杂多酸催化环己烯氧化合成己二酸

催化氧化;过氧化氢杂多酸;杂多酸催化环己烯氧化合成己二酸     

钨酸催化氧化环己烯合成己二酸

以钨酸/有机酸性添加剂为催化体系, 在无有机溶剂、相转移剂的情况下, 催化30%过氧化氢氧化环己烯合成己二酸. 当钨酸∶有机酸性添加剂∶环己烯∶过氧化氢＝1∶1∶40∶176(摩尔比, 钨酸用量为2.5 mmol)时, 使用有机酸性添加剂考察钨酸的催化性能, 结果表明以钨酸/间苯二酚催化氧化环己烯的催化效果最优, 反应8 h时己二酸分离产率达90.9%、纯度为～100%; 而不使用有机酸性添加剂时, 己二酸分离产率只有72.1%, 产品纯度为96.2%. 当使用磺酸水杨酸、草酸、水杨酸为有机酸性添加剂时, 随反应时间的增加, 己二酸分离产率均升高, 但反应6 h以后, 己二酸分离产率随时间的变化不明显. 当磺酸水杨酸用量为2.5 mmol时, 己二酸分离产率和纯度均较高. 钨酸-磺酸水杨酸催化体系重复使用五次后, 己二酸分离产率仍可达到80.5%.     

环己烯催化氧化合成己二酸研究进展

苯部分催化加氢工艺的开发与日渐成熟,促进了以环己烯为原料取代环己酮、环己烷、环己醇等合成己二酸工艺路线的研究,并成为热点。本文综述了以环己烯为原料合成己二酸的催化剂研究进展,并概述了各类催化体系合成方法的优缺点,指出寻找更新颖的催化剂和更经济的氧源仍将是研究的重点。     

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。     

钨酸催化氧化环己烯合成己二酸

以钨酸为催化剂,过氧化氢为氧化剂,催化氧化环己烯(1)合成了己二酸（2）,其结构经¹H NMR和IR确证。采用正交实验法研究了过氧化氢浓度、钨酸用量和磷酸用量对2收率的影响。采用单因素法考察了酸性助剂,过氧化氢用量及其加料方式对收率的影响。结果表明：在最佳反应条件［n(H₂O₂)：n(1)：n(钨酸)=4.6 ：1.0：0.06, w(H₂O₂)=27.5%,回流反应1.7 h］下,2收率95.1%,纯度99.2%。     

清洁催化氧化环己烯合成己二酸反应中酸性配体的作用

 以30％H2O2为氧源，研究了Na2WO4·2H2O催化氧化环己烯制己二\r\n酸反应中的配体效应．在大多数情况下，配体的酸性越强，目标产物己\r\n二酸的产率越高．尽管一些酚类配体、L（＋）抗坏血酸和8－羟基喹啉\r\n的酸性较弱，但己二酸的产率仍然很高．这表明影响目标产物产率的因\r\n素除配体的酸效应以外，还存在配体的配位效应．邻苯二酚和对苯二酚\r\n等酚类配体的实验结果表明，反应可能是通过络合催化反应机理完成的\r\n．对酸性配体用量及对反应动力学考察结果表明，反应过程中环氧化物\r\n水解为1，2－环己二醇是整个反应的控制步骤，反应体系的酸性起到决\r\n定性的作用．     

清洁催化氧化合成己二酸

以新颖的过氧钨酸盐——有机酸配位络合物为催化剂,在无溶剂和无相转移剂的条件下,用30％的过氧化氢氧化环己烯合成己二酸,其收率可达93－95％。本文讨论了配位体种类及催化剂用量对反应的影响。     

钯催化环己烯氧化合成环己酮

考察了由不同金属酞菁（ＭＰｃ，Ｍ＝Ｆｅ，Ｃｏ，Ｃｕ）氯代金属卟啉（ＭＴＰＰＣ．，Ｍ＝Ｆｅ，Ｃｒ，Ｍｎ）和Ｐｄ（ＯＡｃ）２（醋酸钯）／ＨＱ（氢醌）组成的催化体系对环己烯氧化成环己酮的催化活性。表明，在乙腈酸性水溶液中，Ｐｄ（ＯＡｃ）２／ＨＱ／ＦｅＰｃ催化体系对环己烯氧化合成环己酮显示出较高的催化活性，在３０ｍｉｎ内环己酮收率可达８４％，选择性＞９８％，研究了各种因素对体系催化活性的影响。     

催化氧化合成己二酸的清洁方法*

己二酸是一种非常重要的有机合成中间体,由于传统生产工艺的局限性,其绿色合成方法备受研究者的关注。本文综述了近年来用H₂O₂、O₂或O₃作为清洁氧化剂,以环己烯、环己酮、环己醇或其混合物为原料,催化氧化合成己二酸清洁方法的研究进展,重点介绍了含钨化合物-双氧水体系的催化氧化法,也概述了几种新的己二酸合成方法,并从溶剂、产率、后处理等方面探讨了各种方法的优缺点。在这些方法中,负载催化剂-双氧水体系将是未来工业化的最佳选择之一。     

用十聚钨酸季铵盐催化过氧化氢氧化环己烯为己二酸

己二酸是重要的化学品.开发绿色、洁净的氧化方法合成己二酸,一直吸引着许多化学工作者的注意.1998年,Noyori等[1]报道了使用钨酸钠和甲基三辛基硫酸氢铵作为催化剂把环己烯氧化为己二酸的方法.1999年邓友全等[2,3]报道了在钨酸钠和草酸等形成原位过氧钨酸有机配合物催化剂存在下,使用30%过氧化氢由环己烯合成己二酸的方法.姜恒等[4,5]先后在甲基三辛基硫酸氢铵替代物的选择上和过氧钨酸有机配合物有机配体的作用方面进行了较为系统的工作.这些研究工作虽然都能直接获得高质量和高产率的己二酸,但是都存在着催化剂难于分离的问题.重复…     

含钨化合物催化合成己二酸研究进展

己二酸是工业上具有重要应用的二元羧酸,其合成方法的研究受到了广泛的关注.其传统的合成方法对环境造成了极大的破坏.利用含钨化合物作为催化剂催化合成己二酸是一种绿色环保的新方法,引起了人们的重视.作者介绍了近年来含钨化合物催化合成己二酸的研究进展,分析比较了不同催化剂体系的研究情况,展望了今后己二酸合成的发展前景.     

Oxodiperoxo tungsten complex-catalyzed synthesis of adipic acid with hydrogen peroxide

An amphiphilic oxodiperoxo complex of tungsten using 8-quinolinol (QOH) as ligand has been synthesized and characterized by elemental analyses, gravimetry, chemistry titration, TG/DSC, IR and UV-vis spectroscopy. Oxidation of cyclohexene, cyclohexanol, cyclohexanone, cyclohexene oxide and 1,2-cyclohexane-diol to adipic acid in one-step was conducted by this complex catalyst using 30 wt.% hydrogen peroxide in the absence of organic solvent and phase-transfer catalyst. The effect of the reaction conditions on the oxidation of cyclohexene was studied by varying the amount of the catalyst, reaction temperature, reaction time and the amount of hydrogen peroxide. The results showed that oxodiperoxo tungsten complex with QOH as ligand could achieve 89.8% yield of adipic acid at 90°C by refluxing for 20 h.     

Clean Synthesis of adipic acid by direct oxidation of cyclohexene in the absence of phase transfer agents

In the absence of phase-transfer agents, the ligand effects are studied for the clean synthesis of adipic acid by direct oxidation of cyclohexene catalyzed by Na₂WO₄·2H₂O with 30% hydrogen peroxide. In most cases, the isolated yield of the target product adipic acid is high if the ligand acidity is strong. Although the acidity of some phenolic ligands, L(+)ascorbic acid and 8-quinolinol is weak, the isolated yield of adipic acid is still high. It is demonstrated that the acid and coordination effect of the ligand play the same important role in the Na₂WO₄·2H₂O catalyzed oxidation of cyclohexene to adipic acid with 30% hydrogen peroxide. Kinetic investigations show that the hydrolysis of cyclohexene oxide to 1,2-cyclohexandiol is the critical step and the acidity of reaction system is important.     

Na_2WO_4催化H_2O_2氧化环己烯合成己二酸反应研究

以Na2WO4为催化剂,H2O2(30wt.%)为氧化剂,考察了环己烯合成己二酸过程中反应条件的影响。采用单因素实验确定最佳的反应条件:反应体系的物料比为Na2WO4·2H2O∶H3PO4∶H2O2∶C6H10=5∶20∶400∶100(mmol比),Na2WO4与H2O2加热回流温度为60℃,加热回流时间为30 min,反应温度为102℃,反应时间为2 h,此时己二酸的产率最高为63%。采用正交实验法确定影响己二酸产率的三个主要因素顺序为:反应温度Na2WO4与H2O2加热回流时间Na2WO4与H2O2加热回流温度。     

A new process for preparing dialdehyde by catalytic oxidation of cyclic olefins with aqueous hydrogen peroxide

A. novel peroxo-niobophosphate was synthesized for the first time and used as a catalyst in the oxidation reaction of cyclic olefins with aqueous hydrogen peroxide to prepare dialdehy-des. The catalyst was characterized by elemental analysis, thermographic analyses, IR, UV/vis, 31P NMR and XPS spectra as [ π-C5H5N(CH2 )13 CH3 ]2 [ Nb4O6 (O2 )2 (PO4 )2 ] ·6H2O (PTNP). It showed high selectivity to glutaraldehyde in the catalytic oxidation of cyclopentene with aqueous hydrogen peroxide in ethanol.     

Sulfonated carbon catalyzed oxidation of aldehydes to carboxylic acids by hydrogen peroxide

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.     

Micellar catalytic effects in the oxidation of methyl phenyl sulfide with hydrogen peroxide and the hydrogen peroxocarbonate anion

The kinetics and mechanism of the catalysis by ammonium hydrogen carbonate oxidation of methyl phenyl sulfide with hydrogen peroxide has been investigated. Using the classical pseudo-phase model of micellar catalysis, the basic parameters of the catalytic process have been determined: the binding constants of H₂O₂, the HCO ₄ ⁻ anion, and the substrate to the surface of the micelles, and also the second order rate constants for the oxidation of methyl phenyl sulfide in the micellar phase. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 5, pp. 281–287, September–October, 2006.     

Comparison between various Keggin and Wells–Dawson sandwich‐type polyoxometalates in catalytic oxidation of cyclooctene and cyclohexene with hydrogen peroxide

The catalytic performance of tetra‐n‐butylammonium salts of Keggin and Wells–Dawson sandwich‐type polyoxotungstates, [M₄(PW₉O₃₄)₂]^m? and [M₄(P₂W₁₅O₅₆)₂]^n? (M = Mn²⁺, Fe³⁺, Co²⁺, Ni²⁺, Zn²⁺), in the oxidation of cyclooctene and cyclohexene with 30% hydrogen peroxide under various conditions was investigated. In comparison, Wells–Dawson sandwich‐type polyoxometalates were found to be less active than Keggin ones. In both of them, those containing Zn and Fe gave higher conversions for different oxidation conditions. These catalysts showed very good reusability in the oxidation reaction. Copyright © 2014 John Wiley & Sons, Ltd.