固载离子液体刷/过氧磷钨酸盐催化剂催化H2O2选择性氧化硫醚

以二氧化硅为载体,合成了一种新型的双层离子液体刷固载过氧磷钨酸盐催化剂.采用元素分析、IR和SEM-EDAX等手段对催化剂进行了表征.室温下,考察了该催化剂催化30％(质量分数)H2O2溶液选择性氧化硫醚为亚砜或砜的催化性能.结果表明,该催化剂具有很高的催化活性和选择性.采用1.1倍H2O2时,反应选择性地生成亚砜,仅...     

Simple and Friendly Sulfones Synthesis Using Aqueous Hydrogen Peroxide with a Reusable Keggin Molybdenum Heteropolyacid,Immobilized on Aminopropyl-Functionalized Silica

Keggin molybdenum heteropolyacid (H₃PMo₁₂O₄₀), immobilized on aminopropyl-functionalized silica catalysts, were made using two immobilization methods: incipient wetness and equilibrium adsorption. The material prepared for the equilibrium adsorption technique was found to be a highly efficient, ecofriendly, and recyclable heterogeneous catalyst for the selective oxidation of sulfides to sulfones in excellent yields, under mild reaction condition using 35% w/v aqueous hydrogen peroxide as the oxidant.     

Water as an Efficient Solvent for Oxygenation Transformations with 34% Hydrogen Peroxide Catalyzed by some Heteropolyoxometalates

Summary. A highly efficient, selective, fast, and cheap protocol is developed for oxidation of aromatic amines and alcohols utilizing 34% hydrogen peroxide in water catalyzed by some W- and Mo-based heteropolyoxometalates. Findings showed that dodecatungstophosphoric acid, H₃PW₁₂O₄₀, was the most efficient catalyst in the examined oxidation reactions. This methodology may prove to be a valuable alternative for eco-friendly green oxidation. Inherent simplicity, easy work up, and using regenerable catalysts were other key aspects of this oxidation protocol.     

Selective Oxidation of Sulfides to Sulfoxides/Sulfones by 30% Hydrogen Peroxide

Abstract

A selective and efficient procedure for the oxidation of various sulfides with sodium tungstate dihydrate with 30% hydrogen peroxide in the presence of trioctylmethylammonium dihydrogen phosphate, respectively, to the corresponding sulfoxides and sulfones is reported. The oxidation reaction is carried out at –5 to 0 °C in the presence of hydroxypropyl-β-cyclodextrins for sulfoxides or at 50–60 °C for sulfones. The mild reaction conditions, easy workup, and good yields of the products are the major advantages of this method.     

钨酸钠与酸性离子液体催化醇的环境友好氧化反应

钨酸钠与酸性离子液体组成的催化体系可以催化双氧水进行醇的清洁氧化,反应在有机底物/水两相中进行.本体系在催化氧化仲醇为相应的酮时具有很好的活性;催化伯醇氧化时可以得到相应的醛、羧酸或两者的混合物.整个催化体系具有很好的重复利用性.     

Kinetic Studies on the Oxidation of Organic Sulfides with Percarbonate in Acetic Acid

Oxidation of organic sulfides by anhydrous H₂O₂using percarbonate in glacial acetic acid is a second order reaction and is independent of the acidity of the medium. The oxidation conforms to the isokinetic and Hammett relationships.     

Selective Oxidation of Toluene with Hydrogen Peroxide Catalyzed by V-Mo-based Catalyst

The selective catalytic oxidation of toluene with hydrogen peroxide over V-Mo-based catalysts under mild conditions was studied.The promotion effect of Mo on the catalysts was studied with V/Al2O3 and Mo/Al2O3 as reference samples.The catalysts were characterized by XRD,TPR,and XPS techniques.The results show that the addition of Mo to V/Al2O3 may change the distribution of V species on Al2O3 surface.Over V-Mo/Al2O3 catalyst,highly dispersed amorphous V species facilitates benzaldehyde formation,and crystalline V2O5 species increases the conversion of toluene but decreases the selectivity to benzaldehyde,while AlVMoO7 species favors both the conversion of toluene and the formation of cresols.The yield of benzaldehyde depends remarkably on the surface O/Al and Mo/V atomic ratios,and gets to a maximum value of 13.2% with a selectivity of 79.5% at an O/Al atomic ratio of 3.0 and Mo/V atomic ratio of 0.7.     

水溶性金属卟啉催化过氧化氢氧化对苯二酚的动力学研究

我们利用紫外-可见分光光度法研究了25℃时金属卟啉Fe（TPPS）Cl和Co（TPPS）催化过氧化氢氧化对苯二酚（HQ）的动力学（其中,TPPS为四（p-磺酸钠苯基）卟啉）,探讨了体系酸度、过氧化氢／催化剂摩尔比、中心金属离子对催化反应的影响,提出了金属卟啉催化氧化对苯二酚的反应历程,建立了反应的动力学模型．研究结果表...     

基于杂多酸的负载离子液相催化在醇氧化中的应用

采用溶胶-凝胶法制备的离子液体功能化的二氧化硅对于杂多酸是一种可行的载体,三种商用杂多酸成功的负载在离子液体功能化的二氧化硅上作为醇氧化的催化剂.利用FTIR、XRD、XPS对该种负载离子液相催化剂进行了表征.基于磷钨酸的负载离子液相催化剂活性最好,高产率(大部分＞93%)的得到了相应的羰基化合物.且该催化剂经过简单的...     

Sulfonated Condensed Polynuclear Aromatic (S-Copna) Resin Catalyzed Selective Oxidation of Sulfides to Sulfoxides or Sulfones Using Hydrogen Peroxide

Abstract

Sulfonated condensed polynuclear aromatic (S-COPNA) resin was found to be a highly efficient, environmentally friendly, recyclable heterogeneous catalyst for the oxidation of alkyl and aryl sulfides to the corresponding sulfoxides or sulfones, in good yields under mild reaction conditions using 30% hydrogen peroxide as an oxidant.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Synthesis of the S-COPNA resin catalyst. Spectroscopic data for compounds.     

Oxidation of Sulfides with Hydrogen Peroxide Catalyzed by Vitamin B2 Derivatives

5-Ethyl-3-methyl-2′,4′:3′,5′-di-O-methylenedioxyriboflavinium perchlorate (1, DMRFlEt⁺ClO₄ ^–), derived readily from commercially available vitamin B₂ (riboflavin), exhibits high catalytic activity for the oxidation of organic sulfides with hydrogen peroxide. The reaction provides an efficient and selective method for the oxidative transformation of organic sulfides to the corresponding sulfoxides under mild conditions.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource: Full experimental and spectral details.]     

Oxidation of Organic Compounds by Sulfonated Porous Carbon and Hydrogen Peroxide

 The oxidation of organic compounds by sulfonated porous carbon and H2O2 was studied at room temperature. Alkyl and aryl sulfides were oxidized to the corresponding sulfoxides or sulfones in excellent yields. Secondary alcohols were also converted to the corresponding esters/lactones and aldehydes to methyl esters in good yields. Moreover, aliphatic tertiary amines and substituted pyridines were oxidized to N-oxides.     

钼、钨过氧配合物催化过氧化氢氧化烯烃和醇类反应的研究进展

综述了在钼、钨过氧配合物催化下，用清洁氧化剂对过氧化氢氧化醇类和烯烃 的最新研究进展。     

有机碱介入的芳香羧酸氧钒催化过氧化氢氧化茴香脑

以N,N-二甲基甲酰胺(DMF)及杂环氮碱为添加剂,研究了有机碱对芳香羧酸氧钒催化过氧化氢氧化茴香脑制备茴香醛的调变作用.考察了催化剂性质、添加剂种类、DMF用量和反应时间等因素对茴香脑选择氧化的影响,发现DMF作为温和的Lewis碱与pH值调节剂,对茴香脑的转化及主产物茴香醛的选择性具有明显的调控作用.结果表明,以化...     

金属卟啉催化的过氧化氢选择氧化烃类反应机理研究

本文综合介绍了近年来采用过氧化氢为氧化剂,金属铁卟啉和锰卟啉模拟酶体系催化烯烃环氧化和烷烃氧化的反应机理。总结了采用不同手段促进过氧化氢的异裂,以有效形成金属卟啉活性中间体的反应过程。     

Water as an Efficient Solvent for Oxygenation Transformations with 34% Hydrogen Peroxide Catalyzed by some Heteropolyoxometalates

A highly efficient, selective, fast, and cheap protocol is developed for oxidation of aromatic amines and alcohols utilizing 34% hydrogen peroxide in water catalyzed by some W- and Mo-based heteropolyoxometalates. Findings showed that dodecatungstophosphoric acid, H₃PW₁₂O₄₀, was the most efficient catalyst in the examined oxidation reactions. This methodology may prove to be a valuable alternative for eco-friendly green oxidation. Inherent simplicity, easy work up, and using regenerable catalysts were other key aspects of this oxidation protocol.     

Kinetics of the Oxidation of Methyl Phenyl Sulfide by Hydrogen Peroxide in the Presence of Hydrocarbonate Anion

The oxidation of methyl phenyl sulfide in water and water-alcohol mixtures takes place both by a noncatalytic mechanism and with the participation of hydrogen peroxide as catalyst; in the presence of ammonium hydrocarbonate it takes place by a mechanism involving HCO ₄ ⁻ as a more active oxidant than hydrogen peroxide (>100 times). In water-alcohol media (ethylene glycol, isopropyl alcohol, tert-butanol) the rate decreases in the order H₂O > EG > IPA > TBA. The reactivity of organic sulfides varies in the following way: MeSPh ≈ EtSPh << Et₂S. The results were interpreted from the standpoint of a molecular mechanism of oxidation of the sulfide with H₂O₂ and HCO ₄ ⁻ through a polar transition state, containing the HOX molecule (X = H, OH, OR) as acid-base catalyst.__________Translated from Teoreticheskaya i Eksperimental’naya Khimiya, Vol. 41, No. 2, pp. 94–99, March–April, 2005.     

Selective Oxidation of Sulfides to Sulfoxides using H2O2 Catalyzed by p-Toluenesulfonic Acid (p-TsOH) Under Solvent-Free Conditions

Abstract

An efficient, chemoselective, and environmental friendly procedure for the oxidation of sulfides to sulfoxides is described. Various types of aromatic and aliphatic sulfides are selectively oxidized to sulfoxides in good to excellent yields using 30% H₂O₂ in the presence of catalytic amounts of a p-TsOH under solvent-free conditions at room temperature.     

Photothermal Oxidation of Cinnamyl Alcohol with Hydrogen Peroxide Catalyzed by Gold Nanoparticle/Antimony-Doped Tin Oxide Nanocrystals

Gold nanoparticles with different mean sizes were formed on antimony-doped tin oxide nanocrystals by the temperature-varied deposition-precipitation method (Au/ATO NCs). Au/ATO NCs possess strong absorption in the near-infrared region due to Drude excitation in addition to the localized surface plasmon resonance (LSPR) of AuNPs around 530 nm. Au/ATO NCs show thermally activated catalytic activity for the oxidation of cinnamyl alcohol to cinnamaldehyde by hydrogen peroxide. The catalytic activity increases with a decrease in the mean Au particle size (d_Au) at 5.3 nm≤d_Au≤8.2 nm. Light irradiation (λ_ex >660 nm, ∼0.5 sun) of Au/ATO NCs increases the rate of reaction by more than twice with ∼95 % selectivity. Kinetic analyses indicated that the striking enhancement of the reaction stems from the rise in the temperature near the catalyst surface of ∼30 K due to the photothermal effect of the ATO NCs.     

磷钨酸催化过氧化氢氧化环己烯合成己二酸

报道了以苄基三乙基氯化铵为相转移催化剂，用磷钨酸催化地氢氧化环己烯合 成己二酸，在优化反应条件下：即反应物摩尔比为环己烯：H2O2：苄基三乙基氯化 铵：磷钨酸＝1：4.5:0.036:0.0015时，在60－65℃反应6h，再将温度升至80℃反 应5h，收率可达87％，探讨了不同反应条件对产率的影响。该方法避免了目前所常 采用的对环境有污染的硝酸氧化方法所产生的氮氧化物及废酸。