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考察了纤维素氧磷-钯配合物对有机锡试剂与有机卤化物交叉偶联反应的催化作用。 结果表明,该负载催化剂对偶联反应具有较高的催化活性和化学选择性,分离容易,可重复使用,XPS分析说明催化剂中起催化作用的是金属态钯。 相似文献
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用SiO2担载壳聚糖(CS),再与PdCl2配位,制得催化剂SiO2-CS-PdCl2,详细考察了催化剂对有机锡试剂和α-卤代酸酯交叉偶联反应的催化作用及使用寿命。结果表明该天然高分子负载型钯催化剂对偶联反应具有较高的催化活性和化学选择性,分离容易,可以重复使用,酯基在反应中不被破坏。催化剂循环使用6次,偶联反应产率仍在40%以上。采用XPS分析方法对催化剂进行了表征,证明催化活性中心是金属态钯,并对反应机理进行了研究和探讨。 相似文献
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制备了有机锡试剂Bu3SnPh,Bu3SnCH2Ph及催化剂Pd(Ⅱ)/γ-Al2O3催化剂对有机锡试剂与芳卤化合物的偶联反应有较高的活性。该反应条件温和,催化剂可重复使用,产率较高。 相似文献
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制备了有机锡试剂Bu3SnPh、Bu3SnCH2Ph及催化剂Pd(Ⅱ)/γAl2O3,催化剂对有机锡试剂与芳卤化合物的偶联反应有较高的活性。该反应条件温和,催化剂可重复使用,产率较高 相似文献
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In this paper we report a brief review of the palladium–catalyzed olefination and amination of aryl chlorides. Special emphasis
is given on the efficiency of known catalysts. Best turnover numbers (TON up to 40,000) known to date for Heck reactions are
displayed by palladacycle catalysts, e.g., 1 in the presence of salts as co–catalysts. Model studies show that the catalyst
productivity is strongly influenced by the nature of the added salt. In addition, the ability of mixtures of Pd(OAc)2 and phosphines to catalyze the reaction of styrene with 1–chloro–4–trifluoromethylbenzene was studied dependent on the Pd:P
ratio. It was found that apart from the palladacycle 1 a number of established phosphines permit efficient C–Cl activation.
Amination of aryl chlorides is also possible in the presence of palladacycles as catalyst precursors. Crucial for the success
of the C–N bond forming reaction is the use of potassium tert–butoxide as base and reaction temperatures > 120°C. Turnover
numbers up to 900 and yields up to 80% have been obtained for the amination of 1–chloro–4–trifluoromethylbenzene.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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钯催化芳基硼酸与芳卤偶联反应的工业应用新进展 总被引:1,自引:0,他引:1
钯催化芳基硼酸与芳卤偶联反应(即Suzuki反应)是用于碳碳键形成的重要方法之一,在有机合成中应用十分广泛。本文着重综述了钯催化Suzuki偶联反应在工业化应用方面的一些新进展。 相似文献
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纤维素氧膦-钯络合物催化合成二元酮化物的研究 总被引:1,自引:1,他引:0
本文首次采用纤维素氧膦-钯络合物为催化剂,以丙酮为溶剂,有机锡试剂与二元酰氯偶联合成二元酮化物.该反应具有催化活性高、选择性强、反应条件温和、催化剂可以重复使用、在空气中稳定等特点,是由易得二元酸合成二元酮的新方法. 相似文献
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Giampietro Cum Raffaele Gallo Signorino Galvagno Agatino Spadaro And Pietro Vitarelli 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1984,34(8):416-422
The catalytic behaviour of palladium supported on aromatic polyamides was studied in the liquid phase hydrogenation of benzoyl chloride at 1 atm total pressure and between 348 and 408 K. The specific activity of the catalysts as a function of palladium concentration was found to increase with metal loading. It is suggested that palladium in a metallic state is the active site for the acid chloride hydrogenation. A decrease in the reaction rate has been observed at the highest temperatures indicating that under these conditions the availability of hydrogen becomes the rate determining step. Results on the liquid phase hydrogenation of acyl- and aroyl-chlorides are reported. No strong influence of the nature of the substituents was observed on reaction parameters. 相似文献