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Majid M. Heravi Samaheh Sadjadi Hossein A. Oskooie Fatemeh F. Bamoharram 《Tetrahedron letters》2009,50(8):943-17
A new multi-component synthesis of 4-arylaminoquinazolines from the reaction of 2-aminobenzamide, orthoesters, and substituted anilines in the presence of catalytic amounts of Keggin-type heteropolyacids is reported. The effects of reaction conditions and different heteropolyacids have been studied. 相似文献
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Reaction of isatoic anhydride with aniline derivatives gave 2-amino-N-(aryl)benzamides.The latters reacted with phenyli-sothiocyanate in the presence of heteropolyacids in various solvents which afforded 3-(aryl)-2-thioxo-2,3-dihydroquinazolin- 4(1H)-one derivatives.The effects of various heteropolyacids including Preyssler and Keggin on the yields and reaction times have been investigated. 相似文献
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钼钒砷三元杂多酸氧化还原性能研究 总被引:5,自引:0,他引:5
杂多酸应用十分广泛 ,作为催化剂是迄今为止的一项最广泛、最重要、最具前途的应用。已经用杂多化合物作为催化剂实现工业化的大型项目有八个[1] ,创造了良好的经济效益和社会效益。杂多酸具有酸性和氧化性 ,作为酸型、氧化型或双功能催化剂 ,应用于许多均相和多相催化反应中。其中 ,具有 Keggin结构的杂多酸显示出良好的催化活性 ,是被广泛应用的酸种之一。杂多酸组成元素众多 ,可以通过调变元素的组成和比例来调变其氧化还原性 ,以适应各种不同的催化需要 ,这对于开发新型催化剂具有重要意义。本文合成了四种钼钒砷三元杂多酸 ,经表征确… 相似文献
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Nathalie Laronze Jean-François Moisan Catherine Roch-Marchal Feng-Xian Liu Gilbert Hervé 《Journal of Cluster Science》2002,13(3):355-368
Transition metal salts of heteropolyacids have been prepared taking into account the strong acidic and cation exchanging properties of the solid heteropolyacids. The exchange between protons and the transition metal cation is carried out by stirring a suspension of the hydrated heteropolyacid in a solution of the metal acetylacetonate complex in toluene. The exchange occurs on the surface of the solid particles and diffusion of protons and metal cations into the hydrated lattice leads to the substitution of all the protons. The method can be utilized in order to prepare supported vanadyl and copper molybdophosphates from supported heteropolyacids and they have been studied in the catalysis of the oxidative dehydrogenation of isobutyric acid. The effect of vanadyl counter-ions on the catalytic behavior is the same as observed with bulk catalysts but, on the contrary, copper supported molybdophosphate shows an acid catalytic activity not observed with bulk catalysts. 相似文献
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Abdelaziz GHERIB Ahmed AOUISSI Alain RIVES Michel FOURNIER Robert HUBAUT 《催化学报》2007,28(12):1041-1046
制备了用于正己烷临氢异构化的氧化硅担载的Keggin型杂多酸和还原态Pt-Ce氧化物催化剂.这些混合氧化物催化剂或单独使用,或与氧化硅担载的杂多酸催化剂一起使用.用X射线衍射、傅里叶变换红外光谱、傅里叶变换拉曼光谱、热重和N2物理吸附等方法表征在氧化、还原态和催化实验后的催化剂状态.本文的目的是在最佳反应条件(反应温度、还原温度和流量等)下,筛选出具有最好异构化收率的催化剂.结果表明,还原氧化物的存在不但有利于消除积炭,而且在反应期间能有效地维持氧化硅担载杂多酸的结构.从这些催化剂样品中,可以找到具有更好异构化活性和选择性的催化剂. 相似文献
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Polyoxometalates are an important class of environmentally friendly catalysts. The Keggin heteropolyacids containing tungsten or molybdenum addenda atoms have received great attention because they have attractive acid and redox properties, which may be easily tunable through changes in their composition and structure. The replacement of their protons by large radium cations makes insoluble the Keggin heteropolyacids and increases their surface area. On the other hand, the removal of tungsten or molybdenum atoms from the Keggin heteropolyanion generates vacancies, which can activate different organic substrates. Therefore, solid lacunar heteropolyacid salts are potentially active catalysts and selective in a plethora of reactions. These catalysts are used either in homo- or heterogeneous conditions. In this review, we wish would highlight recent advances achieved in the chemistry of lacunar Keggin heteropolyacids. We describe their use as solid, soluble or solid-supported catalysts in reactions of oxidation of alcohols and olefins, oxidative desulfurization and acid-catalyzed reactions such as acetalization, esterification, and transesterification. 相似文献
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K. I. Matveev E. G. Zhizhina V. F. Odyakov V. N. Parmon 《Russian Chemical Bulletin》1994,43(7):1142-1145
2-Methyl-1-naphthol is oxidized into 2-methyl-1,4-naphthoquinone (menadione) by air in the presence of vanadomolybdophosphoric heteropolyacids and their salts. The reaction proceeds in a biphasic system, and the yield of menadione is up to 85 %. The influence of the composition of the heteropolyacids on the rate and the selectivity of the reaction was studied, and the reaction mechanism was proposed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1208–1211, July, 1994. 相似文献
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硅钼钒和硅钨钒杂多酸催化过氧化氢直接氧化苯制苯酚的活性研究 总被引:4,自引:0,他引:4
以自制的两种Keggin型杂多酸,硅钼钒杂多酸和硅钨钒杂多酸作催化剂,冰醋酸作溶剂,过氧化氢作氧化剂,研究了由苯直接羟基化制苯酚的催化活性,发现对于所研究的体系,即苯为0.02mol,过氧化氢为0.16mol,冰醋酸为0.24mol,当杂多酸的用量为0.10~0.15mmol、反应温度323K、反应时间80min时,硅钼钒和硅钨钒上苯酚的收率分别可达17.2%和4.3%,选择性达90.3%和87.4%. 相似文献
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An efficient method for the preparation of 1,3-dioxolanes via the coupling of epoxides with ketones catalyzed by heteropolyacids at ambient temperature has been described. 相似文献
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《Vibrational Spectroscopy》2007,43(2):435-439
The sorption of gaseous ammonia into solid polyoxometalates such as the Keggin (H4SiMo12O40, H4SiW12O40 and H3PW12O40) and Dawson type (H6P2W18O62) heteropolyacids was studied. The combination of microbalance measurements and FT-IR spectroscopy confirmed the formation of diammonium ion N2H7+ in the bulk of heteropolyacids of both types, which was found to depend on both the ammonia equilibrium pressure and sorption temperature. The diffusion coefficients of the ammonia molecules penetrating into the bulk of heteropolyacids were calculated. 相似文献
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Keggin杂多酸负载型催化剂研究及在有机合成中的应用 总被引:6,自引:0,他引:6
评述了负载型杂多酸Keggin结构催化剂的制备、表征及其表面作用机理, 阐述了在非均相催化酯化反应、Friedel-Crafts烷基化和酰基化反应、选择氧化、不对称催化反应、异构化反应、缩合反应、裂解反应、水合反应、脱水反应、水解反应、重排反应、Diels-Alder反应及醚化反应等作为探针反应的催化性能, 总结了重排反应、醇氧化等不同类型催化反应的反应机理和催化剂失活的主要原因以及影响负载型催化剂水热稳定性能的因素, 指出了负载型杂多酸Keggin结构催化剂研究中有待解决的问题及今后的发展方向.. 相似文献
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Heravi MM Sadjadi S Oskooie HA Shoar RH Bamoharram FF 《Molecules (Basel, Switzerland)》2007,12(2):255-262
Synthesis of 3,1,5-benzoxadiazepines from the condensation of o-phenylenediamine (o-PDA) and acyl chlorides in the presence of a catalytic amount of various heteropolyacids (HPAs) is reported. 相似文献
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An efficient (in terms of experiment and time) synthetic procedure for chloromethyl methyl ether (MOM-Cl) is described using heteropolyacids as catalysts. 相似文献
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Esterification of phthalic anhydride with 1-butanol and 2-ethylhexanol catalyzed by heteropolyacids 总被引:5,自引:0,他引:5
M. Arabi M. Mohammadpour Amini M. Abedini A. Nemati M. Alizadeh 《Journal of molecular catalysis. A, Chemical》2003,200(1-2):105-110
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. 相似文献
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Toutounchian Nafiseh Ahmadpour Ali Heravi Majid M. Bamoharram Fatemeh F. Ayati Ali Deymeh Fatemeh 《Research on Chemical Intermediates》2016,42(4):3283-3301
Research on Chemical Intermediates - Alkylation of benzene with 1-decene for production of linear alkylbenzene in the presence of nanotitania (n-TiO2)-supported Dawson heteropolyacids was studied.... 相似文献
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具有Dawson结构的钼钒磷杂多酸的制备和性质研究 总被引:20,自引:0,他引:20
本文报道用改良的分步处理合成方法, 直接制备了五种未见报道的2:18系列钼钒磷杂多酸, 详细考察了它们的生成条件. 经元素分析、电位滴定和差热热重分析确定阴离子的组成分别为[P2Mo17VO62]^7^-,[P2Mo16V2O62]^8^-,[P2Mo15V3O62]^9^-, [P2Mo14V4O62H2]^8^-, [P2Mo13V5O62H2]^9^-. 对五种杂多酸的热化学性质和碱度进行了讨论. 根据紫外、红外及X射线衍射结果讨论了它们的结构, 表明都属于具有Dawson结构的杂多化合物. 相似文献
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Samaheh Sadjadi Nargess Poormohammad Hossein A. Oskooie Yahya. Sh. Beheshtiha Fatemeh F. Bamoharram 《合成通讯》2013,43(17):3119-3125
The reaction of benzoyl chlorides with ethylenediamine in the presence of catalytic amounts of Keggin-type heteropolyacids led to oxidative conversion of benzoyl chlorides to the corresponding 2-imidazoles in good yields. 相似文献
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Pyrimidines are synthesized via a direct oxidative one-pot, three-component, reaction between 1,3-diketone, benzaldehydes, and ammonium acetate in the presence of catalytic amounts of Keggin-type heteropolyacids under refluxing conditions in good yields. 相似文献