共查询到20条相似文献,搜索用时 0 毫秒
1.
Qing Hua Zhang Shou Feng Wang Zi Qiang Lei 《中国化学快报》2007,18(1):4-6
Sn-aniline complex was prepared by a simple procedure.Cyclic and acyclic ketones were oxidized into lactones or esters with very high selectivity and yield with 30% hydrogen peroxide in the presence of Sn-aniline complex. 相似文献
2.
A novel diselenide was synthesized in good yield via only four steps from phenol, and was employed as the catalyst for the Baeyer-Villiger oxidation with 30% H2O2 to obtain lactones in good yields. 相似文献
3.
Baeyer-Villiger oxidation of ketones with hydrogen peroxide catalyzed by Sn-palygorskite 总被引:1,自引:0,他引:1
Palygorskite-supported Sn complexes were prepared by a simple procedure. Cyclic ketones and acyclic ketones were oxidized by hydrogen peroxide in a reaction catalyzed by palygorskite-supported Sn complexes, affording corresponding lactones or esters with selectivity for the product of 90-100%. The catalysts can be recycled for several times without significant decline in catalytic activity. 相似文献
4.
Ziqiang Lei Qinghua Zhang Rongmin Wang Guofu Ma Chengguo Jia 《Journal of organometallic chemistry》2006,691(26):5767-5773
An environmentally benign and selective Baeyer-Villiger oxidation system is introduced. Palygorskite-supported Sn complexes were prepared by a simple procedure. Cyclic ketones and acyclic ketones were oxidized by hydrogen peroxide in a reaction catalyzed by palygorskite-supported Sn complexes, affording corresponding lactones or esters with selectivity for the product of 90-99%. The influence of the solvents, reaction temperature, the amount of catalyst used and the reaction time on the catalytic activity and product selectivity were investigated in detail. The catalyst is cheap, easy to be prepared in large scale and can be recycled. 相似文献
5.
Georgiy B. Shul’pin Aleksandr R. Kudinov Elena A. Petrovskaya 《Journal of organometallic chemistry》2006,691(5):837-845
A carbonyl osmium(0) complex with π-coordinated olefin, (2,3-η-1,4-diphenylbut-2-en-1,4-dione)undecacarbonyl triangulotriosmium (1), efficiently catalyzes oxygenation of alkanes (cyclohexane, cyclooctane, n-heptane, isooctane, etc.) with hydrogen peroxide, as well as with tert-butyl hydroperoxide and meta-chloroperoxybenzoic acid in acetonitrile solution. Alkanes are oxidized to corresponding alcohols, ketones (aldehydes) and alkyl hydroperoxides. Thus, heating cyclooctane with the 1-H2O2 combination at 70 °C gave products with turnover number as high as 2400 after 6 h. The maximum obtained yield of all products was equal to 20% based on cyclohexane and 30% based on H2O2. The oxidation of linear and branched alkanes exhibits very low regio- and bond-selectivity parameters and this testifies that the reaction proceeds via attack of hydroxyl radicals on C-H bonds of the alkane. The oxygenation products were not formed when the reaction was carried out under argon atmosphere and it can be thus concluded that the oxygenation occurs via the reaction between alkyl radicals and atmospheric oxygen. In summary, the Os(0) complex is much more powerful generator of hydroxyl radicals than any soluble derivative of iron (which is an analogue of osmium in the Periodic System). 相似文献
6.
Titanosilicalite TS-1 catalyses oxidation of light (methane, ethane, propane and n-butane) and normal higher (hexane, heptane, octane and nonane) alkanes to give the corresponding isomeric alcohols and ketones. The oxidation of higher alkanes proceeds in many cases with a unique regioselectivity. Thus, in the reaction with n-heptane the CH2 groups in position 3 exhibited a reactivity 2.5 times higher than those of the other methylene groups. This selectivity can be enhanced if hexan-3-ol is added to the reaction mixture, the 3-CH2/2-CH2 ratio becoming 10. It is assumed that the unusual selectivity in the oxidation of n-heptane (and other higher alkanes) is due to steric hindrance in the catalyst cavity. As a result, the catalytically active species situated on the catalyst walls can only easily react with certain methylenes of the alkane, which is adsorbed in the cavity taking U-shape (hairpin) conformations. 相似文献
7.
Gennady I. Panov Konstantin A. Dubkov Evgeny V. Starokon Valentin N. Parmon 《Reaction Kinetics and Catalysis Letters》2002,76(2):401-406
A very efficient way of alkenes oxidation to carbonyl compounds is discovered. It is based on remarkable ability of nitrous oxide to interact directly with the double C=C bonds of liquid alkene and to transfer its oxygen, without catalyst aid, to unsaturated carbon atom with nearly 100% selectivity. This oxidation method can be applied to a wide range of organic compounds including aliphatic, cyclic, heterocyclic alkenes and their numerous derivatives. 相似文献
8.
Francesco P. Ballistreri Gaetano A. Tomaselli Rosa M. Toscano 《Tetrahedron letters》2008,49(20):3291-3293
Aromatic and aliphatic thiols are oxidized in acetonitrile at 20 °C by hydrogen peroxide in the presence of methyltrioxorhenium as the catalyst to yield the corresponding sulfonic acids in high isolated yields (85-94%). 相似文献
9.
The biomimetic oxidation of metribuzin, a pre- and post-emergence herbicide with hydrogen peroxide catalyzed by 5,10,15,20-tetraarylporphyrinatoiron(III) chlorides [TAPFe(III)Cl], has been studied yielding 6-t-butyl-3-methylthio-1,2,4-triazine-5(4H)-one, 4-amino-6-t-butyl-3,5(2H,4H)-dione and 6-t-butyl-1,2,4-triazin-3,5(2H,4H)-dione under various reaction conditions. 相似文献
10.
11.
Lipeng Zhou Beibei Dong Si Tang Hong Ma Chen Chen Xiaomei Yang Jie Xu 《Journal of Energy Chemistry》2013,22(4):659-664
Sulfonated carbon as a strong and stable solid acid catalyst exhibited excellent catalytic performance in various acid-catalyzed reactions. Here, sulfonated carbon, as catalyst for oxidation reaction, was prepared via the carbonization of starch followed by sulfonation with concentrated sulfuric acid. N2 physisorption, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray fluorescence and acid-base titration were used to characterize the obtained materials. The catalytic activity of sulfonated carbon was studied in the oxidation of aldehydes to carboxylic acids using 30 wt% H2O2 as oxidant. This oxidation protocol works well for various aldehydes including aromatic and aliphatic aldehydes. The sulfonated carbon can be recycled for three times without obvious loss of activity. 相似文献
12.
Yasuhiro Aoki 《Tetrahedron》2005,61(22):5219-5222
Synthesis of phenol and cyclohexanone in one pot was examined by means of the NHPI-catalyzed aerobic oxidation of cyclohexylbenzene. The aerobic oxidation of cyclohexylbenzene catalyzed by NHPI followed by treatment with sulfuric acid afforded phenol and cyclohexanone in good selectivities. Thus, the reaction of cyclohexylbenzene under atmospheric dioxygen (1 atm) by NHPI at 100 °C for 3 h followed by treatment with 0.3 M sulfuric acid at room temperature for 2 h resulted in phenol and cyclohexanone in 96 and 91% selectivity, respectively, at 25% conversion. This method was successfully extended to the one-pot synthesis of 4-hydroxyacetophenone and cyclohexanone. 相似文献
13.
A convenient and efficient method for preparing 3,3,3-trifluoropropanoic acid (1) is reported. The starting material is 1-chloro-3,3,3-trifluoropropene (2) that can be easily transformed into 3,3,3-trifluoropropanal dimethyl acetal (4) on treatment with methanol and KOH followed by acid-catalyzed addition of methanol. Direct transformation of 4 into 1 was efficiently achieved with 30% aqueous hydrogen peroxide (4.0 equiv.) in the presence of FeCl3 (0.025 equiv.) and hydrochloric acid (0.5 equiv.). 相似文献
14.
N-Boc derivatives of Met, Cys, and Trp, the properties of which resemble those of the respective amino acid residues present in proteins, are efficiently oxidized by methyltrioxorhenium and H2O2. A high regioselectivity for the oxidation of these residues when embedded into peptides was also found. 相似文献
15.
Cláudia M.B. NevesMário M.Q. Simões Isabel C.M.S. SantosFernando M.J. Domingues M. Graça P.M.S. Neves Filipe A. Almeida PazArtur M.S. Silva José A.S. Cavaleiro 《Tetrahedron letters》2011,52(22):2898-2902
The biomimetic oxidation of caffeine with hydrogen peroxide using metalloporphyrins as catalysts, which are known to be good biomimetic models of cytochrome P450 enzymes, is investigated. The two manganese porphyrins tested, chloro[5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrinato]manganese(III), [Mn(TDCPP)Cl], and chloro [5,10,15,20-tetrakis(pentafluorophenyl)porphyrinato]manganese(III), [Mn(TPFPP)Cl], afford high conversions of caffeine for all substrate/catalyst molar ratios. Selectivity was found to be dependent on the catalyst employed, and a new spiro racemic compound is described and fully characterized in the solid state from X-ray diffraction studies. 相似文献
16.
17.
环己酮绿色氧化合成己二酸质谱分析 总被引:3,自引:0,他引:3
己二酸是合成尼龙-66的主要原料,同时在低温润滑油、合成纤维、油漆、聚亚胺酯树脂及食品添加剂的制备等方面也有重要用途,目前己二酸的世界年产量估计已达220万吨。工业上已二酸的生产是以环己烷经两步氧化合成,第一步为环己烷在金属离子催化下用氧气氧化为环己醇、环己酮,第二步用浓HNO3氧化环己醇、环己酮制得己二酸。在第二步氧化时由于用了浓HNO3故产生大量的CO、NOx、N2O等有毒气体,其中N2O是比CO2还强310倍的温室气体。在当今普遍提倡绿色化学的时代,如何减少化工生产对环境的污染是当前化学工作者首要解决的任务。过氧化氢是一种理想的清洁氧化剂,其反应的唯一预期副产物是水,反应后处理容易,同时过氧化氢的价格相对低廉,氧化成本低。为此,许多化学工作者对环己酮绿色氧化制剂己二酸已有研究。但环己酮氧化为己二酸的反应产物的研究未见报道,本文报道环己酮氧化为己二酸的12种产物。 相似文献
18.
The utilization of organogallium and organoindium compounds as alkylation reagents to aldehydes was realized with titanium tetrachloride as the strong Lewis acid catalyst. Furthermore, the catalytic asymmetric addition of organogallium to aldehydes was investigated with chiral titanium complexes, which were formed from titanium tetrachloride and salan ligands, with mediocre to good chemical yields and enantioselectivities. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
19.
Primary and secondary benzylic alcohols were oxidized to the corresponding carbonyl compounds in good to high yields by environmentally friendly and green oxidant, H2O2 catalyzed by montmorillonite K-10 supported cobalt(Ⅱ) chloride. 相似文献
20.
Gholam Reza Najafi 《中国化学快报》2010,21(10):1162-1164
<正>Primary and secondary benzylic alcohols were oxidized to the corresponding carbonyl compounds in good to high yields by environmentally friendly and green oxidant,H_2O_2 catalyzed by Montmorillonite-K10 supported manganese(Ⅱ) chloride. 相似文献