4542-57-8Relevant academic research and scientific papers
Mechanism and kinetics of 1-dodecanol etherification over tungstated zirconia
Rorrer, Julie,He, Ying,Toste, F. Dean,Bell, Alexis T.
, p. 13 - 23 (2017)
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.
Silver(I)-Catalyzed Reductive Cross-Coupling of Aldehydes to Structurally Diverse Cyclic and Acyclic Ethers
Dong, Guichao,Li, Chuang,Liang, Ting,Xu, Xin,Xu, Zhou
supporting information, p. 1817 - 1821 (2022/03/16)
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.
Effect of Alcohol Structure on the Kinetics of Etherification and Dehydration over Tungstated Zirconia
Rorrer, Julie,Pindi, Suresh,Toste, F. Dean,Bell, Alexis T.
, p. 3104 - 3111 (2018/09/06)
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.
An ether compound of green high-efficient synthetic method (by machine translation)
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Paragraph 0058, (2018/07/07)
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)
Continuous-Flow Multistep Synthesis of Cinnarizine, Cyclizine, and a Buclizine Derivative from Bulk Alcohols
Borukhova, Svetlana,Nol, Timothy,Hessel, Volker
, p. 67 - 74 (2016/01/16)
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.
PROCESS FOR MAKING LINEAR LONG-CHAIN ALKANES FROM RENEWABLE FEEDSTOCKS USING CATALYSTS COMPRISING HETEROPOLYACIDS
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Page/Page column 34; 35, (2014/10/15)
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.
Acid-catalyzed etherification of glycerol with long-alkyl-chain alcohols
Gaudin, Pierrick,Jacquot, Roland,Marion, Philippe,Pouilloux, Yannick,Jér?me, Fran?ois
experimental part, p. 719 - 722 (2012/05/20)
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
Synthesis of 2,3-dihydroquinolin-4(1H)-ones through catalytic metathesis of o-alkynylanilines and aldehydes
Saito, Akio,Kasai, Jun,Odaira, Yu,Fukaya, Haruhiko,Hanzawa, Yuji
supporting information; scheme or table, p. 5644 - 5647 (2009/12/08)
(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
Gold-catalyzed substitution reaction with ortho-alkynylbenzoic acid alkyl ester as an efficient alkylating agent
Aikawa, Haruo,Tago, Sakie,Umetsu, Kazuteru,Haginiwa, Naomichi,Asao, Naoki
experimental part, p. 1774 - 1784 (2009/06/20)
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.
[IrCl2Cp*(NHC)] complexes as highly versatile efficient catalysts for the cross-coupling of alcohols and amines
Prades, Amparo,Corberan, Rosa,Poyatos, Macarena,Peris, Eduardo
scheme or table, p. 11474 - 11479 (2009/12/03)
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.
