Mechanism of Cp<Subscript>2</Subscript>ZrCl<Subscript>2</Subscript>-catalyzed olefin hydroalumination by alkylalanes

The composition of intermediates of the Cp₂ZrCl₂-catalyzed hydroalumination of α-olefins by isobutylalanes (HAlBuⁱ ₂, AlBuⁱ ₃, ClAlBuⁱ ₂) was studied by dynamic ¹H and ¹³C NMR pectroscopy. The reaction of Cp₂ZrCl₂ with isobutylalanes affords the complex (Cp₂ZrHCl·HAlBuⁱ ₂)₂ responsible for α-olefin hydroalumination.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 311–322, February, 2005.     

Electrochemically formed fullerene-based polymeric films

The recent results of investigations involving the electrochemical formation of polymers containing fullerenes and studies of their properties and applications are critically reviewed. From a structural point of view, these polymers can be divided into four main categories including (1) polymers with fullerenes physically incorporated into the foreign polymeric network without forming covalent bonds, (2) fullerene homopolymers formed via [2+2] cycloaddition, (3) “pearl necklace” polymers with fullerenes mutually linked covalently to form polymer chains, and (4) “charm bracelet” polymers containing pendant fullerene substituents. The methods of electrochemical polymerization of these systems are described and assessed. The structural features and properties of the electrochemically prepared polymers and their chemically synthesized analogs are compared. Polymer films containing fullerenes are electroactive in the negative potential range due to electroreduction of the fullerene moieties. Related films made with fullerenes derivatized with electron-donating moieties as building blocks are electroactive in both the negative and positive potential range. These can be regarded as “double cables” as they exhibit both p- and n-doping properties. Fullerene-based polymers may find numerous applications. For instance, they can be used as charge-storage and energy-converting materials for batteries and photoactive units of photovoltaic cell devices, respectively. They can be also used as substrates for electrochemical sensors and biosensors. Films of the C₆₀/Pt and C₆₀/Pd polymers containing metallic nano-particles of platinum and palladium, respectively, effectively catalyze the hydrogenation of olefins and acetylenes. Laser ablation of electrochemically formed C₆₀/M and C₇₀/M polymer films (M=Pt or Ir) results in fragmentation of the fullerenes leading to the formation of hetero-fullerenes, such as [C₅₉M]⁺ and [C₆₉M]⁺.Dedicated to Professor Dr. Alan M. Bond on the occasion of his 60th birthday.     

Fe_2O_3／ZrO_2催化剂上一氧化碳加氢反应制低碳烯烃──I．催化剂反应性能及反应过程中铁物相的变化

用浸渍法制得一系列不同铁负载量的Ｆｅ２Ｏ３／ＺｒＯ２催化剂，应用催化反应评价结合穆斯堡尔谱对催化剂的ＣＯ加氢反应性能、催化剂活性相结构及催化剂铁物种在合成气反应过程中的物相变化进行了研究．结果表明，铁负载量的大小对于Ｆｅ２Ｏ３／ＺｒＯ２催化剂的Ｆ－Ｔ反应催化性能有很大影响，铁负载量适当时，Ｆｅ２Ｏ３／ＺｒＯ２催化剂铁锆间适当的强相互作用使得催化剂在保持较高催化活性的同时高选择性地生成低碳烯烃，产物分布偏离Ｓｃｈｕｌｚ－Ｆｌｏｒｙ分布规律．     

Synthesis and transformations of metallacycles. 30. Aluminacyclopentanes in the synthesis of secondary and tertiary alcohols

A method for the synthesis of secondary and tertiary alcohols was developed. The method is based on cycloalumination of olefins with trialkylalanes in the presence of Zr-containing catalysts followed by the CuCl-catalyzed in situ reaction of the corresponding aluminacyclopentanes with aldehydes or ketones.     

二氧化碳多相催化加氢的新进展

就近年来关于ＣＯ２活化、几个重要的ＣＯ２多相催化加氢反应及廉价氢的供给的研究进展进行综述。参考文献３４篇。     

手性奎宁-卟啉锰催化剂的合成及其催化性能

为了寻找催化活性、相转移活性和手性诱导为一体的卟啉配体[1-4],我们把卟啉和手性相转移源连结起来,用奎宁-卟啉化合物作配体[5],考察其锰 配合物为催化剂对烯烃环氧化反应的催化性能。奎宁-卟啉锰 配合物结构式如下:1　实验部分1.1　试剂和仪器苯乙烯和α-甲基苯乙烯在氮气保护下减压蒸馏处理。氧源ＮａＯＣｌ的浓度由碘量法测定。其余试剂均为化学纯,色谱标样环氧苯乙烯和α-甲基环氧苯乙烯按文献[6]方法合成。奎宁-卟啉配体按文献[5]合成。260-50型红外光谱仪,ＫＢｒ压片;ＵＶ-3000型紫外可见光谱仪,溶剂ＤＭＦ;ＭＴ-3型ＣＨＮ元素…     

Water/Oil Biphasic Hydroformylation of Higher Olefins over a TPPTS-Rh/SiO2 Catalyst

A novel TPPTS-Rh/SiO2 catalyst, prepared by directly modifying a heterogeneous highsurface-area Rh/SiO2 catalyst with water-soluble TPPTS ligands, could decrease the resistance of mass transfer in water/oil biphasic media for the hydroformylation of higher olefins. The catalytic performance for hydroformylation on this biphasic TPPTS-Rh/SiO2 catalyst system was higher than those of the traditional biphasic HRhCO(TPPTS)3 systems, owing to the chemical bonds between the highly dispersed Rh metal particles and the TPPTS ligands. The catalyst system is applicable for hydroformylation of higher olefins such as 1-dodecene.     

Construction of substituted benzene rings by palladium-catalyzed direct cross-coupling of olefins: a rapid synthetic route to 1,4-naphthoquinone and its derivatives

Ring the changes: The direct cross-coupling of electron-deficient 1,4-benzoquinone or its derivatives with electron-rich alkyl vinyl ethers proceeds in a tandem manner to produce substituted benzene rings with good selectivity and in good to excellent yields. The reaction has the potential for the rapid synthesis of diverse substituted benzene rings as it is not limited by substituent effects.     

Polymer bound glutamic acid salicylaldehyde Schiff‐base complex ­catalyst for oxidation of olefins with ­dioxygen

The polymer bound Schiff‐base ligand (PS‐SalGlu) has been prepared from polystyrene bound salicylaldehyde and glutamic acid, and its complex (PS‐SalGlu‐Co) has also been synthesized. The polymer ligand and its complex were characterized by infrared spectroscopy, small area X‐ray photoelectron spectroscopy, and inductively coupled plasma‐atomic emission spectro (ICP‐AFS). In the presence of the complex, cyclohexene can be effectively oxidized by molecular oxygen without reductant. The long‐chain linear aliphatic olefins, such as 1‐octene, 1‐decene, 1‐dodecene and 1‐tetradecene, can be directly oxidized by molecular oxygen catalyzed by PS‐SalGlu‐Co, which affords the 1,2‐epoxy alkane. Copyright © 2001 John Wiley & Sons, Ltd.