104-87-0Relevant articles and documents
Au-Carbon Electronic Interaction Mediated Selective Oxidation of Styrene
Liu, Ben,Wang, Pu,Lopes, Aaron,Jin, Lei,Zhong, Wei,Pei, Yong,Suib, Steven L.,He, Jie
, p. 3483 - 3488 (2017)
The rational design of the Au-support electronic interaction is crucial for Au nanocatalysis. We herein report our observation of electronic perturbation at the Au-carbon interface and its application in controlling the reaction selectivity in styrene oxidation. Ultrasmall Au nanocatalysts were grown in situ on a nitrided carbon support where the nitrogen-doped carbon supports enriched the surface charge density and generated electron-rich Au surface sites. The Au-carbon interaction altered the binding behavior of C=C bonds to catalytic centers, leading to a solvent-polarity-dependent selectivity in C=C oxidation reactions. A high selectivity of 90% to benzaldehyde was achieved in an apolar solvent, and a selectivity of 95% to styrene epoxide was attained in a polar solvent. The Au-carbon electronic perturbation, originating from surface functional groups on the carbon support, may provide an alternative avenue to tune the selectivity and activity of more complex reactions in heterogeneous catalysis.
Orthoamides, LXIII [1]. Tris(dichloromethyl)amine, a new formylating reagent for aromatic compounds of wide scope
Kantlehner, Willi,Wezstein, Markus,Kre?, Ralf,Zschach, Franziska,Vetter, Jens,Ziegler, Georg,Mezger, Jochen,Stoyanov, Edmont V.,Goeppert, Alain,Sommer, Jean
, p. 448 - 463 (2006)
The reagent system formed from tris(dichloromethyl)amine (5) and aluminium chloride allows the formylation of aromatic compounds. The scope of the method is comparable with that of the Olah formylation and the Gro?-Rieche procedure, since benzene and even chlorobenzene can be formylated. One formyl group is transferred from 5 to the aromatic nucleus. In order to find optimal reaction conditions, the molar amounts of aromatic compounds, 5 and aluminum chloride were varied as well as reaction temperatures and solvents. The activation of 5 with other Lewis acids is also described.
Clay-anchored non-heme iron-salen complex catalyzed cleavage of C{double bond, long}C bond in aqueous medium
Dhakshinamoorthy, Amarajothi,Pitchumani, Kasi
, p. 9911 - 9918 (2006)
Clay-anchored iron[N,N′-ethylenebis(salicylideneaminato)] complex, synthesized by direct exchange, oxidizes various olefins and chalcones in aqueous acetonitrile using hydrogen peroxide as terminal oxidant. Aldehyde and its derivatives are obtained as oxidation products by the cleavage of C{double bond, long}C double bond. In comparison with the catalysis by iron-salen complex in solution, the clay catalyzed pathway not only increases the rate of reaction significantly, but also provides selective oxidation toward the aldehyde. Some chalcones also give very good yield in water, compared to the solution and clay catalyzed pathways.
Solvent-free and selective oxidation of hydroxy groups to their corresponding carbonyl functions with ferric nitrate activated by heteropoly acids
Firouzabadi, Habib,Iranpoor, Nasser,Amani, Kamal
, p. 408 - 412 (2003)
Keggin-type heteropoly acids revealed high catalytic activity for swift and selective oxidation of various hydroxy functionalities to the corresponding carbonyl groups using ferric nitrate as an oxidant under mild and solvent-free conditions. We have found that the catalytic activities of the heteropoly acids were much higher than mineral or solid acids such as sulfuric acid, p-toluenesulfonic acid, triflic acid, acidic Amberlyst-15, Montmorillonite-K10 clay, and HY-zeolite.
Convenient one-pot synthesis of aldehydes from carboxylic acid chlorides with sodium diethyldihydroaluminate
Yoon,Choi,Gyoung,Jun
, p. 1775 - 1781 (1993)
Carboxylic acid chlorides and acids were converted into the corresponding aldehydes conveniently in one-pot process with sodium diethyldihydroaluminate (SDDA) in moderate to good yields.
Functional hexanuclear Y(III) cluster-based MOFs supported Pd(II) single site catalysts for aerobic selective oxidation of styrene
Han, Zheng-Bo,Wei, Na,Xing, Zhiqiang,Zhang, Yue
, (2020)
Oxidation of styrene is one of the significant reactions in organic synthesis. In this work, a serious of PdCl2 moiety-decorated Y6-MOFs adopting post-synthetic strategy were fabricated as applicable single-site catalysts for oxidation of styrene. Specifically, the functional organic linker, H2bpydc (2,2′-bipyridine-5,5′-dicarboxylic acid), was first incorporated quantitatively into Y6 clusters-based MOF, [(CH3)2NH2]2[Y6(μ3-OH)8(bpdc)6] (bpdc = 4,4′-biphenyl dicarboxylic acid) via post-synthetic ligand exchange. Then post-synthetic Pd(II) metalation was performed to enhance the density of isolated single sites. The obtained Pd(II)-Y-bpydcx/bpdc1-x can be used as highly efficient heterogeneous single-site catalysts to promote selective oxidative cleavage of styrene to benzaldehyde using O2 as a oxidant under solvent-free and mild reaction conditions (1 atm and 80 °C). Importantly, when using Pd(II)-Y-bpydc0.8/bpdc0.2 (0.024 mmol Pd) as catalyst, the high conversion of styrene and the selectivity for benzaldehyde can reach 88.7 % and 82.2 %, respectively.
Hexadecylphosphate-functionalized iron oxide nanoparticles: Mild oxidation of benzyl C-H bonds exclusive to carbonyls by molecular oxygen
Li, Lei,Lv, Jiangang,Shen, Yi,Guo, Xuefeng,Peng, Luming,Xie, Zaiku,Ding, Weiping
, p. 2746 - 2752 (2014)
We report here a specially designed catalytic system consisting of hexadecylphosphate-functionalized iron oxide nanoparticles in oil/water biphasic emulsion. The iron oxide nanoparticles act as catalytic centers and the surface-bonded hexadecylphosphates as peripheral units which tune the activity of iron oxide and the access of reactants to the catalytic centers. The catalytic system is highly effective to oxidize the benzyl C-H bonds in a series of compounds to carbonyls exclusively by molecular oxygen under mild conditions. The catalytic process, green and low cost, offers a novel concept to design highly effective catalysts with nanoparticles as active centers and surface-bonded organic phosphates as accelerants for oxidation reactions.
Cross-coupling of p-xylene to 2,2′,5,5′-tetramethyl 1,1′-biphenyl on supported vanadia catalysts
Mitran, Gheorghi?a,Pavel, Octavian Dumitru,Florea, Mihaela,Parvulescu, Vasile I.
, p. 71 - 82 (2016)
Aluminas with different textural characteristics were synthesized by carbonate, citrate and urea sol-gel methods. All supports were impregnated with an aqueous solution of ammonium metavanadate in order to obtain the same loading of vanadia (7% wt V2O5), and then characterized by XRD, N2 physisorption, Raman spectroscopy and NH3-TPD. In this way it was possible to tune the characteristics of the supported vanadia as it has also been demonstrated from the catalytic behavior of these materials in the cross-coupling of p-xylene to 2,2′,5,5′-tetramethyl 1,1′ biphenyl (biaryl) in the presence of O2. Alumina prepared via the carbonate method and calcined at 500°C proved to be the most suitable support affording, for a level of conversion of 8%, selectivities to biaryl of 96%. It corresponded to an enough high dispersion of vanadium to allow the cleavage of the C-H bonds. Recycling experiments confirmed the stability of these catalysts.
FeCl3-catalyzed oxidative decarboxylation of aryl/heteroaryl acetic acids: Preparation of selected API impurities
Gangadurai, Chinnakuzhanthai,Illa, Giri Teja,Reddy, D. Srinivasa
, p. 8459 - 8466 (2020)
There is an ever-increasing demand for impurity compounds for use in impurity profiling as regulatory agencies seek information during registration. Herein, we report the FeCl3-catalyzed oxidative decarboxylation of aryl- and heteroaryl acetic acids to the corresponding carbonyl compounds. A variety of useful aldehydes and ketones were prepared in a simple one-pot transformation by employing an environmentally benign, low-cost, and readily available iron salt. The utility of this method has been demonstrated by preparing five valuable API impurities including a multi-gram-scale synthesis of ketorolac impurity B for the first time. This journal is
Deprotection of 1,3-Dithianes by 2,2-Dichlloro-5,6-dicyano-p-benzoquinone (DDQ)
Tanemura, Kiyoshi,Dohya, Hiroshi,Imamura, Masanori,Suzuki, Tsuneo,Horaguchi, Takaaki
, p. 965 - 968 (1994)
A variety of 1,3-dithianes were converted to the corresponding carbonyl compounds in good yields by treatment with 1.5 equiv. of 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) in MeCN-H2O (9:1).
