38460-98-9Relevant articles and documents
Bis(pertrifluoromethylcatecholato)silane: Extreme Lewis Acidity Broadens the Catalytic Portfolio of Silicon
Thorwart, Thadd?us,Roth, Daniel,Greb, Lutz
supporting information, p. 10422 - 10427 (2021/05/27)
Given its earth abundance, silicon is ideal for constructing Lewis acids of use in catalysis or materials science. Neutral silanes were limited to moderate Lewis acidity, until halogenated catecholato ligands provoked a significant boost. However, catalytic applications of bis(perhalocatecholato)silanes were suffering from very poor solubility and unknown deactivation pathways. In this work, the novel per(trifluoromethyl)catechol, H2catCF3, and adducts of its silicon complex Si(catCF3)2 (1) are described. According to the computed fluoride ion affinity, 1 ranks among the strongest neutral Lewis acids currently accessible in the condensed phase. The improved robustness and affinity of 1 enable deoxygenations of aldehydes, ketones, amides, or phosphine oxides, and a carbonyl-olefin metathesis. All those transformations have never been catalyzed by a neutral silane. Attempts to obtain donor-free 1 attest to the extreme Lewis acidity by stabilizing adducts with even the weakest donors, such as benzophenone or hexaethyl disiloxane.
Preparation of a platinum nanoparticle catalyst located near photocatalyst titanium oxide and its catalytic activity to convert benzyl alcohols to the corresponding ethers
Akiyama, Toshiki,Arisawa, Mitsuiro,Harada, Kazuo,Honma, Tetsuo,Naka, Hiroshi,Saito, Susumu,Wada, Yuki
, p. 22230 - 22237 (2021/07/02)
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.
Method for synthesizing ether by catalyzing alcohol through trimethyl halosilane
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Paragraph 0039-0042, (2020/12/29)
The invention discloses a method for synthesizing ether by catalyzing alcohol through trimethyl halosilane. According to the method, under the conditions of air or nitrogen atmosphere, no solvent andno transition metal catalyst, an alcohol compound is directly used as a raw material, trimethyl halosilane is used as a catalyst, and symmetric or asymmetric ether is synthesized through one-step selective dehydration reaction. According to the method, the use of strong acid, strong base and organic primary halides with high toxicity, instability and higher price is avoided, the synthesis steps are shortened, the synthesis efficiency is improved, the reaction has good selectivity, and a target ether product can be obtained preferentially.
Breaking C-O Bonds with Uranium: Uranyl Complexes as Selective Catalysts in the Hydrosilylation of Aldehydes
Monsigny, Louis,Thuéry, Pierre,Berthet, Jean-Claude,Cantat, Thibault
, p. 9025 - 9033 (2019/10/02)
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.
Nickel Catalyzed Intermolecular Carbonyl Addition of Aryl Halide
Ishida, Seima,Suzuki, Hiroyuki,Uchida, Seiichiro,Yamaguchi, Eiji,Itoh, Akichika
supporting information, p. 7483 - 7487 (2019/12/11)
In this study, we develop a nickel-catalyzed carbonyl arylation reaction employing aldehydes with aryl and allyl halides. Various aryl, α,β-unsaturated aldehyde and aliphatic aldehydes can be converted into their corresponding secondary alcohols in moderate-to-high yields. In addition, we extended this approach to develop an asymmetric reductive coupling reaction that combines nickel salts with chiral bisoxazoline ligands to give secondary alcohols with moderate enantioselectivity.
Aryl Boronic Acid Catalysed Dehydrative Substitution of Benzylic Alcohols for C?O Bond Formation
Estopi?á-Durán, Susana,Donnelly, Liam J.,Mclean, Euan B.,Hockin, Bryony M.,Slawin, Alexandra M. Z.,Taylor, James E.
, p. 3950 - 3956 (2019/02/16)
A combination of pentafluorophenylboronic acid and oxalic acid catalyses the dehydrative substitution of benzylic alcohols with a second alcohol to form new C?O bonds. This method has been applied to the intermolecular substitution of benzylic alcohols to form symmetrical ethers, intramolecular cyclisations of diols to form aryl-substituted tetrahydrofuran and tetrahydropyran derivatives, and intermolecular crossed-etherification reactions between two different alcohols. Mechanistic control experiments have identified a potential catalytic intermediate formed between the aryl boronic acid and oxalic acid.
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.
Reductive Etherification via Anion-Binding Catalysis
Zhao, Chenfei,Sojdak, Christopher A.,Myint, Wazo,Seidel, Daniel
supporting information, p. 10224 - 10227 (2017/08/10)
Reductive condensations of alcohols with aldehydes/ketones to generate ethers are catalyzed by a readily accessible thiourea organocatalyst that operates in combination with HCl. 1,1,3,3-tetramethyldisiloxane serves as a convenient reducing reagent. This strategy is applicable to challenging substrate combinations and exhibits functional group tolerance. Competing reductive homocoupling of the carbonyl component is suppressed.
Efficient carbon-supported heterogeneous molybdenum-dioxo catalyst for chemoselective reductive carbonyl coupling
Liu, Shengsi,Li, Jiaqi,Jurca, Titel,Stair, Peter C.,Lohr, Tracy L.,Marks, Tobin J.
, p. 2165 - 2169 (2017/07/22)
Reductive coupling of various carbonyl compounds to the corresponding symmetric ethers with dimethylphenylsilane is reported using a carbon-supported dioxo-molybdenum catalyst. The catalyst is air- and moisture-stable and can be easily separated from the reaction mixture for recycling. In addition, the catalyst is chemoselective, thus enabling the synthesis of functionalized ethers without requiring sacrificial ligands or protecting groups.
Ni(ii)-N′NN′ pincer complexes catalyzed dehydrogenation of primary alcohols to carboxylic acids and H2 accompanied by alcohol etherification
Luo, Qi,Dai, Zengjin,Luo, Qin,Jiang, Huan,Li, Hua,Zhang, Jing,Peng, Tianyou
, p. 2506 - 2511 (2017/07/22)
Acceptorless dehydrogenation of alcohols to carboxylic acid derivatives catalyzed by a transition metal complex is an important reaction in modern organic synthesis and catalysis, for which nickel complexes have rarely been developed. Herein we report three Ni(ii) complexes bearing pyridine-based N′NN′ type pincer ligands, which catalyze the acceptorless dehydrogenation of primary alcohols to carboxylic acids under anhyrous conditions. The complex [NiCl2(L3)] 3 (L3 = 2,6-bis(diethylaminomethyl)pyridine) displays the best catalytic reactivity, catalyzing the primary alcohols to carboxylic acids and H2 in good yields (40-90%). Further investigation reveals that an unexpected alcohol etherification occurs, which gives the second oxygen atom for the formation of the carboxylic acid. Our results give a thread for the design of new nickel complexes without phosphine and N-heterocycle carbene ligands for the acceptorless oxidation of alcohols.
