offered an explanation of the regioselectivity found in these reactions and in Baeyer-Villiger reaction we use transition state theory and the electrostatic potential to understand the high regioselectevity observed, we found that the regioselectivity is kinetically and thermodynamically favorable and the electronic density is located in the multi-substituted carbon.

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38

Asensio, Gregorio, Cecilia Andreu, and J. Alberto Marco. "Influence of structural factors and enzyme type on the reactivity and enantioselectivity of the enzymatic esterification of bicyclicmeso dialcohols." Chemische Berichte 125, no. 10 (October 1992): 2233–38. http://dx.doi.org/10.1002/cber.19921251010.

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39

Rajabi, Fatemeh, Chin Hua Chia, Mika Sillanpää, Leonid G. Voskressensky, and Rafael Luque. "Cytosine Palladium Complex Supported on Ordered Mesoporous Silica as Highly Efficient and Reusable Nanocatalyst for One-Pot Oxidative Esterification of Aldehydes." Catalysts 11, no. 12 (December 3, 2021): 1482. http://dx.doi.org/10.3390/catal11121482.

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The synthesis of esters is one of the most fundamental and significant subjects in organic chemistry and chemical industry because they are used in high-value products such as cosmetics, biofuel, pharmaceuticals, surfactants, and food ingredients. In this study, an efficient, economic, sustainable, and green protocol for oxidative esterification reaction has been developed. A one-pot direct transformation of aliphatic, aromatic, and unsaturated aldehydes into esters in the presence of oxygen has been carried out over mesoporous organosilica-supported palladium nanocatalyst (Pd-Cyt@SBA-15) under ambient conditions. Pd-Cyt@SBA-15 efficiently catalyzed selectively large-scale conversion of aldehydes into esters in high yields and large turnover numbers (TON = 98,000). Pd-Cyt@SBA-15 nanocatalyst demonstrated excellent reusability and stability and could be recycled up to ten times without loss of significant reactivity. ICP-AES analysis showed that no leaching of active palladium species occurred during the recycling process of the heterogeneous Pd-Cyt@SBA-15 nanocatalyst.

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Suota, Maria Juliane, Débora Merediane Kochepka, Marlon Gualberto Ganter Moura, Cleverton Luiz Pirich, Mailson Matos, Washington Luiz Esteves Magalhães, and Luiz Pereira Ramos. "Lignin functionalization strategies and the potential applications of its derivatives – A Review." BioResources 16, no. 3 (July 12, 2021): 6471–511. http://dx.doi.org/10.15376/biores.16.3.suota.

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Lignin is one of the most important and widespread carbon sources on Earth. Significant amounts of lignin are delivered to the market by pulp mills and biorefineries, and there have been many efforts to develop routes for its valorization. Over the years, lignin has been used to produce biobased chemicals, materials, and advanced biofuels on the basis of its variable functionalities and physicochemical properties. Today, lignin’s applications are still limited by its heterogeneity, variability, and low reactivity. Thus, modification technologies have been developed to allow lignin to be suitable for a wider range of attractive industrial applications. The most common modifications used for this purpose include amination, methylation, demethylation, phenolation, sulfomethylation, oxyalkylation, acylation or esterification, epoxidation, phosphorylation, nitration, and sulfonation. This article reviews the chemistry involved in these lignin modification technologies, discussing their effect on the finished product while presenting some market perspectives and future outlook to utilize lignin in sustainable biorefineries.

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Athmani, Hamza, and Nourreedine Benali-Cherif. "Structure and thermal analysis of amino acids." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C989. http://dx.doi.org/10.1107/s205327331409010x.

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The twenty amino acids are chemical compounds having two functional groups (carboxyl:-COOH, amine:-NH2) and an asymmetric carbon (except glycine). They are amphoteric and can exist as zwitterion. Because of the reactivity of amino acids (esterification, amidation, N-alkylisation, N-arylation, protonation), and their conformation (aliphatic, aromatic) chemical, properties (acid, base, and / or hydroxylated, solubility), and physical properties (absorbance, NLO), our laboratory contribute to the study (synthesis and X ray single crystal structures) of new organic-inorganic hybrid compounds which allows to the development of materials with novel properties [1-3]. Our work is also based on the relationship between the thermal decomposition of amino acids and their chemical structures, dozens compounds were selected and the results of the DTA, TG and DTG thermal decomposition was performed by several methods. Diffraction results are used for the identification of degradation mechanisms of the chemical structure, the stability of the compound studied and the anticipation of possible syntheses of hybrid compounds.

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Xue, Su Ling. "Study on the Properties of Thermoplastic Resin-Based Carbon Fiber Composites Based on the Wrapping Method in the Art Design of Seating." Key Engineering Materials 852 (July 2020): 98–108. http://dx.doi.org/10.4028/www.scientific.net/kem.852.98.

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The diglyceryl phthalate epoxy resin contains a benzene ring in its molecular structure, and its molecular weight is small. In addition to the generality of epoxy resins, it also has the advantages of low viscosity, moderate reactivity, high adhesion, good compatibility, excellent electrical insulation and ultra-low temperature, and good weather resistance. It has good adhesion with carbon fiber, and it is suitable to make carbon fiber composite material. Based on this background, this article mainly focuses on the seat art design, and uses the wrapping method to analyze the preparation of the carbon fiber composite resin matrix. The optimal reaction conditions are determined by changing the reaction during the preparation of the thermoplastic resin matrix. / PA = 1.9, esterification time 120min, cyclization time 70min, reaction temperature 110 °C, amount of promoter water 6g, concentration of cyclizing agent sodium hydroxide solution 30%. The resin synthesized in this case is a light-yellow transparent liquid with an epoxy value of 0.51 (mol / 100g).

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Shiryaeva, A. D., S. V. Moiseeva, S. V. Levanova, and I. L. Glazko. "Features of triamyl citrate synthesis." Fine Chemical Technologies 17, no. 6 (January 24, 2023): 483–91. http://dx.doi.org/10.32362/2410-6593-2022-17-6-483-491.

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Objectives. To find an effective way for obtaining triamyl citrate, an environmentally friendly, biodegradable citric acid ester used as a plasticizer for PVC-based polymer compositions.Methods. The possibilities of heterogeneous catalysis were analyzed using the case study of three commercial samples of macroporous sulfocationites (Amberlyst™ 15, Amberlyst™ 70, and TULSION® 66). Homogeneous catalysis was studied using the example of orthophosphoric acid (H3PO4), while self-catalysis was investigated during esterification of citric acid with amyl alcohol (ROH). The syntheses were carried out under identical conditions: T = 110 °C, the ratio of CA:ROH = 1:5 (mol) amount of catalyst 1 wt % on the reaction mass in a thermostatically controlled reactor of ideal mixing with continuous distillation of the resulting water.Results. It was found that in all variants (even under self-catalysis conditions), the conversion of citric acid in 180 min reached 94–99%. Triamyl citrate was formed after 9 h with a yield of 90% only when using a homogeneous catalyst (H3PO4) and in the presence of a heterogeneous catalyst sample (Amberlyst ™ 15).Conclusions. The revealed differences in the reactivity of the studied sulfocationites (Amberlyst™ 15, Amberlyst ™ 70, and TULSION® 66) confirm the well-known theoretical positions, according to which the kinetic pseudo-homogeneous model of the esterification process of hydroxy acids in excess of aliphatic alcohols is based on the law of acting masses and depends on the specific surface area of the catalyst, which for Amberlyst ™ 15 is of the greatest importance as compared to Amberlyst ™ 70 and TULSION® 66 (m2/g): 53:36:35, respectively.

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Faggiano, Antonio, Maria Ricciardi, and Antonio Proto. "Catalytic Routes to Produce Polyphenolic Esters (PEs) from Biomass Feedstocks." Catalysts 12, no. 4 (April 18, 2022): 447. http://dx.doi.org/10.3390/catal12040447.

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Polyphenolic esters (PEs) are valuable chemical compounds that display a wide spectrum of activities (e.g., anti-oxidative effects). As a result, their production through catalytic routes is an attractive field of research. The present review aims to discuss recent studies from the literature regarding the catalytic production of PEs from biomass feedstocks, namely, naturally occurred polyphenolic compounds. Several synthetic approaches are reported in the literature, mainly bio-catalysis and to a lesser extent acid catalysis. Immobilized lipases (e.g., Novozym 435) are the preferred enzymes thanks to their high reactivity, selectivity and reusability. Acid catalysis is principally investigated for the esterification of polyphenolic acids with fatty alcohols and/or glycerol, using both homogeneous (p-toluensulfonic acid, sulfonic acid and ionic liquids) and heterogeneous (strongly acidic cation exchange resins) catalysts. Based on the reviewed publications, we propose some suggestions to improve the synthesis of PEs with the aim of increasing the greenness of the overall production process. In fact, much more attention should be paid to the use of new and efficient acid catalysts and their reuse for multiple reaction cycles.

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Likhnyovskyi, Ruslan, Yuriy Tsapko, Vitalii Kovalenko, and Natalia Ivashyna. "Regarding the Formation of Wood Material Fire Protection and the Mechanism of its Action." Materials Science Forum 1038 (July 13, 2021): 439–53. http://dx.doi.org/10.4028/www.scientific.net/msf.1038.439.

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The theoretical aspects of wood material fire protection formation by esterification reactions are considered in the article. The reactivity of polysaccharides and polymers from which wood material is composed has been confirmed by the FTIR method. The IR spectra of the original standard samples of lignin and microcrystalline cellulose were taken and after treatment with solutions with concentrations of 10% of the mass. orthophosphoric (Н3РО4) and oxyethylene diphosphonic (CH3C(OH)(H2PO3)2) acids. Electron scanning microscopy revealed the crystallization of inorganic salts on the wood material surface, which play the role of flame retardants, as well as a film of organopolymer (polyhexamethylene guanidine polyphosphate), which forms a foamed layer of coke when heated. Thermogravimetric analysis (TGA) and gas chromatography (GC) methods show the mechanism of action of fire protection provided to wood material. The formation of foamed coke is visually shown and the results on the effectiveness of fire protection on the example of wood material treatment with a mixture of diammonium phosphate and ammonium sulfate are obtained.

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Zdybel, Ewa, Tomasz Zięba, Waldemar Rymowicz, and Ewa Tomaszewska-Ciosk. "Organic Acids of the Microbiological Post-Culture Medium as Substrates to be Used for Starch Modification." Polymers 11, no. 3 (March 12, 2019): 469. http://dx.doi.org/10.3390/polym11030469.

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This study aimed to identify the feasibility of producing highly-substituted starch esters via thermal modification of starch using a post-culture medium of Yarrowia lipolitica yeast. This manuscript describes a successful attempt at potato starch modification with a post-culture medium of Yarrowia lipolitica yeast with different concentrations of organic acids. Starch preparations produced by roasting (130 °C) and these produced by starch reaction with a synthetic acid mixture were compared in terms of the types and number of acid residues esterified with starch. The effectiveness of starch esterification was found to depend on medium composition and to be higher upon the use of a synthetic acid mixture. In addition, a higher reactivity with starch was demonstrated for citric acid than for α-ketoglutaric acid. The highly-substituted starch esters formed as a result of potato starch modification with post-culture medium were characterized by decreased values of thermal parameters of pasting characteristics, determined with a differential scanning calorimeter (DSC), and by compromised resistance to amylolysis. The intensity of these changes increased along with an increasing total percentage of starch ester substitution.

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Briand, Glen G., Andreas Decken, Whitney E. M. M. Shannon, and Eric E. Trevors. "Synthesis, structural characterization, and reactivity of (thiolato)bismuth complexes as potential water-tolerant Lewis acid catalysts." Canadian Journal of Chemistry 96, no. 6 (June 2018): 561–69. http://dx.doi.org/10.1139/cjc-2017-0640.

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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.

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Wang, Hui-Hui, Xue-Qin Zhang, Piao Long, Ai-Ping Zhang, Chuan-Fu Liu, and Run-Cang Sun. "Reaction Behavior of Cellulose in the Homogeneous Esterification of Bagasse Modified with Phthalic Anhydride in Ionic Liquid 1-Allyl-3-methylimidazium Chloride." International Journal of Polymer Science 2016 (2016): 1–9. http://dx.doi.org/10.1155/2016/2361284.

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In order to elucidate the reaction behavior of cellulose component in bagasse, the homogeneous phthalation of bagasse was investigated comparatively with the isolated cellulose in 1-allyl-3-methylimidazium chloride (AmimCl) with phthalic anhydride (PA) at the dosage of 10–50 mmol/g. The phthalation degrees of bagasse and the isolated cellulose were in the range of 5.66% to 22.71% and 11.61% to 44.11%, respectively. A phthalation degree increase of cellulose was proportional to phthalic anhydride dosage due to its regular macromolecular structure and followed the equationyPDI=0.004x-0.02. FT-IR and 2D HSQC NMR analyses confirmed the attachment of phthaloyl group. The phthalation reactivity of the three hydroxyls in the isolated cellulose followed the order of C-6 > C-2 > C-3, and the more selective phthalation to C-6 position was found in the cellulose component in bagasse. These results provide detailed understanding of the homogenous modification mechanism of lignocellulose.

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ASENSIO, G., C. ANDREU, and J. A. MARCO. "ChemInform Abstract: Influence of Structural Factors and Enzyme Type on the Reactivity and Enantioselectivity of the Enzymatic Esterification of Bicyclic meso Dialcohols." ChemInform 24, no. 5 (August 21, 2010): no. http://dx.doi.org/10.1002/chin.199305069.

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Wang, Shuai, and Enrique Iglesia. "Substituent Effects and Molecular Descriptors of Reactivity in Condensation and Esterification Reactions of Oxygenates on Acid–Base Pairs at TiO2 and ZrO2 Surfaces." Journal of Physical Chemistry C 120, no. 38 (September 8, 2016): 21589–616. http://dx.doi.org/10.1021/acs.jpcc.6b07304.

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Journal articles on the topic 'Esterification Reactivity'

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