scholarly journals Influence of Reaction Conditions on the Catalytic Oxidation of Cyclohexene with Molecular Oxygen Using a Series of Keggin-Type Polyoxometalate

2015 ◽  
Vol 31 (4) ◽  
pp. 2277-2284 ◽  
Author(s):  
Ramyah Radman ◽  
Ahmed Aouissi ◽  
Wafa Mekhamer
2021 ◽  
Vol 903 ◽  
pp. 143-148
Author(s):  
Svetlana Cornaja ◽  
Svetlana Zhizhkuna ◽  
Jevgenija Vladiko

Supported 3wt%Pd/α-Al₂O₃ catalyst was tested in selective oxidation of 1,2-propanediol by molecular oxygen. It was found that the catalyst is active in an alkaline water solution. Lactic acid was obtained as the main product of the reaction. Influence of different reaction conditions on 1,2-PDO conversion and oxidation process selectivity was studied. Partial kinetic orders of the reaction with respect to 1,2-propanediol, c0(NaOH), p(O2), n(1,2-PDO)/n(Pd)) were determined and an experimental kinetic model of the catalytic oxidation reaction was obtained. Activation energy of the process was calculated and was found to be about 53 ± 5 kJ/mol.


Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1281 ◽  
Author(s):  
Yongwei Ju ◽  
Zhongtian Du ◽  
Chuhong Xiao ◽  
Xingfei Li ◽  
Shuang Li

Selective oxidation of α-hydroxy esters is one of the most important methods to prepare high value-added α-keto esters. An efficient catalytic system consisting of Zn(NO3)2/VOC2O4 is reported for catalytic oxidation of α-hydroxy esters with molecular oxygen. Up to 99% conversion of methyl DL-mandelate or methyl lactate could be facilely obtained with high selectivity for its corresponding α-keto ester under mild reaction conditions. Zn(NO3)2 exhibited higher catalytic activity in combination with VOC2O4 compared with Fe(NO3)3 and different nitric oxidative gases were detected by situ attenuated total reflection infrared (ATR-IR) spectroscopy. UV-vis and ATR-IR results indicated that coordination complex formed in Zn(NO3)2 in CH3CN solution was quite different from Fe(NO3)3; it is proposed that the charge-transfer from Zn2+ to coordinated nitrate groups might account for the generation of different nitric oxidative gases. The XPS result indicate that nitric oxidative gas derived from the interaction of Zn(NO3)2 with VOC2O4 could be in favor of oxidizing VOC2O4 to generate active vanadium (V) species. It might account for different catalytic activity of Zn(NO3)2 or Fe(NO3)3 combined with VOC2O4. This work contributes to further development of efficient aerobic oxidation under mild reaction conditions.


Synlett ◽  
2018 ◽  
Vol 29 (14) ◽  
pp. 1914-1920 ◽  
Author(s):  
Meichao Li ◽  
Zhenlu Shen ◽  
Chaorong Xu ◽  
Shanli Yi ◽  
Xinquan Hu ◽  
...  

A novel aerobic catalytic oxidation system for the sulfenylation of indoles with a variety of sulfenylation agents through oxidative C–S bond coupling has been successfully developed. The reactions were performed with potassium iodide as the catalyst, sodium nitrite as the co-catalyst, and molecular oxygen as the terminal oxidant in the presence of acetic acid. Under the optimal reaction conditions, a number of indoles could be sulfenylated with Bunte salts, thiols, or disulfides to generate 3-sulfenylindoles in good yields. This protocol provided an efficient and environmentally benign strategy for the synthesis of 3-sulfenylindoles.


Author(s):  
Stefano Colonna ◽  
Nicoletta Gaggero ◽  
Fernando Montanari ◽  
Gianluca Pozzi ◽  
Silvio Quici

2020 ◽  
Vol 26 (1) ◽  
pp. 168-175
Author(s):  
Jinge Wang ◽  
Siyitemer Osman ◽  
Xinjiang Lu ◽  
Junyi Chen ◽  
Xu-Dong Xia

AbstractA convenient aerobic oxidative hydroxylation of 3-substituted oxindoles under mild reaction conditions is described herein. This process was accomplished by the activation of molecular oxygen in the air in the presence of a photocatalyst under the irradiation of visible light. The desired product was delivered in up to 89% yield without the addition of base or stoichiometric oxidant.


Author(s):  
Gui Chen ◽  
Kuiyi You ◽  
Xiangbo Gong ◽  
Fangfang Zhao ◽  
Zhenpan Chen ◽  
...  

An efficient method for highly selective preparation of the high value-added benzyl alcohol (BOL) and benzaldehyde (BAL) from liquid-phase catalytic oxidation of toluene with molecular oxygen over CeO2-MnOx composite oxides...


2017 ◽  
Vol 41 (2) ◽  
pp. 88-92
Author(s):  
Shenggui Liu ◽  
Rongkai Pan ◽  
Wenyi Su ◽  
Guobi Li ◽  
Chunlin Ni

2,6-Bis[1-(pyridin-2-yl)-1H-benzo[d]-imidazol-2-yl]pyridine (bpbp), which has been synthesised by intramolecular thermocyclisation of N2,N6-bis[2-(pyridin-2-ylamino)phenyl]pyridine-2,6-dicarboxamide, reacts with sodium pyridine-2,6-dicarboxylate (pydic) and RuCl3 to give [Ru(bpbp)(pydic)] which can catalyse the oxidation of (1H-benzo[d]imidazol-2-yl)methanol to 1H-benzo[d]imidazole-2-carbaldehyde by H2O2. The optimal reaction conditions were: molar ratios of catalyst to substrate to H2O2 set at 1: 1000: 3000; reaction temperature 50 °C; reaction time 5 h. The yield of (1H-benzo[d]imidazol-2-yl) methanol was 70%.


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