131-58-8Relevant academic research and scientific papers
Palladium-catalyzed C-H acylation of arenes using thioethers as directing groups
Xu, Bo,Liu, Wei,Kuang, Chunxiang
, p. 2576 - 2583 (2014)
A highly efficient protocol for regioselective synthesis of diaryl ketones by palladium-catalyzed direct acylation of arenes using thioethers as directing groups is reported. The possible pathway of direct acylation between thioethers and α-oxocarboxylic acids is discussed. The direct acylation of thioethers via Pd-catalyzed C-H bond activation was described. Copyright
Structural changes in concentrated solutions of alkali metal monosubstituted benzophenone radical anions as deduced front1H NMR measurements
Micha-Screttas, Maria,Heropoulos, Georgios A.,Steele, Barry R.
, p. 586 - 592 (2001)
The radical anions of monosubstituted benzophenones (including 2-, 3- and 4-methyl-, 4-tert-butyl- and 4-phenylbenzophenone) with lithium, sodium and potassium as countercations in tetrahydrofuran (THF) were studied by paramagnetic solvent 1H NMR shift measurements in the concentration range ca 0.1-1.0 M. In addition to the cation effects, marked positional isomer and substituent effects were found for (1) molar paramagnetism, (2) magnetic state, (3) solubility, (4) structural stability with respect to concentration or addition of cosolvents and (5) rapidity of attainment of their equilibrium structure. The major conclusions which can be drawn are (a) the solvation behavior of the countercation is governed by the anion, (b) an alkyl group in the 4-position makes the structure of the lithium and sodium monosubstituted benzophenone radical anions concentration dependent and (c) in most cases, alkali metal aromatic ketone radical anions generated by electron transfer from the corresponding naphthalene radical anion attain their equilibrium structure rapidly. The data are interpreted on the basis of the involvement of spin-triplet interactions within 'dimers' or higher clusters. Copyright
Application of mobilized gold nanoparticles as sole catalyst for the oxidation of secondary alcohols into ketones
Kidwai, Mazaahir,Bhardwaj, Saurav
, p. 1 - 4 (2010)
Oxidation of alcohols into corresponding ketones is efficiently catalyzed by heterogeneous gold nanoparticles. Use of H2O2 instead of O2 (g) is the main feature of our methodology since maintaining the required pressure of O2 (g) at elevated temperature is not easy. The reaction does not require any co-catalyst. After completion of the reaction, the catalyst could be recovered by centrifugation and reused several times with only a slight decrease in activity. Thus our present protocol, which is comprised of green reagent, solvent and catalyst, is completely clean.
Structural characterization of bismuth(III) and antimony(III) chlorotriflates: Key intermediates in catalytic Friedel-Crafts transformations
Mazieres, Stephane,Le Roux, Christophe,Peyronneau, Magali,Gornitzka, Heinz,Roques, Nicolas
, p. 2823 - 2826 (2004)
Chlorotriflates of antimony and bismuth ClnM(OSO 2CF3)3-n (n = 1 or 2) are believed to be metallic intermediates of major importance in Friedel-Crafts reactions that use Bi(OSO2CF3)3, Sb(OSO2CF 3)3, the systems BiCl3/CF3SO 2OH or SbCl3/CF3SO2OH as catalysts. Unknown until now, the compounds ClBi(OSO2CF3)2 (1) and Cl2Sb(OSO2CF3) (2) have been synthesized by reaction of MCl3 (M = Bi, Sb) with triflic acid. After crystallization from THF, 1 and 2 were investigated in the solid state by X-ray crystallography. Their use as catalysts in benzoylation of toluene, acylation of m-xylene, and sulfonylation of toluene led to conclusive results, thus giving weight to their key role as intermediates in Friedel-Crafts reactions. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
Palladium NCN and CNC pincer complexes as exceptionally active catalysts for aerobic oxidation in sustainable media
Urgoitia, Garazi,Sanmartin, Raul,Herrero, Maria Teresa,Dominguez, Esther
, p. 2161 - 2166 (2011)
The oxidation of secondary benzyl alcohols is catalyzed by two palladacycles at atmospheric pressure in PEG-400, a sustainable reaction media. Recycling of the active catalytic species is performed up to the 5th run, and catalyst loadings decreased down to 10-8 mol%, thus achieving unprecedented TON and TOF values. In addition, the same conditions proved to be effective for the aerobic oxidation of benzyl methylene compounds, a scarcely explored process by palladium catalysts.
Towards applications of metal-organic frameworks in catalysis: Friedel-Crafts acylation reaction over IRMOF-8 as an efficient heterogeneous catalyst
Nguyen, Lien T.L.,Nguyen, Chi V.,Dang, Giao H.,Le, Ky K.A.,Phan, Nam T.S.
, p. 28 - 35 (2011)
A highly porous metal-organic framework (IRMOF-8) was synthesized by a solvothermal method, and used as an efficient heterogeneous catalyst for the Friedel-Crafts acylation reaction. The solid catalyst was characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), atomic absorption spectrophotometry (AAS), and nitrogen physisorption measurements. High conversions were achieved in the presence of a catalytic amount of the IRMOF-8 (1-5 mol%) without the need for an inert atmosphere. The solid catalyst could be facilely separated from the reaction mixture by simple centrifugation, and could be reused without a significant degradation in catalytic activity. No contribution from homogeneous catalysis of active acid species leaching into the reaction solution was detected.
N-Acylsuccinimides: Twist-controlled, acyl-transfer reagents in Suzuki-Miyaura cross-coupling by N-C amide bond activation
Osumi, Yuki,Liu, Chengwei,Szostak, Michal
, p. 8867 - 8871 (2017)
The palladium-catalyzed Suzuki-Miyaura cross-coupling of N-acylsuccinimides as versatile acyl-transfer reagents via selective amide N-C bond cleavage is reported. The method is user-friendly since it employs commercially-available, air-stable reagents and catalysts. The cross-coupling is enabled by half-twist of the amide bond in N-acylsuccinimides. These highly effective, crystalline acyl-transfer reagents present major advantages over perpendicularly twisted N-acylglutarimides, including low price of the succinimide activating ring, selective metal insertion under redox neutral conditions and high stability of the amide bond towards reaction conditions. Mechanistic studies indicate that oxidative addition is the rate limiting step in this widely applicable protocol.
Sulfated fibrous ZrO2/Al2O3 core and shell nanocomposites: A novel strong acid catalyst with hierarchically macro-mesoporous nanostructure
Liu, Erming,Locke, Ashley J.,Frost, Ray L.,Martens, Wayde N.
, p. 95 - 105 (2012)
A series of solid strong acid catalysts were synthesized from fibrous ZrO2/Al2O3 core and shell nanocomposites. In this series, the zirconium molar percentage was varied from 2% to 50%. The ZrO2/Al2O3 nanocomposites and their solid strong acid counterparts were characterised by a variety of techniques including 27Al magic angle spinning nuclear magnetic resonance (MAS-NMR), scanned electronic microscopy (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption and infrared emission spectroscopy (IES). NMR results show that the interaction between zirconia species and alumina strongly correlates with pentacoordinated aluminium sites. This can also be detected by the change in binding energy of the 3d electrons of the zirconium. The acidity of the obtained solid acids was tested by using them as catalysts for the benzoylation of toluene. It was found that a sample with a 50% zirconium molar percentage possessed the highest surface acidity equalling that of pristine sulfated zirconia despite the reduced mass of zirconia.
Diaryl ketone synthesis by [RuHCl(CO)(PPh3)3]- catalyzed coupling reaction of arylboronic acids with aryl aldehydes
Fukuyama, Takahide,Okamoto, Hiromi,Ryu, Ilhyong
, p. 1453 - 1455 (2011)
[RuHCl(CO)(PPh3)3] was found to be an efficient catalyst for the coupling reaction of arylboronic acids with aryl aldehydes. The reaction proceeded smoothly in the presence of K2CO3 and H2O to give diaryl ketones in good yields. Diaryl ketones were obtained from primarily formed alcohols via Rucatalyzed transfer hydrogenation reaction.
Bismuth(III) bis(trifluoromethanesulfonyl)amide
Picot, Alexandre,Repichet, Sigrid,Le Roux, Christophe,Dubac, Jacques,Roques, Nicolas
, p. 129 - 134 (2002)
Bismuth(III) bis(trifluoromethanesulfonyl)amide (Bi(NTf2)3, 3) has been prepared from the reaction of protiodemetallation of tri-p-tolylbismuth by a stoichiometric amount of bis(trifluoromethanesulfonyl)amine (1). The intermediates BiPh3-n(NTf2)n (n=2 (4), 1 (5)) resulting from the reaction of 1 with triphenylbismuth have also been isolated. The amide 3 was able to catalyze the benzoylation and the benzenesulfonylation of toluene.
