31857-89-3Relevant articles and documents
Ru-containing polyoxometalate fabricated on graphene oxide: Preparation, characterization and catalytic activity
Ma, Zhiyuan,Yu, Tian,Bi, Lihua
, p. 16 - 22 (2019)
Polyoxometalates (POMs) with remarkable redox characteristics and good stability are considered as versatile catalysts, meanwhile graphene oxide (GO) with a layered structure and myriad oxygen atoms on its surface is also good catalyst. Thus their combination will have the synergistically enhanced effect on the catalytic performance and the reusability of the heterogeneous catalysts. Here, an environmentally-friendly heterogeneous catalyst (GO/PEI/RuPW10) was prepared by fabricating [(γ-PW10O36)2Ru4O5(OH)(H2O)4]9- (RuPW10) on the surface of GO functionalized by polyethylenimine (PEI). Further, this catalyst was applied to n-tetradecane oxidation using air as the oxidant. The results showed that 4.73% RuPW10 loaded catalyst exhibits high conversion (50.45%) of n-tetradecane under the optimized reaction condition. A recyclability test suggested that this catalyst can be reused up to five times without significant changes for the conversion of n-tetradecane. As a result, due to the high conversion, better stability and reusability, immobilizing POMs onto the surface of GO modified by PEI is one of the effective means to develop heterogeneous catalysts.
A new organo-ruthenium substituted tungstotellurate: Synthesis, structural characterization and catalytic properties
Zheng, Da-Ming,Wang, Rui-Qiang,Du, Yu,Hou, Guang-Feng,Wu, Li-Xin,Bi, Li-Hua
, p. 8829 - 8836 (2016/10/11)
Reaction of [RuC6H6Cl2]2 with TeO2 and Na2WO4·2H2O in aqueous solution (pH 4.7) yielded a novel organo-ruthenium supported tungstotellurate polyanion, [Te2W20O70(RuC6H6)2]8- (Ru-1), which is composed of two [RuC6H6]2+ units linked to a [Te2W20O70]12- fragment through Ru-O(W) bonds resulting in an assembly with idealized C2h symmetry. Furthermore, the polyanion Ru-1 was anchored on 3-aminopropyltriethoxysilane (apts)-modified SBA-15 to prepare new catalysts (SBA-15-apts-Ru-1) containing different amounts of Ru-1, which were characterized using powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N2-adsorption measurement and Fourier transform infrared reflectance (FT-IR) spectroscopy. Finally, the catalytic activity of SBA-15-apts-Ru-1 was evaluated for the aerobic oxidation of n-tetradecane using air as the oxidant in the absence of any additives or solvents. In addition, the optimum catalytic reaction conditions were also determined.
Chemoselective Ketone Synthesis by the Addition of Organometallics to N-Acylazetidines
Liu, Chengwei,Achtenhagen, Marcel,Szostak, Michal
, p. 2375 - 2378 (2016/06/09)
A general and highly chemoselective method for the synthesis of ketones by the addition of organometallics to N-acylazetidines via stable tetrahedral intermediates is reported for the first time. The transformation is characterized by its wide substrate scope and exquisite selectivity for the ketone products even when a large excess of nucleophilic reagents is used. Even of broader interest is the use of N-acylazetidines as bench-stable, readily available amide acylating reagents, in which the reactivity is controlled by amide pyramidalization and strain of the four-membered ring to afford synthetically valuable building blocks.
Hydrogen transfer type oxidation of alcohols by rhodium and ruthenium catalyst under microwave irradiation
Takahashi, Masaaki,Oshima, Koichiro,Matsubara, Seijiro
, p. 9201 - 9204 (2007/10/03)
Secondary alcohols were converted into the corresponding ketones by methyl acrylate and rhodium catalyst efficiently under microwave irradiation. Treatment of primary alcohols with the same condition resulted in the recovery of the starting materials. Primary alcohols were converted into aldehydes by hydrogen transfer reaction using methyl vinyl ketone and ruthenium catalyst under microwave irradiation.
Cu-catalyzed alkylation of Grignard reagents: A new efficient procedure
Cahiez, Gérard,Chaboche, Christophe,Jézéquel, Michelle
, p. 2733 - 2737 (2007/10/03)
The presence of NMP (4-9 equiv.) clearly improves the yield and the chemoselectivity of the Cu-catalyzed alkylation of organomagnesium reagents. Thus, secondary and tertiary alkylmagnesium chlorides were used successfully for the first time in such a reaction and ester, amide, nitrile or keto groups are tolerated. The procedure is cheap, environmentally friendly and very easy to carry out (1-3% Li2CuCl4 or CuCl, THF, 20°C). It is an interesting alternative to the classical alkylation of organocuprates reagents. (C) 2000 Published by Elsevier Science Ltd.
Preparation of ketones via the palladium-catalyzed cross-coupling of acid chlorides with trialkylboranes
Kabalka, George W.,Malladi, Rama R.,Tejedor, David,Kelley, Shane
, p. 999 - 1001 (2007/10/03)
Trialkylboranes react with acid chlorides in the presence of palladium to generate alkyl and aryl ketones in good yields. (C) 2000 Elsevier Science Ltd.
Hyperfine Structures of Doxyl-Labeled n-Alkyl Chains by NMR and EPR
Bales, Barney L.,Mareno, Donna,Harris, Francis L.
, p. 37 - 53 (2007/10/02)
The proton hyperfine coupling constants in a series of n-alkyl chains with a doxyl group attached at various points from the end of the chain have been measured by NMR and EPR spectroscopies.The hyperfine structure shows no further change when the attachment point is four or more carbon-carbon bonds from the end of the chain.The high resolution afforded by 500 MHz NMR reveals small magnetic inequivalencies in the chain methylene hyperfine coupling constants located at the same distance from the attachment point.Protons in the same chain methylene group are shown to have different hyperfine coupling constants while protons on different chain methylene groups, symmetrically placed with respect to attachment point, are the same, in every case except one.EPR spectra simulated from hyperfine coupling constants derived from NMR are in excellent agreement with experiment.Inhomogeneous EPR line broadening is found to be in excellent agreement with a previously derived universal hyperfine pattern (B.L.Bales, in "Biological Magnetic Resonance" (L.J.Berliner and J.Reuben, Eds.), Vol. 8, p. 77, Plenum, New York, 1989), so no new correction procedures are necessary.Strategies for selectively deuterating n-alkyl spin probes are developed and compared with some results taken from the literature.Deuterating the chain methylene groups two to three carbon-carbon bonds from the attachment point is necessary for the maximum gain in resolution and sensitivity.
Tetrahydrofolate Coenzyme Models: Synthesis of Tetrahydroimidazoisoquinolines and Tetrahydroimidazoquinolines
Jones, Raymond C. F.,Smallridge, Mark J.,Chapleo, Christopher B.
, p. 385 - 391 (2007/10/02)
The new dihydroimidazoles 3-methyl-1,5,6,10b-tetrahydroimidazoisoquinoline and 1-methyl-3,3a,4,5-tetrahydroimidazoquinoline are efficiently and conveniently prepared from isoquinoline and quinoline, via 1-aminomethyl-1,2,3,4-tetrahydroisoquinoline and 2-aminomethyl-1,2,3,4-tetrahydroquinoline, respectively.Deprotonation of the fused dihydroimidazoles at the methyl substituent leads to homologation via C-alkylation, C-acylation, or C-phosphonylation-condensation.The properties of the tetrahydroimidazoisoquinolines and tetrahydroimidazoquinolines towards reducing agents mirror those of monocyclic dihydroimidazoles, affording aminomethyl-isoquinolines and -quinolines, respectively.
Nucleophilic Addition to 4,5-Dihydroimidazoles: A Ketone Synthesis via Tetrahydrofolate Coenzyme Models
Anderson, Michael W.,Jones, Raymond C.F.
, p. 1995 - 1998 (2007/10/02)
1-Benzyl-2-alkyl-3-methyl-4,5-dihydroimidazolium salts with Grignard reagents give addition products that are hydrolysed to ketones; 4,5-dihydroimidazoles and 4,5-dihydroimidazolium salts with hydride reagents afford N-alkylated ethane-1,2-diamines.
