3459-80-1Relevant articles and documents
The influence of the acidity of ionic liquids on catalysis
Cui, Xinjiang,Zhang, Shiguo,Shi, Feng,Zhang, Qinghua,Ma, Xiangyuan,Lu, Liujin,Deng, Youquan
, p. 1043 - 1047 (2010)
Reactions performed in ionic liquids with BF4- as anion progress under strongly acidic conditions. The acidity of some air- and moisture-stable ionic liquids is explored and its effect on catalytic reactions is studied. The function of these ionic liquids in some traditional acid-catalyzed reactions is also tested, and the results merit a reconsideration of their influence on catalytic reactions and use in other applications.
Electrophilic Substitution in Pyrroles. Part 4. Hydrogen Exchange in Acid Solution
Alexander, Robert s.,Butler, Anthony R.
, p. 110 - 112 (1980)
Hydrogen exchange at the unsubstituted positions in 1,2,5-trimethyl- and 1,3,4-trimethyl-pyrrole in aqueous buffer has been examined.The two positions were found to be of similar reactivities.General acid catalysis was detected.No hydrogen exchange on the methyl groups of 2,3,4,5-tetramethylpyrrole, even in strong acid, was detected.The 13C n.m.r. spectrum of the tetramethylpyrrole was examined.
Zeolites Catalyze the Nazarov Reaction and the tert -Butylation of Alcohols by Stabilization of Carboxonium Intermediates
Blake, Finn,Leyva-Pérez, Antonio,Sanz-Navarro, Sergio,Tejeda-Serrano, María
, p. 2031 - 2037 (2020/07/14)
Zeolites are the most used catalysts worldwide in petrochemistry processes, with particular ability to stabilize carbocations. However, the use of zeolites in organic synthesis is still scarce. We show here that representative carboxonium-mediated organic
Hydrosilylation of carbonyl and carboxyl groups catalysed by Mn(i) complexes bearing triazole ligands
Martínez-Ferraté, Oriol,Chatterjee, Basujit,Werlé, Christophe,Leitner, Walter
, p. 6370 - 6378 (2019/11/20)
Manganese(i) complexes bearing triazole ligands are reported as catalysts for the hydrosilylation of carbonyl and carboxyl compounds. The desired reaction proceeds readily at 80 °C within 3 hours at catalyst loadings as low as 0.25 to 1 mol%. Hence, good to excellent yields of alcohols could be obtained for a wide range of substrates including ketones, esters, and carboxylic acids illustrating the versatility of the metal/ligand combination.
The Guanidine-Promoted Direct Synthesis of Open-Chained Carbonates
Shang, Yuhan,Zheng, Mai,Zhang, Haibo,Zhou, Xiaohai
, p. 933 - 938 (2019/09/30)
In order to reduce CO2 accumulation in the atmosphere, chemical fixation methodologies were developed and proved to be promising. In general, CO2 was turned into cyclic carbonates by cycloaddition with epoxides. However, the cyclic carbonates need to be converted into open-chained carbonates by transesterification for industrial usage, which results in wasted energy and materials. Herein, we report a process catalyzed by tetramethylguanidine (TMG) to afford linear carbonates directly. This process is greener and shows potential for industrial applications.
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.
Palladium on Carbon-Catalyzed Benzylic Methoxylation for Synthesis of Mixed Acetals and Orthoesters
Yasukawa, Naoki,Kanie, Takafumi,Kuwata, Marina,Monguchi, Yasunari,Sajiki, Hironao,Sawama, Yoshinari
supporting information, p. 10974 - 10977 (2017/08/22)
The palladium on carbon (Pd/C)-catalyzed direct methoxylation of the benzylic positions of linear benzyl and cyclic ether substrates proceeded in the presence of i-Pr2NEt under an oxygen atmosphere to give the corresponding mixed acetals. Cyclic acetal derivatives could also be converted into orthoesters. The present direct methoxylation via a carbon-hydrogen (C?H) functionalization can be accomplished using the easily-removed Pd/C and molecular oxygen as a green oxidant. The obtained mixed acetals were transformed into the corresponding ether products by chemoselective substitution of the methoxy group using a silyltriflate, 2,4,6-collidine, and a nucleophile. The orthoester derivative could also be transformed into the cyclic ketal under similar reaction conditions.
Auto-Tandem Catalysis with Frustrated Lewis Pairs for Reductive Etherification of Aldehydes and Ketones
Bakos, Mária,Gy?m?re, ádám,Domján, Attila,Soós, Tibor
supporting information, p. 5217 - 5221 (2017/04/27)
Herein we report that a single frustrated Lewis pair (FLP) catalyst can promote the reductive etherification of aldehydes and ketones. The reaction does not require an exogenous acid catalyst, but the combined action of FLP on H2, R-OH or H2O generates the required Br?nsted acid in a reversible, “turn on” manner. The method is not only a complementary metal-free reductive etherification, but also a niche procedure for ethers that would be either synthetically inconvenient or even intractable to access by alternative synthetic protocols.
METHOD FOR PRODUCING ASYMMETRIC ALKYL ETHER HAVING TERTIARY ALKYL GROUP
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Paragraph 0029, (2017/01/31)
PROBLEM TO BE SOLVED: To provide a method capable of obtaining an asymmetric alkyl ether having a tertiary alkyl group easily and industrially. SOLUTION: (1) There is provided a method for producing an asymmetric alkyl ether having a tertiary alkyl group by subjecting a tertiary alcohol and a primary alcohol or a secondary alcohol to a dehydration reaction using activated clay as a catalyst. (2) There is provided the method for producing an asymmetric alkyl ether having a tertiary alkyl group according to (1), where the tertiary alcohol is any one selected from the group consisting of tert-butanol, tert-amylalcohol and 1-adamantyl alcohol. SELECTED DRAWING: None COPYRIGHT: (C)2016,JPOandINPIT
Gold(I)-catalyzed synthesis of unsymmetrical ethers using alcohols as alkylating reagents
Liu, Yongxiang,Wang, Xiaoyu,Wang, Yanshi,Du, Chuan,Shi, Hui,Jin, Shengfei,Jiang, Chongguo,Xiao, Jianyong,Cheng, Maosheng
, p. 1029 - 1036 (2015/03/30)
A microwave-irradiated alcohol-protecting strategy based on gold catalysis utilizing benzyl alcohol, tert-butyl alcohol and triphenylmethanol as alkylating reagents has been developed. This protecting strategy has wide functional group tolerance with satisfactory yields for the majority of the selected alcohols. The mechanism of this transformation was probed with oxygen-18 isotope labelled alcohols assisted by GC-MS techniques and chemical kinetic experiments. This strategy provides an efficient, straightforward and alternative approach to the preparation of benzyl, tert-butyl and trityl ethers in organic synthesis.
