Selective oxidation of olefins and aromatic alcohols with tert‐butylhydroperoxide catalyzed by polymer‐anchored transition‐metal complexes

Three polymer‐anchored metal complexes (Co, Cu, and Pd) were synthesized and characterized. The catalytic performance of these complexes was tested for the oxidation of olefins and aromatic alcohols. These complexes showed excellent catalytic activity and high selectivity. These complexes selectively gave epoxides and aldehydes from olefins and alcohols, respectively. Individually, the effect of various solvents, oxidants, substrate oxidant molar ratios, temperatures, and catalyst amounts for the oxidation of cyclohexene and benzyl alcohol were studied. Under optimized reaction conditions, 96, 81, and 71% conversions of cyclohexene and 86, 79, and 73% conversions of benzyl alcohol were obtained with Co(II), Cu(II), and Pd(II) catalysts, respectively. The catalytic results reveal that these complexes could be recycled more than five times without much loss in activity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

希夫碱类金属配合物催化剂催化氧化烯烃研究进展

分析了希夫碱金属配合物的结构特点及其催化氧化烯烃的研究现状,阐述了用于均相催化氧化的希夫碱、固载型希夫碱金属配合物催化剂的分类及其在氧化烯烃领域的应用研究。通过分析希夫碱类小分子金属配合物催化氧化烯烃的缺陷,得出非均相的负载型希夫碱类金属配合物催化剂是目前主要发展方向的结论。     

Characterization and catalytic activity of polymer supported ruthenium Schiff base complexes towards catechol oxidation

Ruthenium(III) complexes of the Schiff bases formed by the condensation of polymer bound aldehyde and the amines, such as 1,2‐phenylenediamine (PS‐opd), 2‐aminophenol (PS‐ap), and 2‐aminobenzimidazole (PS‐ab) have been prepared. The magnetic moment, EPR and electronic spectra suggest an octahedral structure for the complexes. The complexes of PS‐opd, PS‐ap, and PS‐ab have been assigned the formula [PS‐opdRuCl₃(H₂O)], [PS‐apRuCl₂(H₂O)₂], [PS‐abRuCl₃(H₂O)₂], respectively. These complexes catalyze oxidation of catechol using H₂O₂ selectively to o‐benzoquinone. The catalytic activity of the complexes is in the order [PS‐abRuCl₃(H₂O)₂] ? [PS‐opdRuCl₃(H₂O)] ? [PS‐apRuCl₂(H₂O)₂]. Mechanism of the catalytic oxidation of catechol by ruthenium(III) complex is suggested to take place through the formation of a ruthenium(II) complex and its subsequent oxidation by H₂O₂ to the ruthenium(III) complex. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Synthesis,characterization and sulfide oxidation activity of vanadyl Schiff base complexes anchored on MCM-41

Vanadyl Schiff base complexes covalently attached on the surface of MCM-41 have been synthesized by anchoring Schiff base and subsequent reaction with VO(acac)₂. XRD, nitrogen adsorption and desorption, UV-visible spectroscopy and FT-IR show that vanadyl Schiff base complexes were successfully anchored on the surface of MCM-41 and the mesopore ordering decreased after the anchoring. The so-prepared heterogeneous catalysts have showed high activity for sulfide oxidation.     

Polystyrene anchored vanillin Schiff base—Complexation and ion removal studies

A set of six new polystyrene anchored metal complexes have been synthesized by the reaction of the metal salt with the polystyrene anchored Schiff base of vanillin. These complexes were characterized by elemental analyses, Fourier transform infrared spectroscopy, diffuse reflectance studies, thermal studies, and magnetic susceptibility measurements. The elemental analyses suggest a metal : ligand ratio of 1 : 2. The ligand is unidentate and coordinates through the azomethine nitrogen. The Mn(II), Fe(III), Co(II), Ni(II), and Cu(II) complexes are all paramagnetic while Zn(II) is diamagnetic. The Cu(II) complex is assigned a square planar structure, while Zn(II) is assigned a tetrahedral structure and Mn(II), Fe(III), Co(II), and Ni(II) are all assigned octahedral geometry. The thermal analyses were done on the ligand and its complexes to reveal their stability. Further, the application of the Schiff base as a chelating resin in ion removal studies was investigated. The polystyrene anchored Schiff base gave 96% efficiency in the removal of Ni(II) from a 20‐ppm solution in 15 min, without any interference from ions such as Mn(II), Co(II), Fe(III), Cu(II), Zn(II), U(VI), Na⁺, K⁺, NH₄⁺, Ca²⁺, Cl^?, Br^?, NO₃^?, NO₂^?,and CH₃CO₂^?. The major advantage is that the removal is achieved without altering the pH. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1536–1539, 2005     

Covalently anchored metal complexes onto silica as selective catalysts for the liquid phase oxidation of benzoins to benzils with air

Benzoins are selectively oxidized to benzils in the presence of covalently anchored metal complexes onto silica by stirring in toluene at 100 °C in air atmosphere. Silica functionalized metal complexes have been prepared by the complexation of organically modified silica (imine) with Pd(OAc)₂ (Cat 1), Co(OAc)₂ (Cat 2) and Ni(OAc)₂ (Cat 3). Cat 1, 2 and 3 have been characterized by FTIR, thermal analysis and AAS analysis. Cat 1 was found to be most active, stable and recyclable under the reaction conditions. It was also characterized by SEM and TEM.     

Oxidation of alkanes with hydrogen peroxide catalyzed by Schiff base complexes covalently anchored to polyoxometalate

The catalytic activity of a hybrid compound [Fe(salen)-POM] (1) consisting of metallosalen moiety, [Fe^III(salen)Cl], covalently linked to a Keggin type polyoxometalate, K₈SiW₁₁O₃₉ (POM), in the oxidation of hydrocarbons with hydrogen peroxide was investigated. Reaction products were identified by gas chromatography and satisfactory yields were obtained. While, the Fe(salen)-POM catalyst showed high catalytic activity and product selectivity in the oxidation reactions, the metallosalen alone, [Fe^III(salen)Cl], showed very poor catalytic activity in these reactions. The ability of various transition metal ions in this oxidation system was also investigated. Among a series of hybrid compounds, Fe(salen)-POM showed the highest activity.     

电有机合成3,5-二溴水杨醛缩丝氨酸过渡金属配合物的研究

研究了3,5-二溴水杨醛缩丝氨酸过渡金属配合物的绿色电化学合成工艺。以3,5-二溴水杨醛及丝氨酸为原料,无水乙醇为溶剂,合成3,5-二溴水杨醛缩丝氨酸席夫碱。以席夫碱为原料,分别以金属铜、镍、锌片等为阳极,铂片为阴极,乙腈为溶剂,季铵盐为电解质,通入直流电电解,获得了3,5-二溴水杨醛缩丝氨酸席夫碱铜(Ⅱ)、镍(Ⅱ)、锌(Ⅱ)配合物,同时利用正交实验优化了配合物电化学合成工艺条件。利用红外光谱、紫外光谱、热分析等手段对过渡金属配合物进行结构表征,结果表明达到了预期的合成目的。     

Efficient and selective oxidation of alcohols catalyzed by oxo-rhenium complexes

This work reports the catalytic activity of several oxo-rhenium complexes in the oxidation of alcohols, using a sulfoxide as oxidant agent. The catalytic system bis(4-chlorophenyl) sulfoxide/ReOCl₃(PPh₃)₂ (10 mol%) proved to be efficient for the oxidation of primary and secondary alcohols to the corresponding aldehydes and ketones. The primary alcohols are selectively oxidized to the corresponding aldehydes with no further oxidation to acids. The bis(4-chlorophenyl) sulfide, isolated as by-product in high yields, can be used as a substrate in other reactions or can be oxidized and reused in this procedure.     

二硫代肼基甲酸配合物及其席夫碱衍生物的合成

合成了二硫代肼基甲酸镉与镍的配合物以及由二硫代肼甲酸与环己酮１，４－双（２’－甲酰基苯基）－１，４－二氧杂丁烷缩合的两种新的含硫席夫碱衍生物，所有化合物都进行了表征，确定了它们的组成，且对两种席夫碱衍生物的性质进行了初步研究。     

钼铋复合金属氧化物催化低碳烯烃选择氧化制备醛类研究进展

低碳烯烃选择氧化制备醛类等含氧化合物是生产有机化工中间体及产品的关键步骤,钼铋复合金属氧化物因其优异的催化性能在相关工业界和学术界受到广泛关注,然而目前关于该催化剂上选择氧化反应机制和催化反应本质等科学问题的认识尚未形成统一理论。本文系统综述了钼铋复合金属氧化物在催化低碳烯烃选择氧化制备醛类反应中的研究进展,包括催化剂微观结构的三种调控手段,即主组分钼酸铋物相结构、助剂及载体等对反应性能的影响,并对反应机理进行了深入讨论与总结。最后展望了钼铋复合金属氧化物在该选择氧化反应中的发展前景,为钼铋复合金属氧化物修饰改性及开发高效低碳烯烃选择氧化制含氧化合物催化剂提供思路。     

负载金属Salen配合物催化剂在催化反应中的应用研究进展

对负载金属salen配合物从负载方法、适用反应等方面的研究成果进行了总结,对不同负载方法的优缺点进行了阐述,并对这类催化剂工业化应用前景和拟解决问题进行了探讨。     

Interpolymer complexes of novel linear and crosslinked acrylic acid–Schiff base copolymers

Novel linear and crosslinked copolymers of acrylic acid and Schiff base, containing the amine groups in the main chain and the carboxylic groups in the side chain, have been synthesized by the Michael addition reaction followed by radical copolymerization. The copolymers that exhibited poly(ampholyte–electrolyte) behaviour were used to prepare complexes by reaction with anionic (poly(acrylic acid), poly(styrene sodium sulfonate)), cationic (polyethyleneimine, poly(hexamethylene guanidine)) and non‐ionic (poly(N‐vinylpyrrolidone), poly(ethylene glycol), poly(vinyl alcohol)) polymers. The influence of external factors, such as solvent quality, temperature, pH and ionic strength, on phase (coil–globule) and volume (swelling–collapse) transitions has been studied. © 2003 Society of Chemical Industry     

Fluorous biphase oxidation of ethyl benzene and benzyl alcohol catalyzed by perfluoroalkyl phthalocyanine complexes

BACKGROUND: Ketones and aldehydes are important organic chemicals as intermediates for the pharmaceutical and fine‐chemical industries. The existing oxidation reactions to obtain ketones and aldehydes are no longer sustainable because of the large amount of waste generated and use of stoichiometric reagents: a cleaner catalytic oxidation system needs to be developed. RESULTS: The experimental results show that cobalt (II) tetra‐(perfluorohexyl) phthalocyaninate delivered a high catalytic activity for the oxidation of ethyl benzene (35% conversion and 86% selectivity to acetophenone) at 90 °C under ambient pressure of oxygen. The catalyst could be recycled for at least four runs. For the oxidation of benzyl alcohol to benzaldehyde, a conversion of 6% was achieved but with a selectivity of 100% at 90 °C under 2 × 10⁵ Pa O₂. CONCLUSION: Perfluoroalkyl metallophthalocyanines can be used for the fluorous biphasic oxidation of ethyl benzene and benzyl alcohol with molecular oxygen. The cobalt (II) tetra‐(perfluorohexyl) phthalocyaninate exhibited the highest catalytic activity for the oxidation of ethyl benzene. The catalytic oxidation of benzyl alcohol using our method may be feasible in industrial applications. Copyright © 2009 Society of Chemical Industry     

L-缬氨酸席夫碱金属配合物的合成及光催化性质

以L-缬氨酸和香兰素为起始原料,设计并合成了3种L-缬氨酸席夫碱金属配合物C_(13)H_(20)Fe~(2+)NO_6、C_(13)H_(20)Cu~(2+)NO_6和C_(13)H_(20)Sn~(2+)NO_6,采用1H NMR、MS(EI)和元素分析等表征其结构。以3种L-缬氨酸席夫碱金属配合物作为光催化剂,研究25℃下,C_(13)H_(20)Fe~(2+)NO_6、C13H20Cu2+NO6和C13H20Sn2+NO6催化剂在甲醇与水混合溶液中的亚甲基蓝降解性能。结果表明,3种催化剂对亚甲基蓝均有降解活性,其中,C13H20Sn2+NO6催化剂的亚甲基蓝降降解性能最好,预测这是一类潜在的环保性光催化材料。     

Enantioselective hydroformylation of olefins catalyzed by rhodium(I) complexes of chiral phosphine–phosphite ligands

Using Rh(I) complexes of chiral phosphine–phosphites, hydroformylation of such a variety of olefins as aryl–substituted, alkyl–substituted, and heteroatom–substituted ones proceeded in high enantioselectivity. A trigonal bipyramidal RhH(CO)₂(phosphine–phosphite) complex is suggested as the active species, in which the hydride and the phosphite moiety are located at the apical positions. This revised version was published online in June 2006 with corrections to the Cover Date.     

席夫碱稀土铈配合物的合成、表征及抗菌活性

利用四乙酰丙酮铈配合物[Ce（acac）4]和Salphen型水杨醛缩邻苯二胺（Schiff碱）合成了双齿Salphen型席夫碱铈金属配合物（SB-Ce）,用红外光谱（FTIR）、紫外-可见光谱（UV-Vis）和差热-热重（TG-DTA）分析进行结构表征,将SB-Ce配合物用于抑菌活性实验。结果表明,SB-Ce对大肠杆菌、枯草杆菌、金黄色葡萄球菌和酵母菌都有一定的抑菌活性,其中对金黄色葡萄球菌的抑菌性最好。     

含二茂铁基Schiff碱及其金属 配合物的合成、表征及抑菌活性

通过双乙酰基二茂铁和水合肼合成双乙酰基二茂铁双肼腙配体,然后分别与Cu(Ⅱ),Ni(Ⅱ),Zn(Ⅱ),Pb(Ⅱ),Cd(Ⅱ)合成金属配合物。配体及其金属配合物通过摩尔电导、元素分析、IR和1HNMR进行了表征。所有化合物进行了抗菌活性测试,结果表明,化合物都具有一定的抗菌活性,金属配合物2a~2f比其配体有更高的抗菌活性,其中,CdL(CH3COO)2(2f)的抗菌活性最高。     

二[(三甲基硅基)亚甲基]锡(Ⅳ) Schiff碱配合物的合成和结构表征

用二[(三甲基硅基)亚甲基]二氯化锡和水杨醛缩氨基酸Schiff碱,以1∶1的物质的量比在三乙胺存在下进行反应,合成了5个新的标题化合物,利用IR、1HNMR和MS对它们的组成和结构进行了表征。测试结果表明,在目标化合物的分子中,中心锡原子与氮原子发生配位,形成了五配位的三角双锥结构。