629-64-1Relevant academic research and scientific papers
Thiourea-Mediated Halogenation of Alcohols
Mohite, Amar R.,Phatake, Ravindra S.,Dubey, Pooja,Agbaria, Mohamed,Shames, Alexander I.,Lemcoff, N. Gabriel,Reany, Ofer
supporting information, p. 12901 - 12911 (2020/11/26)
The halogenation of alcohols under mild conditions expedited by the presence of substoichiometric amounts of thiourea additives is presented. The amount of thiourea added dictates the pathway of the reaction, which may diverge from the desired halogenation reaction toward oxidation of the alcohol, in the absence of thiourea, or toward starting material recovery when excess thiourea is used. Both bromination and chlorination were highly efficient for primary, secondary, tertiary, and benzyl alcohols and tolerate a broad range of functional groups. Detailed electron paramagnetic resonance (EPR) studies, isotopic labeling, and other control experiments suggest a radical-based mechanism. The fact that the reaction is carried out at ambient conditions, uses ubiquitous and inexpensive reagents, boasts a wide scope, and can be made highly atom economic, makes this new methodology a very appealing option for this archetypical organic reaction.
Silver/NBS-Catalyzed Synthesis of α-Alkylated Aryl Ketones from Internal Alkynes and Benzyl Alcohols via Ether Intermediates
Chun, Supill,Chung, Young Keun
supporting information, p. 5583 - 5586 (2018/09/21)
The silver hexafluoroantimonate/N-bromosuccinimide (NBS)-catalyzed synthesis of α-alkylated aryl ketones with a tertiary carbon center from internal alkynes and benzyl alcohols is reported. This reaction proceeds via the etherification of benzyl alcohols with an in situ generated benzyl bromide, formed by the reaction of benzyl alcohol with a catalytic amount of NBS and AgSbF6. Ag-catalyzed C-O cleavage of the ether leads to a tolyl radical, which undergoes addition to the alkyne, ultimately leading to the α-alkylated aryl ketone products.
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.
Synthesis of Benzyl Alkyl Ethers by Intermolecular Dehydration of Benzyl Alcohol with Aliphatic Alcohols under the Effect of Copper Containing Catalysts
Bayguzina,Gimaletdinova,Khusnutdinov
, p. 1148 - 1155 (2018/10/24)
Synthesis of benzyl alkyl ethers was performed in high yields by intermolecular dehydration of benzyl and primary, secondary, tertiary alcohols under the effect of copper containing catalysts. The formation of benzyl alkyl ethers occurs with participation of benzyl cation.
Organohalide-catalyzed dehydrative O-alkylation between alcohols: A facile etherification method for aliphatic ether synthesis
Xu, Qing,Xie, Huamei,Chen, Pingliang,Yu, Lei,Chen, Jianhui,Hu, Xingen
supporting information, p. 2774 - 2779 (2015/05/27)
Organohalides are found to be effective catalysts for dehydrative O-alkylation reactions between alcohols, providing selective, practical, green, and easily scalable homo- and cross-etherification methods for the preparation of useful symmetrical and unsymmetrical aliphatic ethers from the readily available alcohols. Mechanistic studies revealed that organohalides are regenerated as reactive intermediates and recycled to catalyze the reactions.
Intermolecular dehydration of alcohols by the action of copper compounds activated with carbon tetrabromide. synthesis of ethers
Khusnutdinov, R. I.,Bayguzina, A. R.,Gimaletdinova, L. I.,Dzhemilev, U. M.
, p. 1191 - 1196,6 (2020/10/15)
Copper compounds of the general formula CuXn (X = Cl, Br, I, acac, OAc, C7H4O3, C7H 5O2; n = 1, 2) activated by carbon tetrabromide catalyzed intermolecular dehydration of primary and secondary alcohols with formation of the corresponding ethers.
Rhodium-catalyzed, efficient deutero- and tritiosilylation of carbonyl compounds from hydrosilanes and deuterium or tritium
Rubio, Miguel,Campos, Jesuus,Carmona, Ernesto
supporting information; experimental part, p. 5236 - 5239 (2011/12/15)
A cationic rhodium compound which is an active catalyst for both the hydrogen isotope exchange in hydrosilanes and the hydrosilylation of carbonyl compounds permits, in a one-flask, two-step procedure, efficient deutero- and tritiosilylations using SiEt3H under D2 (0.5 bar) or T2, at low catalyst loadings (0.1-0.5 mol %).
Ionic liquids - Advanced reaction media for organic synthesis
Ignat'ev, Nikolai V.,Schulte, Michael,Koppe, Karsten,Barthen, Peter,Zlotin, Sergei G.,Makhova, Nina N.,Sheremetev, Aleksei B.,Valente, Anabela A.
scheme or table, p. 1205 - 1216 (2011/09/16)
The advantages in the application of ionic liquids as reaction media in organic synthesis, i.e., in the preparation of chromane derivatives, substituted pyrazines, 4-aminofuran-2(5H)-ones, or in bromination of Levulinic acid or dehydration of alcohols, saccharides, and polysaccharides, have been demonstrated on several examples. Ionic liquids with Bronsted acidity have been shown to possess catalytic activity and provide access to convenient technologies for the preparation of various useful compounds. Copyright Merck KGaA.
DEHYDRATION OF ALCOHOLS TO GIVE ALKENES OR ETHERS
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Page/Page column 9, (2009/04/24)
The present invention relates to a process for the dehydration of alcohols, polyalcohols or alcoholates having at least one CH group in the α-position to the alcoholate or alcohol function to give alcenes or ethers, where the dehydration is carried out in ionic liquids of the general formula K+A?.
High-efficiency conversion of trimethylsilyl ethers to their corresponding ethers using carbon-based solid acid as a new catalyst in heterogeneous mixtures
Shokrollahi, Arash,Zali, Abbas,Pouretedal, Hamid Reza
, p. 371 - 375 (2008/04/01)
Carbon-based solid acid was used as a new catalyst for conversion of trimethylsilyl ethers to their corresponding ethers in heterogeneous mixtures. The experiments were done moderately at room temperature, and high yields in suitable times were obtained under these conditions. Copyright Taylor & Francis Group, LLC.
