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A palladium‐TPPTS catalyst heterogenized on KF/alumina has been shown to be effective and recyclable for the selective formation of monooctadienylxylopyranosides via the telomerization of butadiene with D ‐xylose. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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卡尔曼滤波法用于ICP-AES分析时,在白色噪音情况下能给出准确的分析结果,当试样的某些组分未知时,测量噪音将不是白色的,分析结果将不准确。本文提出了一种加权增量卡尔曼滤波法来解决这个问题。 相似文献
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Organic sulfonyl fluorides are of interest owing to their insecticidal, germicidal and enzyme inhibitory properties. In the current work, synthesis of p-toluenesufonyl fluoride was accomplished by reacting p-toluenesulfonyl chloride with solid potassium fluoride using PEG-400 as a catalyst under solid-liquid phase transfer catalysis (S-L PTC) at 30 °C. p-Toluenesulfonyl fluoride is used as peroxygen bleach activator. It also finds use in the treatment of Alzheimer's disease. The mechanism is based on homogeneous solubilization of solid. PEG forms a complex with metal cation which associates with the nucleophile and it participates in SN2 type reactions. The reaction is intrinsically kinetically controlled. A complete theoretical analysis is done to determine both the rate constant and equilibrium constant from the same set of data. The activation energy and Gibbs free energy are also calculated. 相似文献
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Abdolkarim Zare Alireza Hasaninejad Mohammad Hassan Beyzavi Ahmad Reza Moosavi-Zare Ali Khalafi-Nezhad Mehrnoosh Roshankar 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1702-1712
KF/Al 2 O 3 efficiently catalyzes the microwave-assisted Michael addition of sulfonamides to α,β-unsaturated esters under solvent-free conditions to afford N-alkyl derivatives of sulfonamides as biologically interesting compounds in high yields and in short reaction times. In this reaction, N,N-dialkylsulfonamides are also produced, but in very low yields. 相似文献
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Trichloroisocyanuric acid–KF afforded dialkylfluorophosphates from dialkylphosphites at room temperature through a facile electrophilic–nucleophilic metathesis. 相似文献
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Rahman Hosseinzadeh Mahmood Tajbakhsh Maryam Mohadjerani Parizad Rezaei Mohammad Alikarami 《合成通讯》2013,43(17):3023-3031
An efficient synthesis of diaryl ethers by the copper-catalyzed arylation of phenols with a variety of aryl iodide susing KF/Al2O3 as a suitable base and CuI and 1,3 diphenyl-1,3 propandione as the catalyst is described. 相似文献
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《合成通讯》2013,43(18):3265-3271
Abstract A series of new 2‐amino‐3‐cyano‐4‐aryl‐1,4,5,6‐tetrahydrobenzo[h]chromenes derivatives were synthesized by the reaction of malononitrile with 2‐arylmethylidene‐3, 4‐dihydro‐1(2H)‐naphthalenone in N,N‐dimethylformamide (DMF) at 80°C catalyzed by KF‐Al2O3. The structure of the product was confirmed by x‐ray analysis. 相似文献
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KF‐Melamine formaldehyde resin (KF‐MFR) was demonstrated to be a highly efficient heterogenious catalyst for cross‐aldol condensation under microwave irradiation. In this synthesis, various aldehydes and ketones were condensed together in the presence of supported KF on melamine‐formaldehyde resin to afford different chalcone derivatives in good to excellent yields. KF‐MFR proved to have unique termal and chemical resistance and can be reused for many consecutive runs without remarkable loss in catalytic activity. 相似文献
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超声作用下KF/CaO催化酯交换反应制备生物柴油 总被引:3,自引:0,他引:3
等体积浸渍法制备了KF/CaO固体碱催化剂,用于催化大豆油与甲醇酯交换反应制备生物柴油,在反应体系中引入超声作为辅助条件。研究表明,KF/CaO催化活性高。在超声的辅助作用下,酯交换反应速率加快,生物柴油的收率提高。实验考察了反应条件对产品中脂肪酸甲酯含量的影响。醇油摩尔比为12∶1,反应温度65℃,催化剂与大豆油的质量比为3%,反应1 h,超声频率20 kHz,超声声强1.01 W/cm2,在此反应条件下,产品中脂肪酸甲酯的质量分数达到99.6%。 相似文献