- Preparation of a platinum nanoparticle catalyst located near photocatalyst titanium oxide and its catalytic activity to convert benzyl alcohols to the corresponding ethers
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A novel platinum nanoparticle catalyst closely located near the surface of titanium oxide, PtNP/TiO2, has been prepared. This catalyst has both the properties of a photocatalyst and a metal nanoparticle catalyst, and acquired environmentally friendly catalytic activity, which cannot be achieved by just one of these catalysts, to afford ethers from benzyl alcohols under the wavelength of 420 nm.
- Akiyama, Toshiki,Arisawa, Mitsuiro,Harada, Kazuo,Honma, Tetsuo,Naka, Hiroshi,Saito, Susumu,Wada, Yuki
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p. 22230 - 22237
(2021/07/02)
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- Breaking C-O Bonds with Uranium: Uranyl Complexes as Selective Catalysts in the Hydrosilylation of Aldehydes
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We report herein the possibility to perform the hydrosilylation of carbonyls using actinide complexes as catalysts. While complexes of the uranyl ion [UO2]2+ have been poorly considered in catalysis, we show the potentialities of the Lewis acid [UO2(OTf)2] (1) in the catalytic hydrosilylation of a series of aldehydes. [UO2(OTf)2] proved to be a very active catalyst affording distinct reduction products depending on the nature of the reductant. With Et3SiH, a number of aliphatic and aromatic aldehydes are reduced into symmetric ethers, while iPr3SiH yielded silylated alcohols. Studies of the reaction mechanism led to the isolation of aldehyde/uranyl complexes, [UO2(OTf)2(4-Me2N-PhCHO)3], [UO2(μ-κ2-OTf)2(PhCHO)]n, and [UO2(μ-κ2-OTf)(κ1-OTf)(PhCHO)2]2, which have been fully characterized by NMR, IR, and single-crystal X-ray diffraction.
- Monsigny, Louis,Thuéry, Pierre,Berthet, Jean-Claude,Cantat, Thibault
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p. 9025 - 9033
(2019/10/02)
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- A General Catalytic Method for Highly Cost- and Atom-Efficient Nucleophilic Substitutions
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A general formamide-catalyzed protocol for the efficient transformation of alcohols into alkyl chlorides, which is promoted by substoichiometric amounts (down to 34 mol %) of inexpensive trichlorotriazine (TCT), is introduced. This is the first example of a TCT-mediated dihydroxychlorination of an OH-containing substrate (e.g., alcohols and carboxylic acids) in which all three chlorine atoms of TCT are transferred to the starting material. The consequently enhanced atom economy facilitates a significantly improved waste balance (E-factors down to 4), cost efficiency, and scalability (>50 g). Furthermore, the current procedure is distinguished by high levels of functional-group compatibility and stereoselectivity, as only weakly acidic cyanuric acid is released as exclusive byproduct. Finally, a one-pot protocol for the preparation of amines, azides, ethers, and sulfides enabled the synthesis of the drug rivastigmine with twofold SN2 inversion, which demonstrates the high practical value of the presented method.
- Huy, Peter H.,Filbrich, Isabel
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supporting information
p. 7410 - 7416
(2018/04/30)
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- Silver/NBS-Catalyzed Synthesis of α-Alkylated Aryl Ketones from Internal Alkynes and Benzyl Alcohols via Ether Intermediates
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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.
- Chun, Supill,Chung, Young Keun
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supporting information
p. 5583 - 5586
(2018/09/21)
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- Synthesis of ethers from carbonyl compounds by reductive etherification catalyzed by iron(III) and silyl chloride
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A simple iron- and silyl chloride catalyzed method for the preparation of symmetrical and nonsymmetrical ethers is presented. Various aldehydes and ketones were reductively etherified by using triethylsilane as a reducing agent in the presence of 2 mol% of iron(III) oxo acetate and 8 mol% of chloro(trimethyl)silane. The reactions can be carried out at ambient temperatures and pressures with ethyl acetate as the solvent.
- Savela, Risto,Leino, Reko
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p. 1749 - 1760
(2015/06/16)
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- Reductive coupling reaction of aldehydes using indium(III) triflate as the catalyst
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A reductive coupling reaction was effectively developed to convert an aldehyde to its symmetrical ether. The successful reactions required Et 3SiH and CH2Cl2 as the suitable solvent in the presence of a catalytic amount of In(OTf)3. Various aldehydes were subjected to the method, and each afforded the expected ethers in good to excellent yields.
- Mineno, Tomoko,Tsukagoshi, Rie,Iijima, Tsubasa,Watanabe, Kazuki,Miyashita, Hiroyuki,Yoshimitsu, Hitoshi
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p. 3765 - 3767
(2014/07/07)
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- Silica chloride and boron sulfonic acid as solid acid catalysts in preparation of ethers and esters under solvent-free condition
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Boron sulfonic acid was easily prepared from the reaction of boric acid and chlorosulfonic acid under solvent free condition. The prepared solid acid was supported on silica gel by simple grinding and used as efficient solid acid catalyst in the preparation of ethers from the aliphatic and aromatic alcohols. The ethers were prepared in high isolated yields and in lesser times. Silica chloride was prepared by refluxing of silica gel in thionyl chloride. The obtained solid acid was efficiently used for the conditions of alcohols to the corresponding ethers and acetyl esters in less reaction time and in high isolated yields.
- Elham, Sedighinia,Mozhgan, Zahed Sargoli
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supporting information; experimental part
p. 1456 - 1458
(2012/01/06)
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- High-efficiency conversion of trimethylsilyl ethers to their corresponding ethers using carbon-based solid acid as a new catalyst in heterogeneous mixtures
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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.
- Shokrollahi, Arash,Zali, Abbas,Pouretedal, Hamid Reza
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p. 371 - 375
(2008/04/01)
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- A stereocontrolled approach to ethers with two α stereocentres
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The stereocontrolled synthesis of enantiomeric pairs of four ethers, in which the oxygen atom is flanked by two α stereocentres, has been achieved using a chiral base/arene chromium tricarbonyl activation approach. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Felstead, Robert,Gibson, Susan E.,Rooney, Aaron,Tse, Eric S. Y.
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experimental part
p. 4963 - 4971
(2009/08/07)
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- Silica Sulfuric Acid: An Efficient Catalyst for the Direct Conversion of Primary and Secondary Trimethylsilyl Ethers to their Corresponding Ethers under Mild and Heterogeneous Conditions
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Primary and secondary trimethylsilyl ethers were converted to their corresponding ethers in the presence silica sulfuric acid with good to excellent yields under mild and heterogeneous conditions.
- Zolfigol, Mohammad Ali,Mohammadpoor-Baltork, Iraj,Mirjalili, Bibi Fatemeh,Bamoniri, Abdolhamid
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p. 1877 - 1879
(2007/10/03)
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- The use of Nafion-H as an efficient catalyst for the direct conversion of primary and secondary trimethylsilyl ethers to their corresponding ethers under mild and heterogeneous conditions
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Primary and secondary trimethylsilyl ethers were converted to their corresponding ethers in the presence Nafion-H with good to excellent yields under mild and heterogeneous conditions.
- Zolfigol, Mohammad Ali,Mohammadpoor-Baltork, Iraj,Habibi, Davood,Mirjalili, BiBi Fatemeh,Bamoniri, Abdolhamid
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p. 8165 - 8167
(2007/10/03)
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- Silica sulfuric acid as an efficient reagent for the synthesis of symmetrical ethers under mild and heterogeneous conditions
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A mild and efficient method for the synthesis of symmetrical ethers using silica sulfuric acid is reported. All reactions are performed under compeletly heterogeneous conditions in good to high yields.
- Shirini, Farhad,Zolfigol, Mohammad Ali,Mohammadi, Kamal
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p. 2357 - 2361
(2007/10/03)
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- Water-Soluble Calixarenes as New Inverse Phase-Transfer Catalysts. Their Scope in Aqueous Biphasic Alkylations and Mechanistic Implications
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Alkylation reactions of active methylene compounds, alcohols and phenols with alkyl halides in aqueous NaOH solution can be carried out without the need for any added organic solvents in most cases. The water-soluble calix[n]arenes, which contain trimethylammoniomethyl groups on the upper rim, were used as inverse phase-transfer catalysts, resulting in the corresponding alkylated products in good to high yields. The scope of this methodology in aqueous biphasic alkylation reactions and the mechanistic implications are discussed.
- Shoichi, Shimizu,Suzuki, Takashi,Shirakawa, Seiji,Sasaki, Yasuyuki,Hirai, Choichiro
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p. 370 - 378
(2007/10/03)
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- Solid Superacid-Catalyzed Organic Synthesis. 4. Perfluorinated Resinsulfonic Acid (Nafion-H) Catalyzed Friedel-Crafts Benzylation of Benzene and Substituted Benzenes
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Nafion-H, a perfluorinated resinsulfonic acid, catalyzes Friedel-Crafts benzylation of benzene and substituted benzenes with benzyl alcohols under relatively mild experimental conditions.Reactions are clean, and water formed as a byproduct does not deactivate the catalyst.It was also found that this method is applicable to the intramolecular cycloalkylation and oligomerization of methoxybenzyl alcohols.
- Yamato, Takehiko,Hideshima, Chieko,Prakash, G. K. Surya,Olah, George A.
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p. 2089 - 2091
(2007/10/02)
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- The synthesis of aldehydes by means of a modified Rosenmund reduction of acid chlorides
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Aliphatic as well as aromatic acid chlorides are reduced smoothly into aldehydes at room temperature and atmospheric pressure by hydrogenation, using palladium on carbon as the catalyst, acetone or ethyl acetate as solvent and ethyldiisopropylamine as hydrogen chloride acceptor.The reaction has a high selectivity and under the conditions used, no over-reduction nor reduction of aromatic rings, of nitro and chloro substituents in benzoyl chlorides, or double bonds in cinnamoyl chlorides, was observed.The selectivity is probably the result of a combination of factors, such as selective adsorption of the acid chloride on the catalyst (with respect to the aldehyde) and partial poisoning of the catalyst surface by co-adsorption of ethyldiisopropylamine and its hydrochloride.
- Peters, J. A.,Bekkum, H. van
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