Synthesis of New Apomorphine Derivatives Containing Halogen (CI and Br) in RING-D#

A series of 8-halogen- (Cl,Br)-substituted apocodeines was prepared by the rearrangement of the corresponding 1-halogen-substituted codeines. O-demethylation of the apocodeines yielded the 8-halogenoapomorphines. 8-bromo-substituted morphothebaine derivatives have been conveniently prepared by direct bromination.     

负载型杂多酸催化剂的研究进展

本文介绍了以活性炭，SiO2，γ-Al2O3,TiO2,MCM-4分子筛，炭化树脂，活性炭纤维，膨润土等为载体制备负载型杂多酸催化剂的方法及在国内外的应用情况，并展望了未来的研究方向。     

Photoluminescence emission spectroscopic study of molybdenum-based heteropolyacid catalysts

Summary Photoluminescence emission spectroscopy studies of heteropolyacid (HPA) catalysts have been carried out. All the HPA samples gave rise to violet emission peak (emission peak I) at the same wavelength of 418 nm. However, a shoulder peak in the visible region (emission peak II) appeared at different wavelengths depending on the identity of the HPA sample. Photoluminescence emission peak (II) energies could be correlated with the negative differential resistance (NDR) peak voltages of nanostructured HPA monolayers measured using scanning tunneling microscopy (STM).     

杂多酸催化作用下氢醌与甲醇生成氢醌单甲醚反应机理的探讨

氢醌单甲醚(HQMME)是单体聚合的高效阻聚剂,又是重要化工原料.以氢醌(HQ)和硫酸二甲酯为原料的经典合成法,由于硫酸二甲酯的剧毒和价格昂贵,正在被HQ和甲醇的催化合成法所代替.有报道,杂多酸(HPA)对该反应有优良催化性能.本文考察了四种HPA对HQ和MeOH生成HQMME的催化性能及其影响因素,并探讨了反应机理.     

杂多酸引发四氢呋喃聚合反应

八十年代中、后期发现，杂多酸（ＨＰＡ）是阳离子聚合反应的良好引发剂［１，２］．ＨＰＡ是一类酸强度比浓硫酸还高的质子酸［３］，不仅具有易于制备，结构稳定，腐蚀性低，易溶于大多数有机溶剂的特点，更为重要的是，ＨＰＡ可以回收和重复使用．因此，ＨＰＡ作为一类...     

Esterification of phthalic anhydride with 1-butanol and 2-ethylhexanol catalyzed by heteropolyacids

Esterification of phthalic anhydride with 2-ethylhexanol and 1-butanol and ester decomposition of dioctyl phthalate (DOP) in presence of Keggin; H₃PW₁₂O₄₀, H₄SiW₁₂O₄₀, H₄SiMo₁₂O₄₀, Wells–Dawson; H₆P₂W₁₈O₆₂, H₆P₂W₁₇MoO₆₂ and Preyssler; H₁₄[NaP₅W₂₉MoO₁₁₀], H₁₄[NaP₅W₃₀O₁₁₀], type heteropolyacids have been investigated. The heteropolyacids with Preyssler and Wells–Dawson structures and their molybdenum substituted derivatives show higher activity in esterification and ester decomposition reactions than Keggin type heteropolyacids. A complete conversion of phthalic anhydride to dioctyl phthalate and dibutyl phthalate are achieved in 2 h in presence of molybdenum substituted Preyssler heteropolyacid. In the decomposition of dioctyl phthalate in the presence of Preyssler heteropolyacid, 2-ethylhexene is formed in quantitative yield.     

Nitration of Aromatic Compounds Catalyzed by Divanadium-Substituted Molybdophosphoric Acid,H<Subscript>5</Subscript>[PMo<Subscript>10</Subscript>V<Subscript>2</Subscript>O<Subscript>40</Subscript>]

Summary. The nitration of aromatic compounds was carried out in the presence of divanadium-substituted molybdophosphoric acid, H₅PMo₁₀V₂O₄₀, as catalyst and a mixture of nitric acid and acetic anhydride as nitrating agent. In the presence of this heteropolyacid the ortho- and para-nitro compounds were obtained in good to excellent yields under mild reaction conditions.     

Direct reductive amination and selective 1,2-reduction of α,β-unsaturated aldehydes and ketones by NaBH4 using H3PW12O40 as catalyst

A simple and convenient procedure for direct reductive amination of aldehydes and ketones with sodium borohydride is described. The reaction has been carried out in methanol in the presence of a catalytic amount of H₃PW₁₂O₄₀ (0.5 mol %). α,β-Unsaturated aldehydes and ketones can be easily converted into the corresponding allyl alcohols by reaction with H₃PW₁₂O₄₀ (0.5 mol %)/NaBH₄.     

Catalytic Chemistry of Supported Heteropolyacids and Their Applications as Solid Acids to Industrial Processes

This article reviews recent research and development of supported heteropolyacid (HPA) catalysts; focusing on the acidic and catalytic properties. First the basic knowledge of solid HPAs is provided briefly to facilitate understanding of heterogeneous catalysis of HPAs. Secondly, the structure as well as the physical and chemical properties of supported HPA catalysts is described. Especially the layer structure of HPA dispersed on the surface of SiO₂ and the changes in the surface acidity with the loading level of HPA are discussed. For this purpose, temperature programmed desorption of benzonitrile devised by Okuhara and Kamiya’s group is useful. This method is capable to assess the surface acidity of the supported HPA, which controls the catalytic activity for the reactions proceeding by surface-type catalysis. Then, two new industrial processes developed by Showa Denko K. K. are described; (i) production of ethyl acetate from ethylene and acetic acid and (ii) oxidation of ethylene to acetic acid. Supported HPA catalysts are utilized for both processes, which were recently much improved by finely controlling the catalysts and reaction conditions.     

杂多酸引发四氢呋喃开环聚合反应Ⅵ.以环氧氯丙烷为促进剂

在以低浓度杂多酸(ＨＰＡ)催化四氢呋喃(ＴＨＦ)聚合反应中,我们曾采用环氧乙烷(ＥＯ)和环氧丙烷(ＰＯ)为促进剂,发现它们都具有很好的促进效果[1,2],并且活性相近.在以三氟化硼(ＢＦ3)为催化剂的四氢呋喃正离子开环聚合反应中,促进剂的活性次序为:ＥＣＨ(环氧氯丙烷)>ＰＯＥＯ[3].在ＨＰＡ催化ＴＨＦ聚合反应中,ＥＣＨ是否仍具有高的促进活性是本文研究的目的.1　原料及聚合操作ＴＨＦ的纯化见文献[4],ＥＣＨ的纯化见文献[5],十二磷钨杂多酸(ＰＷ12)的处理见文献[1],三氟醋酸酐的合成方法和聚合反应的操作均见前文[2].2　分析测试核磁共振…