- Study the Efficiency of Some Esters Based on 2- Ethyl Hexanoic Acid as Synthetic Lubricants
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Esters have many important properties, such as biodegradation, low toxicity, good thermal stability and excellent solvability, because these features are definitely the most versatile of the various types of base fluids currently available and can be modified to provide unique physical and chemical properties that can be designed to meet the lubricant industry's challenges. In this article, Reaction was prepared by various branched synthetic esters of 2- ethyl hexanoic acid with different 2 groups of alcohols, the first one (1-hexanol, 2- ethyl hexanol,1-octanol, 1- dodecanol and 1- hexadecanol), and the second group (neopentyl glycol, trimethylol propane and pentaerythritol). All the preparation compound form were confirmed by examine the physical and chemical properties as (Nuclear Magnetic Resonance, Infra-Red Spectroscopy, Total Acid Number, Density, Thermo Gravimetric Analysis TGA, Specific gravity, Reflective index, Molecular weights estimation and flash point). As a synthetic lubricating oil, the performance of these compounds was studied. Prepared compounds have been found to contain low pour point (PP), high viscosity level (VI) and Newtonian fluid for rheological behavior.
- Kamal, Rasha S.,Nassar, Amal M.,Ahmed, Nehal S.
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p. 7191 - 7200
(2021/11/16)
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- Practical catalytic nitration directly with commercial nitric acid for the preparation of aliphatic nitroesters
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To pursue a sustainable and efficient approach for aliphatic nitroester preparation from alcohol, europium-triflate-catalyzed nitration, which directly uses commercial nitric acid, has been successfully developed. Gram scalability with operational ease showed its practicability.
- An, Jichao,He, Pan,Li, Wenhao,Liu, Peipei,Si, Mengyuan,Yang, Bo,Yang, Guanyu
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p. 6612 - 6616
(2020/09/21)
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- Process for the production of esters
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A process for making methyl esters in high yields. The process comprises contacting aliphatic or aromatic aldehydes and methanol with a homogeneous dimeric ruthenium catalyst, to catalyze the dehydrogenative coupling between aliphatic or aromatic aldehydes and methanol. The reaction is highly selective (99.9%) toward the formation of methyl esters over homoesters and alcohols and operates at temperatures of less than 100° C. for 2-8 hours.
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Page/Page column 2; 3
(2020/03/18)
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- Iron-catalyzed selective production of methyl esters from aldehydes
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A process for making methyl esters in high yields is provided. The process comprises contacting aliphatic or aromatic aldehydes and methanol with an iron catalyst, to catalyze the dehydrogenative coupling between aliphatic or aromatic aldehydes and methanol. The reaction is highly selective (99.9%) toward the formation of methyl esters over homoesters and alcohols and operates at temperatures of less than 100° C. for 2-8 hours.
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Page/Page column 2-3
(2020/04/01)
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- Manganese Pincer Complexes for the Base-Free, Acceptorless Dehydrogenative Coupling of Alcohols to Esters: Development, Scope, and Understanding
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Aliphatic PNP pincer-supported earth-abundant manganese(I) dicarbonyl complexes behave as effective catalysts for the acceptorless dehydrogenative coupling of a wide range of alcohols to esters under base-free conditions. The reaction proceeds under neat conditions, with modest catalyst loading and releasing only H2 as byproduct. Mechanistic aspects were addressed by synthesizing key species related to the catalytic cycle (characterized by X-ray structure determination, multinuclear (1H, 13C, 31P, 15N, 55Mn) NMR, infrared spectroscopy, inter alia), by studying elementary steps connected to the postulated mechanism, and by resorting to DFT calculations. As in the case of related ruthenium and iron PNP catalysts, the dehydrogenation results from cycling between the amido and amino-hydride forms of the PNP-Mn(CO)2 scaffold. For the dehydrogenation of alcohols into aldehydes, our results suggest that the highest energy barrier corresponds to the hydrogen release from the amino-hydride form, although its value is close to that of the outer-sphere dehydrogenation of the alcohol into aldehyde. This contrasts with the ruthenium and iron catalytic systems, where dehydrogenation of the substrate into aldehyde is less energy-demanding compared to hydrogen release from the cooperative metal-ligand framework.
- Nguyen, Duc Hanh,Trivelli, Xavier,Capet, Frédéric,Paul, Jean-Fran?ois,Dumeignil, Franck,Gauvin, Régis M.
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p. 2022 - 2032
(2017/08/14)
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- Acceptorless dehydrogenative coupling of alcohols catalysed by ruthenium PNP complexes: Influence of catalyst structure and of hydrogen mass transfer
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Base-free catalytic acceptorless dehydrogenative homo-coupling of alcohols to esters under neat conditions was investigated using a combined organometallic synthesis and kinetic modelling approach. The considered bifunctional ruthenium aliphatic PNP complexes are very active, affording TONs up to 15,000. Notably, gas mass transfer issues were identified, which allowed us to rationalize previous observations. Indeed, the reaction kinetics are limited by the rate of transfer from the liquid phase to the gas phase of the hydrogen co-produced in the reaction. Mechanistically speaking, this relates to the interconverting couple amido monohydride/amino bishydride. Overcoming this by switching into the chemical regime leads to an initial turnover frequency increase from about 2000 up to 6100?h?1. This has a significant impact when considering assessment of novel or reported catalytic systems in this type of reaction, as overlooking of these engineering aspects can be misleading.
- Zhang, Lei,Raffa, Guillaume,Nguyen, Duc Hanh,Swesi, Youssef,Corbel-Demailly, Louis,Capet, Frédéric,Trivelli, Xavier,Desset, Simon,Paul, Sébastien,Paul, Jean-Fran?ois,Fongarland, Pascal,Dumeignil, Franck,Gauvin, Régis M.
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p. 331 - 343
(2016/07/06)
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- Efficient and simple approaches towards direct oxidative esterification of alcohols
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The present article describes novel oxidative protocols for direct esterification of alcohols. The protocols involve successful demonstrations of both "cross" and "self" esterification of a wide variety of alcohols. The cross-esterification proceeds under a simple transition-metal-free condition, containing catalytic amounts of TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy)/TBAB (tetra-n-butylammonium bromide) in combination with oxone (potassium peroxo monosulfate) as the oxidant, whereas the self-esterification is achieved through simple induction of Fe(OAc)2/dipic (dipic=2,6-pyridinedicarboxylic acid) as the active catalyst under an identical oxidizing environment. One-pot oxidative esterification: A wide variety of alcohols undergo transition-metal-free (in the presence of oxone/2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)/tetra-n-butylammonium bromide (TBAB)) selective "cross" esterification in moderate to excellent yields (see Figure). The "self" esterification process has however been achieved in the presence of Fe(OAc)2/2,6-pyridinedicarboxylic acid (dipic) as the active catalytic species under a similar oxidizing environment.
- Ray, Ritwika,Jana, Rahul Dev,Bhadra, Mayukh,Maiti, Debabrata,Lahiri, Goutam Kumar
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supporting information
p. 15618 - 15624
(2016/02/18)
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- Efficient dimeric esterification of alcohols with NBS in water using l-proline as catalyst
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The L-proline-catalyzed oxidation of aliphatic primary alcohols with N-bromosuccimide (NBS) in water at room temperature to afford the corresponding dimeric esters in good to excellent yields was described. This pathway of dimeric esterification was proved to be very simple and environmentally friendly.
- Liu, Xiuhong,Wu, Jun,Shang, Zhicai
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experimental part
p. 75 - 83
(2011/11/05)
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- Dehydrogenative coupling of primary alcohols to form esters catalyzed by a ruthenium N-heterocyclic carbene complex
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The ruthenium complex [RuCl2(IiPr)(p-cymene)] catalyzes the direct condensation of primary alcohols into esters and lactones with the release of hydrogen gas. The reaction is most effective with linear aliphatic alcohols and 1,4-diols and is believed to proceed with a ruthenium dihydride as the catalytically active species.
- Solvhoj, Amanda,Madsen, Robert
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experimental part
p. 6044 - 6048
(2012/01/13)
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- Selective oxidation of primary alkanols into the "symmetrical" esters with the H2O2-MBr-HCl system
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Oxidation of linear or branched primary alkanols with H2O 2-MBr (M = Li, Na, K)-HCl system in water affords the corresponding "symmetrical" esters in almost quantitative yield.
- Nikishin,Sokova,Kapustina
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experimental part
p. 310 - 312
(2011/11/05)
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- Nickel-catalyzed Tishchenko reaction via hetero-nickelacycles by oxidative cyclization of aldehydes with nickel(0) complex
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A Ni(0)-catalyzed Tishchenko reaction which can be applied to a variety of aliphatic aldehydes (1°, 2°, 3°) and aromatic aldehydes was developed. The reaction might proceed via a hetero-nickelacycle intermediate.
- Ogoshi, Sensuke,Hoshimoto, Yoichi,Ohashi, Masato
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supporting information; experimental part
p. 3354 - 3356
(2010/07/14)
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- Oxidation of alkanols into "symmetric" esters with the system Ce(SO4)2-LiBr
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A method for the synthesis of "symmetric" esters based on the oxidation of primary straight-and iso-chain aliphatic alcohols C6 -C11 with the system Ce(SO4)2-LiBr in water has been suggested.
- Nikishin,Sokova,Kapustina
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experimental part
p. 303 - 308
(2010/07/09)
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- Oxone/sodium chloride: A simple and efficient catalytic system for the oxidation of alcohols to symmetric esters and ketones
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An efficient method for the oxidation of alcohols is presented. The use of catalytic amounts of sodium chloride in combination with oxone allows the conversion primary aliphatic alcohols to symmetric esters. Secondary alcohols can be easily oxidized to ketones, and benzylic alcohols are converted to the corresponding aldehydes. The method is cost effective and enviromentally benign. Copyright Taylor & Francis Group, LLC.
- Schulze, Agnes,Pagona, Georgia,Giannis, Athanassios
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p. 1147 - 1156
(2007/10/03)
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- Oxidative dimerization of primary alcohols to esters catalyzed by iridium complexes
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Primary alcohols undergo efficiently oxidative dimerization by iridium complexes under air without any solvent to form esters in fair to good yields. For instance, the reaction of 1-dodecanol in the presence of [IrCl(coe)2]2 (3 mol %) at 95 °C for 15 h produced dodecyl dodecanoate in 91% isolated yield. This is the first successful Ir-catalyzed oxidative dimerization of primary alcohols to esters using air as an oxidant. Various primary alcohols are converted to the corresponding esters in fair to good yields.
- Izumi, Aki,Obora, Yasushi,Sakaguchi, Satoshi,Ishii, Yasutaka
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p. 9199 - 9201
(2007/10/03)
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- Pharmaceutical compositions for transdermal administration of anti-inflammatory agents
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The invention concerns a pharmaceutical composition for transdermal administration comprising: a polymeric release matrix capable of forming a soft film after drying, selected among cellulose polymers or copolymers, said matrix being present at a concentration not exceeding 6% of the composition weight; an active principle selected among the group of non-steroid anti-inflammatory agents comprising at least a metal carboxylic or carboxitate group; a transcutaneous absorption promoter of the active principle; water; and at least a physiologically acceptable non-aqueous solvent capable of dissolving the release matrix, the active principle and transcutaneous absorption promoter and to be rapidly eliminated by evaporation in contact with the skin.
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- A Kinetic Study of 2-Ethyl-1-hexanol Oxidation by Dichromate Using Clay-Supported 1-Butyl 4-aza-1-azonia Bicyclo[2.2.2]octane Chloride as the Phase-Transfer Catalyst
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Selective oxidation of primary alcohols to aldehydes is a long-standing problem of organic chemistry (Bueler, C. A.; Pearson, D. E. Survey of Organic Synthesis; Wiley-Interscience: New York, 1977; Vol. 2, p 480; House, H. O. Modern Synthetic Reactions, 2nd. ed.; W. A. Benjamin: Menlo Park, California, 1972; p 257; Epstein, W. W.; Sweet, F. W. Chem. Rev. 1967, 67, 247; Landini, D. ; Montanari, F.; Rolla, F. Synthesis 1979, 134). The use of potassium dichromate as a synthetically useful oxidizing agent is reported for the oxidation of an industrially important lipophilic alcohol, employing modified clay as the phase-transfer catalyst. The phase-transfer catalysis results in nearly complete oxidation of the 2-ethylhexanol in 40 min at room temperature, with high selectivity to the 2-ethylhexanal, compared to 48 h in its absence. Kinetic studies show the reaction occurs via transfer of Cr2O 72- into the organic phase. The emphasis will be on simplicity of the condition as a preparative organic method, selectivity with regard to over-oxidation, efficiency, and mildness of conditions.
- Ghiaci,Kalbasi,Sedaghat
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p. 936 - 938
(2013/09/05)
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- Symmetric esters by Tischtschenko reaction of aldehydes catalyzed by bi- and tridentate catalysts derived from catechol or gallol, trimethylaluminum and isopropanol
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New inexpensive aluminum-based bidentate and tridentate chelates were found to be efficient catalysts for the Tischtschenko reaction of aldehydes. The conversion of n-butanal to n-butyl n-butyrate using catechol-derived catalysts at room temperature was complete (the yield of the butyrate was 99%) in two hours. High yields of symmetric esters were obtained in the case of n-alkyl and α-branched aliphatic aldehydes whereas reactivity of unsaturated aldehydes was found to be poor. Selected reactive intermediates were studied computationally at the (pBP)/DNPP level using the Spartan program. The results of computational studies indicate that in the case of the catechol-derived catalyst bidentate chelation of two aluminum atoms to an oxygen atom of aldehyde to form a structure '(O-Al)2O=CAld.' is less favorable than monodentate chelation to one aluminum atom activated by the other aluminum to form a structure 'O-Al-O-Al-O=CAld.'. The structure of this activated monodentate system clearly resembles more closely the transition state of the hydride-transfer step of the Tischtschenko reaction than the corresponding non-activated monodentate system 'O-Al'+'O-Al-O=CAld.'.
- Simpura, Ilkka,Nevalainen, Vesa
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p. 9867 - 9872
(2007/10/03)
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- Oxidation of primary alcohols to acyl fluorides using BrF3
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Aliphatic and alicyclic primary alcohols when treated with BrF3 were rapidly oxidized to the corresponding acyl fluorides. The reaction is of an ionic nature. The main by-product was found to be the symmetrical ester which originates from the reaction between the acyl fluoride and unreacted starting alcohol.
- Rozen, Shlomo,Ben-David, Iris
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p. 145 - 147
(2007/10/03)
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- Process for esters
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Esters are prepared directly from 2-substituted alcohols, such as Guerbet alcohols, by dehydrogenating and esterifying the alcohol at 170°C-240°C in the presence of a catalyst system comprising (i) platinum on activated carbon, zinc oxide or zinc C2-C20 carboxylate and (ii) NaOH, KOH or LiOH. Mixed esters may also be prepared from appropriate mixtures of 2-substituted alcohols.
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- CHEMISTRY OF TRIVALENT IODINE-III THE ACTION OF IODOBENZENE DICHLORIDE ON PRIMARY ALCOHOLS AND ALDEHYDES
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Iodobenzene dichloride reacts with saturated primary alcohols at room temperature in the presence of pyridine to give esters and acid chlorides.With the corresponding aldehydes, only the latter type of product is obtained.While pivaldehyde raects normally, benzaldehyde is unaffected by the reagent under the same conditions.Presence of moisture results in formation of acids.It is suggested that reactions of both types of substrates involve base catalysed fragmentation of iodonium intermediates.
- Mohandas, T. P.,Mamman, Ajit, S.,Nair, P. Madhavan
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p. 1187 - 1188
(2007/10/02)
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