- Mechanism of Oxidation of Methylbenzenes by Palladium(II) in Trifluoroacetic Acid. One-electron Transfer and Electrophilic Substitution
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The oxidation of methylbenzenes by Pd(II) in CF3CO2H to give diarylmethanes has been shown to occur via a one-electron transfer mechanism.
- Kozhevnikov, Ivan V.,Kim, Vladimir I.,Talzi, Eugeni P.,Sidelnikov, Vladimir N.
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Read Online
- Cross-coupling of p-xylene to 2,2′,5,5′-tetramethyl 1,1′-biphenyl on supported vanadia catalysts
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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.
- Mitran, Gheorghi?a,Pavel, Octavian Dumitru,Florea, Mihaela,Parvulescu, Vasile I.
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- Direct hydroxylation of p-xylene to 2,5-xylenol with hydroxylamine in ionic liquids/molybdenum catalytic system
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Direct hydroxylation of p-xylene to 2,5-xylenol with hydroxylamine was carried out in an ionic liquids/molybdenum catalytic system. High 2,5-xylenol selectivity (80-98 %) can be achieved with good p-xylene conversion (5.9-9.9 %) in this catalytic system. The recycling experiments suggested the ionic liquids/molybdenum catalytic system was stable enough to be recycled for the hydroxylation reaction.
- Zhang,Gao,Jin,Xue,Zhao,Wang,Wang
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p. 7527 - 7531
(2015/02/02)
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- Pd-catalyzed decarboxylative cross-coupling of perfluorobenzoic acids with simple arenes
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Using a Pd/Ag bimetallic system, arylations of simple arenes with perfluorobenzoic acids have been achieved by decarboxylative C-H bond functionalization, providing the desired cross-coupling products in moderate to good yields. These straightforward protocols provide new and efficient methods for the synthesis of fluorobiphenyl scaffolds under simple and mild conditions.
- Luo, Hai-Qing,Dong, Wen,Loh, Teck-Peng
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supporting information
p. 2833 - 2836
(2013/06/05)
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- Gold(III)-catalyzed direct acetoxylation of arenes with iodobenzene diacetate
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AuCl3-catalyzed direct acetoxylation of electron-rich aromatic compounds has been achieved with iodobenzene diacetate as the acetoxylation reagent.
- Qiu, Di,Zheng, Zhitong,Mo, Fanyang,Xiao, Qing,Tian, Yu,Zhang, Yan,Wang, Jianbo
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supporting information; experimental part
p. 4988 - 4991
(2011/11/13)
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- Homocoupling of aryl iodides and bromides promoted by sulfur-containing palladacycles
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Sulfur-containing palladacycles, in particular those derived from the orthometalation of benzylthioethers, effectively promote the homocoupling of aryl iodides and bromides, under relatively mild reaction conditions to furnish symmetrical biphenyls in good yields.
- Silveira, Priscila B.,Lando, Vanusa R.,Dupont, Jairton,Monteiro, Adriano L.
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p. 2327 - 2329
(2007/10/03)
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- SYNTHESIS OF METHYL-SUBSTITUTED INDENOQUINOLINES, INDENOQUINOXALINES, AND THEIR KETO DERIVATIVES AND INVESTIGATION OF THEIR STRUCTURES
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A series of difficultly obtainable and previously unknown methyl homologs of 11H-indenoquinoline, 11H-indenoquinoxaline, and the corresponding 11-keto derivatives were synthesized by new convenient methods, and their structures were investigated.By PMR with lanthanide shift reagents Eu(dpm)3, Pr(dpm)3 and Yb(dpm)3 it was established that the indenoquinolines and ketoindenoquinoxalines do not coordinate with any of the indicated reagents, while the 11-keto derivatives of the indenoquinolines, like those of the indenoquinoxalines, only enter coordination with Yb(dpm)3 at the oxygen atom in the case of the ketoindenoqui nolines and at the N10 nitrogen atom in the case of the indenoquinoxalines.The results from quantum-chemical calculations on the keto derivatives of the indenoquinoline and indenoquinoxaline series are given, and the reasons for the various directions of coordination of Yb(dpm)3 with this type of compound are discussed.
- Prostakov, N. S.,Pleshakov, V. G.,Abedin, Md. Zainul,Kordova, I. R.,Zakharov, V. F.,Zvolinskii, V. P.
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p. 556 - 566
(2007/10/02)
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