- Palladium-catalyzed β-acyloxylation of simple amide via sp3 C-H activation
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β-Acyloxy amides are prepared in moderate to high yields by palladium-catalyzed acyloxylation of primary sp3 C-H bonds from simple amides without any special directing group. A catalytic system of Pd(OAc)2/CF3CO2H/ K2S2O8 is available to various amides with N-substituted by linear alkanes, cyclic alkanes, and electron-deficient benzyl compounds in this reaction. Acyloxylated products could be transformed easily to the corresponding β-hydroxy amides.
- Zhou, Lihong,Lu, Wenjun
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supporting information
p. 508 - 511
(2014/04/03)
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- Solvent effect and reactivity trend in the aerobic oxidation of 1,3-propanediols over gold supported on titania: Nmr diffusion and relaxation studies
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In recent work, it was reported that changes in solvent composition, precisely the addition of water, significantly inhibits the catalytic activity of Au/TiO2 catalyst in the aerobic oxidation of 1,4-butanediol in methanol due to changes in diffusion and adsorption properties of the reactant. In order to understand whether the inhibition mechanism of water on diol oxidation in methanol is generally valid, the solvent effect on the aerobic catalytic oxidation of 1,3-propanediol and its two methyl-substituted homologues, 2-methyl-1,3-propanediol and 2,2-dimethyl-1,3-propanediol, over a Au/TiO2 catalyst has been studied here using conventional catalytic reaction monitoring in combination with pulsed-field gradient nuclear magnetic resonance (PFG-NMR) diffusion and NMR relaxation time measurements. Diol conversion is significantly lower when water is present in the initial diol/methanol mixture. A reactivity trend within the group of diols was also observed. Combined NMR diffusion and relaxation time measurements suggest that molecular diffusion and, in particular, the relative strength of diol adsorption, are important factors in determining the conversion. These results highlight NMR diffusion and relaxation techniques as novel, non-invasive characterisation tools for catalytic materials, which complement conventional reaction data. In solvent company: The solvent effect on the aerobic catalytic oxidation of 1,3-propanediol and its two methyl-substituted homologues, 2-methyl-1,3-propanediol and 2,2-dimethyl-1,3-propanediol, over a Au/TiO 2 catalyst has been studied. The results show that diol conversion is significantly lower when water is present in the initial diol/methanol mixture. A reactivity trend within the group of diols was also observed. Copyright
- D'Agostino, Carmine,Kotionova, Tatyana,Mitchell, Jonathan,Miedziak, Peter J.,Knight, David W.,Taylor, Stuart H.,Hutchings, Graham J.,Gladden, Lynn F.,Mantle, Mick D.
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p. 11725 - 11732
(2013/09/12)
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- Oxidative esterification of homologous 1,3-propanediols
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The oxidative esterification of a homologous series of diols (1,3-propanediol,2-methyl-propanediol and 2,2-dimethyl-1,3-propanediol) with methanol has been investigated using titania-supported gold, palladium and gold-palladium catalysts using molecular oxygen. The gold-palladium catalysts showed the highest activity and 1,3-propanediol was the most reactive while the additional methyl groups decreased the reactivity. However, it is possible to achieve high selectivity to methyl 3-hydroxypropionate and 2-methyl-3- hydroxyisobutyrate by mono-oxidations. Graphical Abstract: [Figure not available: see fulltext.]
- Kotionova, Tatyana,Lee, Christopher,Miedziak, Peter J.,Dummer, Nicholas F.,Willock, David J.,Carley, Albert F.,Morgan, David J.,Knight, David W.,Taylor, Stuart H.,Hutchings, Graham J.
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p. 1114 - 1120
(2012/10/29)
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- Cu(I)-catalyzed oxidative cyclization of alkynyl oxiranes and oxetanes
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In the presence of a Cu(I) catalyst and a pyridine oxide, alkynyl oxiranes and oxetanes can be converted into functionalized five- or six-membered α,β-unsaturated lactones or dihydrofuranaldehydes. This new oxidative cyclization is proposed to proceed via an unusual allenyloxypyridinium intermediate.
- Gronnier, Colombe,Kramer, Soren,Odabachian, Yann,Gagosz, Fabien
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supporting information; experimental part
p. 828 - 831
(2012/03/07)
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- Bioactive constituents from chinese natural medicines. XXXI.1 hepatoprotective principles from sinocrassula indica: Structures of sinocrassosides A8, A9, A10, A11, and A12
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The methanolic extract from the whole plant of Sinocrassula indica (Crassulaceae) was found to show hepatoprotective effect on D-galactosamineinduced cytotoxicity in primary cultured mouse hepatocytes. From the methanolic extract, five new acylated flavon
- Ninomiya, Kiyofumi,Morikawa, Toshio,Xie, Haihui,Matsuda, Hisashi,Yoshikawa, Masayuki
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experimental part
p. 1983 - 1995
(2009/04/06)
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