131-58-8Relevant articles and documents
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
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.
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.
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.
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.
Light/Palladium-Promoted Benzylic C?H Acylation Using a Benzoyl Group as the Photo-Directing Group
Masuda, Yusuke,Ishida, Naoki,Murakami, Masahiro
, p. 403 - 406 (2019)
2-Methylphenyl ketones undergo site-selective acylation at the benzylic position when treated with acid anhydride under UV irradiation in the presence of a palladium catalyst. The benzoyl carbonyl group serves as the photo-directing group so that the ortho benzylic C?H bond is activated site-selectively.
REVERSAL OF THE BENZOPHENONE REACTIVITY UPON η2 -COMPLEXATION TO BIS( η5 -CYCLOPENTADIENYL)ZIRCONIUM
Rosenfeldt, Frank,Erker, Gerhard
, p. 1637 - 1640 (1980)
Reversal of the carbonyl activity of benzophenone, serving as electron donor in single-electron transfer processes and acting as a proton acceptor through the 'carbonyl'carbon atom, is observed upon η2 -complexation to zirconocene.
Suzuki-Miyaura cross-coupling of esters by selective O-C(O) cleavage mediated by air- And moisture-stable [Pd(NHC)(μ-Cl)Cl]2precatalysts: Catalyst evaluation and mechanism
Cavallo, Luigi,Nolan, Steven P.,Poater, Albert,Szostak, Michal,Yang, Shiyi,Zhou, Tongliang
, p. 3189 - 3197 (2021/05/25)
The cross-coupling of aryl esters has emerged as a powerful platform for the functionalization of otherwise inert acyl C-O bonds in chemical synthesis and catalysis. Herein, we report a combined experimental and computational study on the acyl Suzuki-Miyaura cross-coupling of aryl esters mediated by well-defined, air- and moisture-stable Pd(ii)-NHC precatalysts [Pd(NHC)(μ-Cl)Cl]2. We present a comprehensive evaluation of [Pd(NHC)(μ-Cl)Cl]2 precatalysts and compare them with the present state-of-the-art [(Pd(NHC)allyl] precatalysts bearing allyl-type throw-away ligands. Most importantly, the study reveals [Pd(NHC)(μ-Cl)Cl]2 as the most reactive precatalysts discovered to date in this reactivity manifold. The unique synthetic utility of this unconventional O-C(O) cross-coupling is highlighted in the late-stage functionalization of pharmaceuticals and sequential chemoselective cross-coupling, providing access to valuable ketone products by a catalytic mechanism involving Pd insertion into the aryl ester bond. Furthermore, we present a comprehensive study of the catalytic cycle by DFT methods. Considering the clear advantages of [Pd(NHC)(μ-Cl)Cl]2 precatalysts on several levels, including facile one-pot synthesis, superior atom-economic profile to all other Pd(ii)-NHC catalysts, and versatile reactivity, these should be considered as the 'first-choice' catalysts for all routine applications in ester O-C(O) bond activation.
Self-Assembled 2,3-Dicyanopyrazino Phenanthrene Aggregates as a Visible-Light Photocatalyst
He, Min,Yu, Xiaoqiang,Wang, Yi,Li, Fei,Bao, Ming
, p. 5016 - 5025 (2021/04/12)
In this study, 2,3-dicyanopyrazino phenanthrene (DCPP), a commodity chemical that can be prepared at an industrial scale, was used as a photocatalyst in lieu of Ru or Ir complexes in C-X (X = C, N, and O) bond-forming reactions under visible-light irradiation. In these reactions, [DCPP]n aggregates were formed in situ through physical π-πstacking of DCPP monomers in organic solvents. These aggregates exhibited excellent photo- and electrochemical properties, including a visible light response (430 nm), long excited-state lifetime (19.3 μs), high excited-state reduction potential (Ered([DCPP]n*/[DCPP]n·-) = +2.10 V vs SCE), and good reduction stability. The applications of [DCPP]n aggregates as a versatile visible-light photocatalyst were demonstrated in decarboxylative C-C cross-coupling, amidation, and esterification reactions.