- Mechanism and kinetics of 1-dodecanol etherification over tungstated zirconia
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Growing interest in finding renewable alternatives to conventional fossil fuels and petroleum-derived specialty chemicals has motivated the investigation of biomass-derived alcohols to make ethers as diesel additives or lubricants. To optimize the direct etherification of long chain alcohols in the liquid phase, it is necessary to develop an understanding of the kinetics and mechanism of etherification and dehydration reactions. In this study, tungstated zirconia was identified as a selective solid-acid catalyst for the liquid-phase etherification of 1-dodecanol. Investigations of the mechanism and kinetics of this reaction suggest that cooperation between Br?nsted- and Lewis-acid sites on tungstated zirconia enhances the selectivity to ether by increasing the surface concentration of adsorbed alcohol, thereby promoting bi-molecular ether formation relative to unimolecular alcohol dehydration. The suggested rate limiting step for etherification is the formation of a C–O bond between two adsorbed alcohol molecules, and the suggested rate-limiting step for dehydration is the cleavage of the C–H bond of the β-carbon atom in an adsorbed alcohol. Measurements of the kinetic isotope effects for etherification and dehydration support the proposed mechanism. A microkinetic model based on the proposed mechanism for dodecanol etherification and dehydration over tungstated zirconia accurately describes the observed effects of alcohol concentration and product inhibition.
- Rorrer, Julie,He, Ying,Toste, F. Dean,Bell, Alexis T.
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- Silver(I)-Catalyzed Reductive Cross-Coupling of Aldehydes to Structurally Diverse Cyclic and Acyclic Ethers
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A range of medium-sized cyclic ethers (5 to 11 membered) have been effectively synthesized through intramolecular reductive coupling of dialdehydes initiated by 50 ppm to 0.5% of AgNTf2 with hydrosilane at 25 °C. The catalytic system is also suitable for the coupling of two different monoaldehydes to provide unsymmetrical ethers. This protocol features broad functional group compatibility, high product diversity, high efficiency, and utility in the late-stage modification of complex biorelevant molecules.
- Dong, Guichao,Li, Chuang,Liang, Ting,Xu, Xin,Xu, Zhou
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supporting information
p. 1817 - 1821
(2022/03/16)
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- Effect of Alcohol Structure on the Kinetics of Etherification and Dehydration over Tungstated Zirconia
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Linear and branched ether molecules have attracted recent interest as diesel additives and lubricants that can be produced from biomass-derived alcohols. In this study, tungstated zirconia was identified as a selective and green solid acid catalyst for the direct etherification of primary alcohols in the liquid phase, achieving ether selectivities of >94 % for C6–C12 linear alcohol coupling at 393 K. The length of linear primary alcohols (C6–C12) was shown to have a negligible effect on apparent activation energies for etherification and dehydration, demonstrating the possibility to produce both symmetrical and asymmetrical linear ethers. Reactions over a series of C6 alcohols with varying methyl branch positions indicated that substituted alcohols (2°, 3°) and alcohols with branches on the β-carbon readily undergo dehydration, but alcohols with branches at least three carbons away from the -OH group are highly selective to ether. A novel model compound, 4-hexyl-1dodecanol, was synthesized and tested to further demonstrate this structure–activity relationship. Trends in the effects of alcohol structure on selectivity were consistent with previously proposed mechanisms for etherification and dehydration, and help to define possible pathways to selectively form ethers from biomass-derived alcohols.
- Rorrer, Julie,Pindi, Suresh,Toste, F. Dean,Bell, Alexis T.
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p. 3104 - 3111
(2018/09/06)
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- An ether compound of green high-efficient synthetic method (by machine translation)
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The invention discloses an ether compound of green high-efficient synthetic method, energy-saving environmental protection, comprising: mild reaction system, uses aldehyde, silane as the starting material, under the action of the silver salt in a price, for in solvent-free conditions, through reducing the - coupling - cheng mi reaction, realization of high efficiency alcohol of preparation. Synthesis method of the invention has the advantages of low dosage of catalyst, solvent-free, conversion and high yield, the reaction time is short, safe and stable, easy to operate, the product only distillation purification without any additional organic solvent, the whole range of green, environmental protection, high efficiency and the like, can overcome the defects of the prior art, it has very good industrial application value. (by machine translation)
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Paragraph 0058
(2018/07/07)
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- Continuous-Flow Multistep Synthesis of Cinnarizine, Cyclizine, and a Buclizine Derivative from Bulk Alcohols
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Cinnarizine, cyclizine, buclizine, and meclizine belong to a family of antihistamines that resemble each other in terms of a 1-diphenylmethylpiperazine moiety. We present the development of a four-step continuous process to generate the final antihistamines from bulk alcohols as the starting compounds. HCl is used to synthesize the intermediate chlorides in a short reaction time and excellent yields. This methodology offers an excellent way to synthesize intermediates to be used in drug synthesis. Inline separation allows the collection of pure products and their immediate consumption in the following steps. Overall isolated yields for cinnarizine, cyclizine, and a buclizine derivative are 82, 94, and 87 %, respectively. The total residence time for the four steps is 90 min with a productivity of 2 mmol h-1. The incredible bulk: Bulk alcohols are converted continuously into chlorides using HCl in a microflow. A reaction network that consists of four steps and two inline separations leads to the continuous preparation of cinnarizine, cyclizine, and a buclizine derivative with yields of 82, 94, and 87 %, respectively. The total residence time for the four steps is 90 min with a productivity of 2 mmol h-1.
- Borukhova, Svetlana,Nol, Timothy,Hessel, Volker
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- PROCESS FOR MAKING LINEAR LONG-CHAIN ALKANES FROM RENEWABLE FEEDSTOCKS USING CATALYSTS COMPRISING HETEROPOLYACIDS
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A hydrodeoxygenation process for producing a linear alkane from a feedstock comprising a saturated or unsaturated C10-18 oxygenate that comprises an ester group, carboxylic acid group, carbonyl group and/or alcohoi group is disclosed. The process comprises contacting the feedstock with a catalyst composition comprising a metal catalyst and a heteropolyacid or heteropo.yacid salt, at a temperature between about 240 °C to 280 °C and a hydrogen gas pressure of at least 300 psi. The metal catalyst comprises copper in certain embodiments. By contacting the feedstock with the catalyst composition under these temperature and pressure conditions, the C10-18 oxygenate is hydrodeoxygenated to a linear alkane that has the same carbon chain length as the C10-18 oxygenate.
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Page/Page column 34; 35
(2014/10/15)
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- Acid-catalyzed etherification of glycerol with long-alkyl-chain alcohols
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Rubbing the right way: The direct etherification of glycerol with long-chain alcohols typically suffers from poor contact between the reaction phases. A dodecylbenzene sulfonic acid catalyst enables a better contact between the glycerol and alcohol phases, enhancing the yield of monoalkyl glyceryl ethers and offering a direct route for the synthesis of these surfactants. Copyright
- Gaudin, Pierrick,Jacquot, Roland,Marion, Philippe,Pouilloux, Yannick,Jér?me, Fran?ois
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experimental part
p. 719 - 722
(2012/05/20)
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- Synthesis of 2,3-dihydroquinolin-4(1H)-ones through catalytic metathesis of o-alkynylanilines and aldehydes
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(Chemical Equation Presented) SbF5-MeOH catalytic system efficiently promotes the alkyne-carbonyl metathesis of o-alkynylaniline derivatives and aldehydes to afford 2,3-disubstituted dihydroquinolinones in moderate to high yields with high tran
- Saito, Akio,Kasai, Jun,Odaira, Yu,Fukaya, Haruhiko,Hanzawa, Yuji
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supporting information; scheme or table
p. 5644 - 5647
(2009/12/08)
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- Gold-catalyzed substitution reaction with ortho-alkynylbenzoic acid alkyl ester as an efficient alkylating agent
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ortho-Alkynylbenzoic acid alkyl esters behave as alkylating agents in combination with gold catalysts. The reaction with alcohols occurs smoothly in the presence of catalytic amounts of Ph3PAuCl and AgOTf under mild conditions to produce the corresponding ether products in high yields. The protocol is also useful for Friedel-Crafts alkylation and N-alkylation of sulfonamides. The reaction likely proceeds through the gold-induced in situ construction of leaving groups and subsequent nucleophilic attack of nucleophiles, such as alcohols, aromatic compounds, and sulfonamides.
- Aikawa, Haruo,Tago, Sakie,Umetsu, Kazuteru,Haginiwa, Naomichi,Asao, Naoki
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experimental part
p. 1774 - 1784
(2009/06/20)
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- [IrCl2Cp*(NHC)] complexes as highly versatile efficient catalysts for the cross-coupling of alcohols and amines
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A comparative study on the catalytic activity of a series of [IrCl 2Cp*(NHC)] complexes in several C-O and C-N coupling processes implying hydrogen-borrowing mechanisms has been performed. The compound [IrCl2Cp*(InBu)] (Cp* = pentamethyl cyclopentadiene; InBu = 1,3-di-n-butylimidazolylidene) showed to be highly effective in the cross-coupling reactions of amines and alcohols, providing high yields in the production of unsymmetrical ethers and N-alkylated amines. A remarkable feature is that the processes were carried out in the absence of base, phosphine, or any other external additive. A comparative study with other known catalysts, such as Shvo's catalyst, is also reported.
- Prades, Amparo,Corberan, Rosa,Poyatos, Macarena,Peris, Eduardo
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scheme or table
p. 11474 - 11479
(2009/12/03)
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- Gold-catalyzed etherification and friedel - Crafts alkylation using ortho-alkynylbenzoic acid alkyl ester as an efficient alkylating agent
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A gold-catalyzed alkylation of alcohols and aromatic compounds is described. The reaction of ortho-alkynylbenzoic acid alkyl esters with alcohols or aromatic compounds occurs in the presence of catalytic amounts of Ph 3PAuCl and AgOTf under mild conditions to produce corresponding ethers or Friedel-Crafts alkylation products in good to high yields. The reaction likely proceeds through the gold-induced in situ construction of leaving groups and subsequent nucleophilic attack of alcohols or aromatic compounds.
- Asao, Naoki,Aikawa, Haruo,Tago, Sakie,Umetsu, Kazuteru
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p. 4299 - 4302
(2008/02/12)
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- METHOD FOR DEHYDRATING FATTY ALCOHOLS
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The invention relates to a method for producing hydrocarbons by dehydrating primary alcohols during which trifluoromethane sulfonic acid is used as a dehydration catalyst.
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Page/Page column 4
(2008/06/13)
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- Process to convert linear alkanes into alpha olefins
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This invention provides for a process to convert branched or linear alkanes to branched or linear alpha olefins (AO) of the same carbon number. The process comprises the steps of: a) halogenating linear alkanes, branched alkanes, or a mixture of linear and branched alkane to produce a mixture containing primary mono-haloalkanes and hydrogen halide; b) separating the hydrogen halide from the mixture and optionally neutralizing it with a metal oxide to produce a partially halogenated metal oxide and/or metal halide which may be regenerated; c) separating the primary mono-haloalkanes from the mixture; d) reacting the separated primary mono-haloalkanes with a metal oxide to produce a mixture of products that contains alpha olefins, unconverted primary mono-haloalkanes, possibly other reaction products, and a partially halogenated metal oxide and/or metal halide which may be regenerated; e) regenerating the partially halogenated metal oxide and/or metal halide to halogen and/or acid and a metal oxide (such as Cl2) for recycle by reaction with air or oxygen ; and f) removing the unreacted primary mono-haloalkane from the reaction mixture and then purifying the alpha olefin.
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Page/Page column 7
(2008/06/13)
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- Process to convert alkanes into primary alcohols
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This invention provides a process to convert alkanes to primary alcohols of the same carbon number. Carbon numbers of particular interest are C8 to C18. The process comprises the steps of: a) halogenating a linear or branched (or mixture of linear and branched) alkane to produce a mixture of primary mono-haloalkanes, internal mono-haloalkanes, unreacted alkanes, hydrogen halide, and possibly multi-haloalkanes in the presence of a catalyst and/or by heating the reaction mixture; b) separating the hydrogen halide from the mixture and optionally neutralizing it with a metal oxide to produce a partially halogenated metal oxide and/or metal halide which may be regenerated; c) separating the primary mono-haloalkanes from the mixture; d) reacting the separated primary mono-haloalkanes in a reactor with a metal oxide or combination of metal oxides and water to convert the aforesaid primary mono-haloalkane to a mixture of products that contains primary alcohols, unconverted primary mono-haloalkanes, and possibly other reaction products, and a partially halogenated metal oxide and/or metal halide which may be regenerated; e) regenerating the partially halogenated metal oxide and/or metal halide to halogen (such as Cl2) and/or acid and a metal oxide for recycle by reaction with air or oxygen; and f) removing the unreacted primary mono-haloalkane from the reaction mixture and then purifying the primary alcohol.
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Page/Page column 7
(2008/06/13)
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- Synthesis of amphiphilic thiatrimethinecyanines
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Preparation conditions were optimized for 2-methyl-5-chlorobenzothiazolium quaternary salts with long-chain N-alkyl substituents (C12H 25, C15H31, C18H37). They were used in the synthesis of thiatrimethinecyanines conteining in the meso-position phenyl, p-chlorophenyl, or p-fluorophenyl groups.
- Orlova,Kolchina,Shakirov,Gerasimova,Shelkovnikov
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p. 228 - 231
(2007/10/03)
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- Process for producing ether compound
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Ether compounds, which are useful as solvents, cosmetics, detergents, lubricants, emulsifiers and so on, are produced by reacting (a) a hydroxy compound with a carbonyl compound of (b) a carbonyl compound under hydrogen atmosphere in the presence of a catalyst with ease and at a low cost. The reaction is carried out while removing out produced water by using a dehydrating agent during the reaction; by distilling off the water by azeotropic dehydration and the like; or by blowing gases such as hydrogen gas to flow through the reaction system.
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- Fatty methyl ester hydrogenation to fatty alcohol Part II: Process issues
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Fatty alcohols are produced by hydrogenating fatty methyl esters in slurry phase in the presence of copper chromite catalyst at temperatures of 250-300 °C and hydrogen pressures of 2000-3000 psi. The fatty methyl ester, catalyst, and hydrogen are fed to the reactor cocurrently. The product slurry is passed through gas-liquid separators and then through a continuous filtration system for removal of the catalyst. A portion of the used catalyst in crude alcohol is recycled to the hydrogenator. The overall efficiency of the process depends upon the intrinsic activity, life, and filterability of the catalyst. The fatty alcohol producer therefore requires a catalyst with high activity, long life, and good separation properties. The main goal of the present laboratory investigation was to develop a superior copper chromite catalyst for the slurry-phase process. Two copper chromite catalysts, prepared by different procedures, were tested for methyl ester hydrogenolysis activity, reusability, and filtration characteristics. The reaction was carried out in a batch autoclave at 280 °C and 2000-3000 psi hydrogen pressure. The reaction rates were calculated by assuming a kinetic mechanism that was first-order in methyl ester concentration. The catalyst with the narrower particle size distribution was 30% more active, filtered faster, and maintained activity for several more uses than the catalyst with the broader particle size distribution. X-ray photoelectron spectroscopy data showed higher surface copper concentrations for the former catalyst.
- Rieke,Thakur,Roberts,White
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p. 341 - 345
(2007/10/03)
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- Influences on the Selectivity of the Kolbe versus the Non-Kolbe Electrolysis in the Anodic Decarboxylation of Carboxylic Acids
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The anodic decarboxylation of 3-oxanonanoic acid (2a) and 3-oxapentadecanoic acid (2b) in methanol leads exclusively to products of the non-Kolbe electrolysis.The influence of coelectrolysis, solvent, current density, degree of neutralization and chain length of the alkoxy group on the anodic decarboxylation of 2a, b have been investigated.An extended alkyl chain in the alkoxy group, coelectrolysis with long-chain fatty acids, ethanol or dimethylformamide as solvent, and a high current density favor the Kolbe coupling against the non-Kolbe electrolysis.Key Words: Kolbe electrolysis/ Non-Kolbe electrolysis/ Carboxylic acids, α-alkoxy-/ Solvent effects
- Klocke, Elisabeth,Matzeit, Agnes,Gockeln, Marianne,Schaefer, Hans J.
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p. 1623 - 1630
(2007/10/02)
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- ALKYLATION OF PHTHALIMIDE WITH HIGHER ALKYL BROMIDES UNDER CONDITIONS OF PHASE-TRANSFER CATALYSIS.
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N-alkylphthalimides, used as intermediates for synthesis of primary amines, are obtained in good yields by heating potassium phthalimide with alkyl halides in dimethylforamide (DMFA) and other polar solvents. Phthalimide is alkylated by higher alkyl bromides, RBr, where R equals C//4H//9, C//1//2H//2//5, C//1//6H//3//3, in toluene (at 95 degree ) in high yields in presence of solid K//2CO//3 and a phase-transfer catalyst, methyl methyltrioctylammonium sulfate. The reaction of phthalimide with dodecyl bromide under the usual conditions of phasetransfer catalysis (organic phase-50% NaOH) is accompanied by hydrolysis of phthalimide and formation of a complex mixture of products, from which N-dodecylphthalimide, dodecylamine, 1-dodecanol, dodecyl ether, and 1-dodecene were isolated.
- Vasilevskaya,Grineva,Chernousova,Grankina,Andrievskii
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p. 220 - 222
(2007/10/02)
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- SOLID - LIQUID PHASE TRNSFER CATALYSIS USING SOLID SODIUM HYDROXIDE IN PREPARATIVE ETHERS SYNTHESIS
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Preparative ethers synthesis can be performed using P.T.C. if solid sodium hydroxide is used as basic medium.In this case, side reactions ( eg: hydrolysis or elimination ) are avoided.Moreover, secondary disymmetrical ethers can be synthesized starting from an alcohol and a secondary alkyl halide in acceptable yields.
- Dou, H. JM.,Delfort, B.,Hassanaly, P.,Gallo, R.,Kister, J.
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p. 421 - 426
(2007/10/02)
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