杂多化合物膜的制备及催化作用

Heteropoly compounds (HPC), a kind of polyoxometallates, with their strong acidity and oxidative ability, are good homogeneous and heterogeneous catalysts in both acid-catalyzed and selective oxidation reactions, and have been widely used in petroleum and fine chemical industries. Owing to the diversity in their composition and structure, the catalytic properties of HPC can be altered in a wide range. Among them, the heteropolyanions with Keggin structure have been studied by far the most,especially on their applications in heterogeneous catalysis. However, since they are thermally unstable at high temperatures, their utilization in this field has been restricted. In the last ten years, inorganic membranes have been proved to be beneficial to heterogeneous catalytic processes for their high selectivity and good heat-conductivity. And the sol-gel method, one of the most common approaches to prepare inorganic membranes, is becoming mature. Here a sol-gel method to prepare a porous HPC membrane is reported. The catalytic performance of the membrane was tested through a model reaction, the selective oxidation of t-BuOH.     

杂多化合物及其负载型催化剂的研究进展

详细介绍了杂多化合物及其负载型催化剂的研究进展并对不同的催化剂载体进行了总结。对杂多化合物与载体之间的相互作用以及杂多化合物催化剂的反应机理进行了讨论。     

铜催化不饱和化合物硅加成反应的研究进展

有机硅化合物不仅是十分有用的功能分子,而且是非常重要的有机合成中间体,在一定条件下通过适当的化学方法,可以转化为很多其它有用的功能性化合物.到目前为止,已经陆续发展了各种过渡金属参与的催化方法来制备有机硅化合物,其中铜催化不饱和化合物的硅加成反应是一种重要的合成有机硅化合物的方法.从不饱和化合物的种类出发,主要涉及α,β-不饱和化合物、亚胺、Morita-Baylis-Hillman(MBH)醇类化合物、对苯醌甲基化合物、α,β-不饱和炔羰化合物以及α,β-不饱和砜类化合物,综述了近几年在铜催化作用下这些不饱和化合物通过硅加成反应合成有机硅化合物的最新研究进展,有利于加深对铜催化硅加成反应的理解.     

P,N配位的环钯配合物催化Suzuki偶联合成含氟液晶化合物的研究

合成了P,N配位的环钯配合物1-2.它们不仅是在室温下高效催化对溴甲苯与对氟苯硼酸的交叉偶联反应而且也是合成含氟液晶化合物的高效催化剂.在最佳反应条件下,含氟液晶化合物的产率都超过90%.     

钯／阴离子交换树脂对硝基化合物催化加氢的取代基效应

本文研究了聚苯乙烯系强碱性阴离子交换树脂负载的钯催化剂对取代硝基苯催化加氢的性能,结果表明,取代基的电子性质及空间位置对加氢速率影响很大;反应活化能与取代常数σ之间呈线性关系:E_1=-20.7σ+47.0在该反应体系中存在补偿效应:log A_(red)=0.14E_a-6.86     

FePVAsMo杂多化合物膜催化低碳醇选择氧化反应的研究

用组合法合成HxFe01.7P1.1V1.1As0.44-1.1Mo2Oy杂多化合物，并将其以浸渍法负载于多孔钛片上制成催化剂膜，在自制膜式反应釜中选择性催化氧化低碳醇，探讨了As,Fe含量及不同膜焙烧温度对催化剂催化性能的影响；用TPR，IR，TG－DTA对杂多化合物进行表征。结果表明，Fe的引入，可大大提高催化剂的活性和反应的选择性；As的引入，使催化剂的氧化脱氢能力大幅提高；膜焙烧温度为400℃时，催化剂的活性，选择性与稳定性最佳。组成为HxFe0.84P1.1V1.1As0.75Mo12Oy的杂多化合物膜催化剂对低碳醇具有良好的催化氧化活性，稳定性及再生能力。在适宜的条件下催化乙醇氧化，乙醛收率可达95．2％，对丙醇，丁醇也有良好的催化活性。     

烷基膦酸二烷基酯的固—液相转移催化合成及其阻燃性能

烷基膦酸二烷基酯的固－液相转移催化合成及其阻燃性能王筱梅＊杨平蔡庆华鲍猛（山东建筑材料工业学院应用化学系济南２５００２２）关键词烷基膦酸二烷基酯，合成，相转移催化，阻燃性１９９６－０８－１２收稿，１９９７－０３－０３修回烷基膦酸二烷基酯是一类具有实用...     

Surprising Formation of Chlorinated Butenolides from Dialkyl Acetylenedicarboxylates and Hexachloro­acetone in the Presence of Triphenyl Phosphite

Triphenyl phosphite reacts smoothly with dialkyl acetylenedicarboxylates and hexachloroacetone to produce alkyl 2‐(dichloromethylene)‐2,5‐dihydro‐5‐oxo‐4‐(trichloromethyl)furan‐3‐carboxylates in good yields.     

Reactions with aziridines XXI The (Michaelis-)arbusov reaction with N-acyl aziridines and other amidoethylations at phosphorus.

Heating trialkyl phosphites with N-acyl aziridines produces dialkyl 2-amidoethyl-phosphonates bearing one of the phosphite alkyl groups on nitrogen. Other alkoxy phosphines behave analogously. Dialkyl phosphites furnish the same type of products devoid of the N-alkyl group.     

Reactions of 5-Functionalyzed 2-(1-Haloethyl)furans with Sodium Diethylphosphite and Trialkyl Phosphites

5-(1-Haloethyl)furan-2-carboxylic acid derivatives react with sodium dialkyl phosphite, tri-alkyl phosphite in two directions to form phosphonates and alkenes. The alkene fraction in the reaction pro-ducts diminishes as the electron-acceptor power of the 2-substituent in the ring increases in going from dialkylamide to ether and then to nitrile. 5-Bromoethyl-2-cyanofuran reacts with sodium diethyl phosphite to give no other products than those formed by halogenophilic attack, implying a significant withdrawal of the electron density from the bromine atom in this compound.     

A New Route to Some Novel Phosphole Derivatives

Abstract

Previous work has shown that the unstable five co-ordinate phospholes (1; R=alkoxy, R′=alkyl) produced in the reaction of trialkyl phosphites with a two molar equivalent of dimethyl acetylenedicarboxylate can be converted into the novel phospholes (2; R=alkoxy) by treatment with hydrogen bromide at low temperature. We have now shown that a similar approach can be used to generate the phospholes (2; R=alkyl, aryl) by using dialkyl alkylphosphonites or dialkyl arylphosphonites rather than trialkyl phosphites. However, the reduced stability of the phosphorane intermediates (1; R=alkyl, aryl, R′=alkyl) relative to those produced in the trialkyl phosphite reactions means that these trapping reactions are difficult to carry out successfully.     

Synthesis of dibenzo‐16‐crown‐5 compounds with pendant ester and ether groups

Structurally related dibenzo‐16‐crown‐5 lariat ethers with pendant ester and ether groups are prepared. Structural variations within the series of alkyl lariat ether esters include changes in the O‐alkyl group, attachment site and nature of the lipophilic group, and length of the spacer, which connects the ester group to the polyether framework. Also synthesized are bis(crown ether) diesters with two dibenzo‐16‐crown‐5 or two dicyclohexano‐16‐crown‐5 units and two ester groups connected to each other by a linker of varying length. Synthetic strategies for the preparation of these lariat ethers with pendant ester‐ and ether‐containing side arms are described.     

开链冠醚类似物的合成与研究I

Antipyrine derivatives I (Z = O, S; Z1 = CH2, CH2OCH2; n = 0, 1, 2, 3) were prepared as open-chain crown ether analogs. Thus, refluxing diethylene glycol ditosylate with 4-hydroxyantipyrine and K2CO3 in acetone for 15 h gave I (Z = O, Z1 = CH2OCH2). The activities of I as phase-transfer catalyst for iodination of 1-bromoctane with NaI, or KI were reported.     

5-Hydroxypentylammonium acetate as a reusable ionic liquid catalyzes tandem Knoevenagel-phospha-Michael reaction of aldehydes, malononitrile and phosphites

5-Hydroxypentylammonium acetate as a task-specific ionic liquid promotes efficient tandem Knoevenagel-phospha-Michael reaction of phosphite esters with aryl/heteroaryl/alkyl/salicylaldehydes and malonitrile/ethyl cyanoacetate at room temperature in short reaction times. This simple procedure allows a series of ??-phosphonomalonates and 4-substituted 2-amino-4H-chromenes with phosphonic acid dialkyl esters to be synthesized in good to high yields in the presence of an ionic liquid for the first time.     

Tuning the arrangement of mono-crown ether-substituted phthalocyanines in Langmuir-Blodgett films by the length of alkyl chains and the cation in subphase

Amphiphilic phthalocyanines with one crown ether and three alkyl chain substitutions can form stable monolayers on a water surface. This monolayer can be transferred to a substrate by a vertical dipping method. The arrangement of phthalocyanine molecules in LB films was affected by the length of alkyl chains and the coordination of alkali ions in crown ether. Davydov splitting was observed in the absorption spectra of the LB films of phthalocyanine with the shortest alkyl chain substitutions, and this splitting was affected by the alkali ions in the subphase.     

31P NMR Studies of Diethyl Phosphite Derived Nanocrystalline Hydroxyapatite

³¹P nuclear magnetic resonance (NMR) spectroscopy was used to determine the structure of the intermediate species of sol derived from triethyl phosphite, calcium diethoxide and acetic acid. NMR spectral data revealed that the reaction proceeds via a dialkyl phosphite intermediate. The use of a dialkyl phosphite precursor (diethyl phosphite) with calcium diethoxide eliminated the aging time required in triethylphosphite method and offered an effective sol-gel procedure for monophasic hydroxyapatite.