- Breaking C-O Bonds with Uranium: Uranyl Complexes as Selective Catalysts in the Hydrosilylation of Aldehydes
-
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
-
p. 9025 - 9033
(2019/10/02)
-
- Silver/NBS-Catalyzed Synthesis of α-Alkylated Aryl Ketones from Internal Alkynes and Benzyl Alcohols via Ether Intermediates
-
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
-
supporting information
p. 5583 - 5586
(2018/09/21)
-
- Indium-catalyzed reductive esterification of a carboxylic acid: Sequential preparation of an ester and symmetrical ether
-
An unprecedented reductive dimerization of two carboxylic acids to produce ester derivatives by a combination catalyst involving InBr3 and sulfuric acid is described. A sequential conversion of the in-situ formed ester to a symmetrical ether by indium-catalyzed deoxygenation of the ester with a hydrosilane in the same pot was also demonstrated. Copyright
- Sakai, Norio,Usui, Yuta,Ikeda, Reiko,Konakahara, Takeo
-
supporting information; experimental part
p. 3397 - 3401
(2012/02/02)
-
- Rhodium-catalyzed, efficient deutero- and tritiosilylation of carbonyl compounds from hydrosilanes and deuterium or tritium
-
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 %).
- Rubio, Miguel,Campos, Jesuus,Carmona, Ernesto
-
supporting information; experimental part
p. 5236 - 5239
(2011/12/15)
-
- Aminodifluorosulfinium salts: Selective fluorination reagents with enhanced thermal stability and ease of handling
-
Diethylaminodifluorosulfinium tetrafluoroborate (XtalFluor-E) and morpholinodifluorosulfinium tetrafluoroborate (XtalFluor-M) are crystalline fluorinating agents that are more easily handled and significantly more stable than Deoxo-Fluor, DAST, and their analogues. These reagents can be prepared in a safer and more cost-efficient manner by avoiding the laborious and hazardous distillation of dialkylaminosulfur trifluorides. Unlike DAST, Deoxo-Fluor, and Fluolead, XtalFluor reagents do not generate highly corrosive free-HF and therefore can be used in standard borosilicate vessels. When used in conjunction with promoters such as Et3N3HF, Et3N2HF, or DBU, XtalFluor reagents effectively convert alcohols to alkyl fluorides and carbonyls to gem-difluorides. These reagents are typically more selective than DAST and Deoxo-Fluor and exhibit superior performance by providing significantly less elimination side products.
- Lheureux, Alexandre,Beaulieu, Francis,Bennett, Christopher,Bill, David R.,Clayton, Simon,Laflamme, Franois,Mirmehrabi, Mahmoud,Tadayon, Sam,Tovell, David,Couturier, Michel
-
experimental part
p. 3401 - 3411
(2010/07/07)
-
- Reduction of esters to ethers utilizing the powerful lewis acid BF 2OTf·OEt2
-
The direct reduction of esters to their corresponding ethers has been achieved using the Lewis acid BF2OTf·OEt2 generated via anionic redistribution between TMSOTf and BF3·OEt 2 with triethylsilane acting as the
- Morra, Nicholas A.,Pagenkopf, Brian L.
-
p. 511 - 514
(2008/12/21)
-
- Iron(III) chloride-catalyzed reductive etherification of carbonyl compounds with alcohols
-
A facile reductive etherification of carbonyl compounds can be performed by the reaction with alcohols and triethylsilane catalyzed by iron(III) chloride. The corresponding alkyl ethers are obtained in good to excellent yields under mild reaction conditions. Copyright
- Iwanami, Katsuyuki,Yano, Kentaro,Oriyama, Takeshi
-
-
- Multipolymer solution-phase reactions: Application to the mitsunobu reaction
-
The realization of the first polymer-on-polymer Mitsunobu reaction, in which a polymeric phosphine is used simultaneously with a polymeric azodicarboxylate, is reported. This strategy employs the use of soluble oligomers generated from ring-opening methathesis polymerization. 31P NMR analysis revealed that the two polymers were interacting to generate the Mitsunobu products. Application to several substrates, as well as comparison experiments with other polymeric reagents, is described. Copyright
- Harned, Andrew M.,He, Helen Song,Toy, Patrick H.,Flynn, Daniel L.,Hanson, Paul R.
-
-
- Bismuth trichloride catalyzed efficient reductive etherification of carbonyl compounds with alcohols: A novel method for preparation of symmetrical and unsymmetrical ethers
-
The reductive homocoupling of a carbonyl compound and heterocoupling of a carbonyl compound with a non-protected alcohol were both effected smoothly at room temperature with triethylsilane in the presence of a catalytic amount of bismuth trichloride to afford the corresponding ethers in good yields.
- Wada, Makoto,Nagayama, Sonoe,Mizutani, Kaori,Hiroi, Ryoichi,Miyoshi, Norikazu
-
p. 248 - 249
(2007/10/03)
-
- Lewis acid-catalyzed reductive etherification of carbonyl compounds with alkoxyhydrosilanes
-
The TMSI-catalyzed reaction of aldehydes and ketones with alkoxydimethylsilanes gave unsymmetrical ethers in good to high yields. This reductive etherification is superior to the conventional method using two kinds of silicon reagents in terms of atom eff
- Miura, Katsukiyo,Ootsuka, Kazunori,Suda, Shuntaro,Nishikori, Hisashi,Hosomi, Akira
-
p. 313 - 315
(2007/10/03)
-