Nanoscaled Copper Metal–Organic Framework (MOF) Based on Carboxylate Ligands as an Efficient Heterogeneous Catalyst for Aerobic Epoxidation of Olefins and Oxidation of Benzylic and Allylic Alcohols

Aerobic epoxidation of olefins at a mild reaction temperature has been carried out by using nanomorphology of [Cu₃(BTC)₂] (BTC=1,3,5‐benzenetricarboxylate) as a high‐performance catalyst through a simple synthetic strategy. An aromatic carboxylate ligand was employed to furnish a heterogeneous copper catalyst and also serves as the ligand for enhanced catalytic activities in the catalytic reaction. The utilization of a copper metal–organic framework catalyst was further extended to the aerobic oxidation of aromatic alcohols. The shape and size selectivity of the catalyst in olefin epoxidation and alcohol oxidation was investigated. Furthermore, the as‐synthesized copper catalyst can be easily recovered and reused several times without leaching of active species or significant loss of activity.     

Design and characterization of Dendrimer of MNPs as a novel,heterogeneous and reusable nanomagnetic organometallic catalyst for one‐pot synthesis of hydroxyl naphthalene‐1,4‐dione derivatives under solvent‐free conditions

A novel super acidic magnetic nanoparticle as catalyst was successfully synthesized. The preparation of this dendrimer sulfonic acid functionalized γ‐Fe₂O₃ magnetic core‐shell silica nanoparticles as a new recoverable and heterogeneous nanocatalyst was described. The new catalyst was characterized using various techniques such as scanning electron microscopy (SEM), energy dispersive spectrum (EDS), and thermo gravimetric synthesis (TGA). Moreover, we have examined the catalytic activity of the catalyst for one‐pot, efficient and facile synthesis of 2‐hydroxy‐1,4‐naphthoquinone derivatives via a three‐component condensation reaction of 2‐hydroxynaphthalene‐1,4‐dione, aromatic aldehydes and aniline derivatives. High yields of products, short reaction times, waste‐free, mild, ambient and solvent‐free reaction conditions are advantages of this protocol. Also, the catalyst can be easily recovered by an external magnetic and reused several times without significant loss of its catalytic activity.     

Concise route to a series of novel 3-(tetrazol-5-yl)quinoxalin-2(1H)-ones

This report presents a novel three step solution phase protocol to synthesize 3-(tetrazol-5-yl)quinoxalin-2(1H)-ones. The strategy utilizes ethyl glyoxalate and mono-N-Boc-protected-o-phenylenediamine derivatives in the Ugi-Azide multi-component reaction (MCR) to generate a unique 1,5-disubstituted tetrazole. Subsequent acid treatment stimulates a simultaneous Boc deprotection and intramolecular cyclization leading to bis-3,4-dihydroquinoxalinone tetrazoles. Direct oxidation using a stable solid-phase radical catalyst (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) with ceric ammonium nitrate (CAN) in catalytic fashion initiating aerobic oxidation, completes the entire procedure to generate a series of original unique bis-quinoxalinone tetrazoles. The method was also expanded to produce a bis-benzodiazepine tetrazole.     

HAp‐encapsulated γ‐Fe2O3‐supported dual acidic heterogeneous catalyst for highly efficient one‐pot synthesis of benzoxanthenones and 3‐pyranylindoles

A novel method is reported for the synthesis of benzoxanthenone and 3‐pyranylindole derivatives via one‐pot three‐component reactions using a newly synthesized HAp‐encapsulated γ‐Fe₂O₃‐supported dual acidic heterogeneous catalyst, as a reusable and highly efficient nanocatalyst. In this protocol the use of the nanocatalyst provided a green, useful and rapid method to generate products in short reaction times (4–20 min) and in excellent yields (87–96%). The paramagnetic nature of the catalyst provided a simple, trouble‐free and facile approach for the separation of the catalyst by applying an external magnet, and it could be used in eight cycles without significant loss in catalytic efficiency.     

Environmentally Friendly Preparation of Amidoalkyl Naphthols

A new, facile, and cost-effective process involving the solvent-free synthesis of amidoalkyl naphthols using a three-component, one-pot condensation reaction of β-naphthol, aromatic aldehyde, and amides in the presence of Al(H₂PO₄)₃ as heterogeneous catalyst under thermal conditions and microwave irradiation has been described. This new approach has the advantage of consistently excellent yields and short reaction times. The catalyst has shown a very stable catalytic activity in the reaction conditions and also can be recovered and recycled.     

新型钴酞菁接枝温敏聚合物的制备及性能

采用2,4,6-三氯-1,3,5-三嗪对四氨基钴酞菁进行改性,并以共价键接枝到聚N-异丙基丙烯酰胺上制得一种新型温敏性高分子催化剂——钴酞菁接枝温敏聚合物,并采用UV-Vis、TG等对其进行表征.对钴酞菁接枝温敏聚合物、温敏聚合物和小分子金属酞菁进行溶解性测试,结果表明与四氨基钴酞菁相比,所合成的钴酞菁接枝温敏聚合物能溶解于水和大多数有机溶剂,且该聚合物水溶液具有良好的温敏性,其最低临界溶解温度(LCST)为34.5℃.采用浊度法考察了不同比例的混合溶剂(乙醇/水、DMF/水)对LCST的影响,结果表明随着有机溶剂含量的增加,LCST先下降后升高,而当有机溶剂增加到一定程度时温敏性消失.本文还考察了钴酞菁接枝温敏聚合物对2-巯基乙醇的催化活性,结果表明随着温度升高,催化活性也不断提高,而当温度超过LCST时催化活性急剧下降,聚合物从溶液中析出.基于这些特性,该温敏聚合物负载酞菁作为一种新型的催化剂可实现均相催化、异相分离.     

Challenges and Development Opportunities for Catalytic Technologies in Petrochemical Industry in the 21st Century

The propellent drive and development opportunities for future catalytic technologies in petrochemical industry in the 21st century are reviewed in this paper. It focuses on the following five aspects:(1) The environmentally-friendly catalytic technologies, such as new technologies for the production of organic chemicals changing the raw material and synthetic process, the chemicals production replacing phosgene and hydrogen cyanide toxicant, and the conversion and utilization of organic wastes etc.(2) Utilization and development of cheaper light alkanes, for example, the chemical use of natural gas and the development technologies of methane chain, the production of acetic acid, ethylene and vinyl chloride from selective oxidation of ethane, as well as the manufacture of acrolein and acrylonitrile from the oxidation and ammoxidation of propane.(3) The new propylene-plus technologies of the low value higher olefins, such as catalytic cracking of C4,C5 olefins and metathesis of C4 olefin.(4) The technologies of high selective oxidation, e.g. production of propylene oxide with TS-1 molecular sieve, oxidation process by lattice oxygen and direct oxidation of benzene to phenol etc.(5) Development and application of novel catalytic materials, especially, mesopore molecular sieve materials for a larger molecule reaction, zeolite catalyst with MWW structure for alkylation of benzene and propylene, ionic liquid, and membrane reactor catalyst etc.Meanwhile,the challenging research subjects for future industrial catalysis and the several viewpoints for development strategy of new catalytic technologies are proposed. These viewpoints are as follows:(1) Catalysis discipline must be integrated with many other disciplines and should be multidisciplinary and transdisciplinary.(2) New preparation methods of catalytic materials must be originally developed.(3) The instrumentation having better time resolution and spatial resolution and applying under reaction conditions must be improved further.(4) Fundamental research for catalysis and catalytic theory must be enhanced.(5) Catalysis science must be closely integrated with catalytic reaction engineering.(6) Knowledge innovation and technical progress must be accelerated.(7) Scientific and technological co-operation between academic, industrial circles and public organization having a common interest in catalysis must be intensified.     

从三聚氰胺制得工业用深度脱硫的绿色纳米催化剂PMoV/Fe3O4/g-C3N4: 合成与表征

采用简便的化学浸渍法制备了新型磁性可分离的纳米复合物H5PMo10V2O40/Fe3O4/g-C3N4(PMoV/Fe3O4/g-C3N4),并进行了详细的表征,采用电位滴定法测定了催化剂酸性.该PMoV/Fe3O4/g-C3N4纳米复合物在硫化物选择氧化为砜或亚砜的反应中表现出较高的催化活性;考察了在优化反应条件下,它在含硫(包括二苯并噻吩DBT)模拟油或真实石油的催化氧化反应中的催化性能;特别考察了各种含氮化合物,以及1-环和2-环芳香烃作为共溶剂对DBT脱硫效果的影响.采用外加磁场即可方便地将该催化剂从反应混合物中分离和回收.选取最好的萃取剂,通过简单的倾滤就可很容易地将剩余反应物从产物中分离出来.该纳米催化剂具有高催化活性,且容易重复使用,至少可以重复使用4次而未见催化活性明显下降.     

A Facile and Efficient Solid Supported,One‐Pot Synthesis of Functionalized Piperidine Derivatives Catalyzed by Amberlite IRA400‐Cl Resin/I2/KI via Multicomponent Reaction

A facile and efficient one‐pot, solid supported synthesis of functionalized piperidine derivatives catalyzed by Amberlite IRA400‐Cl resin/I₂/KI via a multicomponent reaction of various aldehydes, aromatic amines, and 1,3‐dicarbonyl compounds has been achieved. The reaction has been carried out in a one‐pot reaction and Amberlite resin as a solid supported catalyst at room temperature. Shorter reaction time, easy workup, yield, and mild reaction condition make the novel synthetic strategy both practical and attractive.     

锰卟啉一次氯酸钠模拟体系中由芳醛制备相应羧酸

我们前文报道了在金属卟啉-次氯酸钠模拟体系中氧化苯甲醛时,金属卟啉结构与其催化性能的关系,结果表明:四(2.6-二氯)苯基卟啉合锰是稳定性能最好及活性较高的催化剂。本文进一步报道各种因素对反应的影响,并在此基础上提出了由芳醛合成相     

A simple and convenient method for synthesis of new aminonaphthoquinones derived from lawsone by catalytic multicomponent Mannich reaction

A clean, efficient and facile one-pot protocol was developed for the synthesis of a series of new aminonaphthoquinones derived from 2-hydroxy-1,4-naphthoquinone (lawsone) by three-component Mannich reaction using catalytic amount of p-TsOH in CH₃CN, at room temperature. At the present work, we improved the yield and significantly reduced the reaction time for several Mannich reactions with different amine and aromatic aldehydes using a non-expensive, mild catalyst and suitable solvent.     

Rapid aerobic oxidation of alcohols to carbonyl compounds with dioxygen using metallodeuteroporphyrin dimethyl esters as catalysts in the presence of isobutylaldehyde

A facile biomimetic method for rapid oxidation of alcohols to carbonyl compounds using dioxygen as the primary oxidant catalyzed by metallodeuteroporphyrin dimethyl ester [M(DPDME)] in acetonitrile as the reaction solvent and isobutylaldehyde as cocatalyst has been investigated. Among the M(DPDME) catalysts, where M = Fe(III), Co(II), Mn(III), Ni(II), Cu(II), and Zn(II), cobalt porphyrin was found to be the most active and effective catalyst. The catalytic system was widely used in the oxidation of various alcohols and especially exhibited excellent activity for oxidation of aromatic alcohols under mild conditions. Moreover, M(DPDME) was prepared from an improved facile method by chemical modification of natural hemin and an alternative mechanism for the aerobic oxidation of alcohols has been proposed and discussed. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:295–303, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21017     

锰卟啉一次氯酸钠模拟体系中由芳醛制备相应羧酸

前文报道了在金属卟啉-次氯酸钠模拟体系中氧化苯甲醛时,金属卟啉结构与其催化性能的关系,结果表明:四(2.6-二氯)苯基卟啉合锰是稳定性能最好及活性较高的催化剂。本文进一步报道各种因素对反应的影响,并在此基础上提出了由芳醛合成相应羧酸的新方法。     

Nitroarene catalyzed oxidation with sodium percarbonate or sodium perborate as the terminal oxidant

A new catalytic oxidation method for the preparation of aromatic carboxylic acids from methyl aryl ketones is reported. The method is an alternative to the haloform reaction; it is benign and affords the desired product without production of any harmful side products. The catalytic cycle is based on the use of an electron-deficient nitroarene as catalyst with either of the two cheap and green oxidants sodium percarbonate or sodium perborate. The method gives a good yield (87%) and shows excellent selectivity when the model substrate (acetophenone) is oxidized. A series of benzoic acids of industrial interest were prepared by means of this method.     

Silica iminopyridine-functionalized nanomaghemite enhances the oxygenation activity and durability of simple Co(II) salophen complex

A novel magnetically recoverable catalyst was produced by coordinative attachment of Co(II) salophen complex to silica iminopyridine (SIPy)-functionalized-γ-Fe₂O₃ magnetic nanoparticles (SMNP@SIPy/Co(II) salophen). The vibration spectra and compositional data provided sufficient evidences for the structural integrity of as-prepared organic–inorganic nanohybrid. The magnetic nanocatalyst proved to be an efficient and selective heterogeneous catalyst for oxidation of different benzylic alcohols and featured higher catalytic activity and stability than that of homogenous counterpart. A TOF of 151 h⁻¹ and TON of more than 322 were obtained for oxidation of 4-cholrobenzyl alcohol in this catalytic system. The supported catalyst could easily be recovered from the reaction mixture by an external magnetic field and reused for subsequent experiments with consistent catalytic activity.     

Novel ferrocene-based ionic liquid supported on silica nanoparticles as efficient catalyst for synthesis of naphthopyran derivatives

We report synthesis of silica nanospheres containing ferrocene-tagged imidazolium acetate (SiO₂@Im-Fc[OAc]) as efficient heterogeneous nanocatalyst for synthesis of naphthopyran derivatives under solvent-free conditions, based on modification of nano SiO₂ by ionic liquid with ferrocene tags and subsequent anion metathesis reaction. The synthesized novel nanocatalyst (SiO₂@Im-Fc[OAc]) was systematically characterized using Fourier-transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction analysis, and field-emission scanning electron microscopy. The catalytic activity of (SiO₂@Im-Fc[OAc]) was tested in one-pot three-component reaction of aromatic aldehydes, malononitrile, and 2-naphthol for facile synthesis of naphthopyran derivatives. To achieve high catalytic efficacy, the effects of various reaction parameters such as temperature, amount of catalyst, type of solvent, etc. were investigated. Furthermore, recovery and reuse of the nanocatalyst several times was demonstrated without appreciable loss in catalytic activity. The presented protocol offers several advantages, including green and ecofriendly nature, operational simplicity, higher yield, and easy recovery and reuse of the nanostructured catalyst. The workup of these very clean reactions involves only recrystallization of the product from ethanol and recovery of the catalyst by filtration.     

A facile synthesis of pyrano[2,3-d:6,5-d′]dipyrimidines via microwave-assisted multicomponent reactions catalyzed by β-cyclodextrin

A facile three-component reaction of aromatic aldehyde, 2,2-dimethyl-1,3-dioxane-4,6-dione, and 6-amino-1,3-dimethyluracil was developed for the first time using β-cyclodextrin (β-CD) as a macrocyclic host for aldehyde and an efficient catalyst that leads to a batch of novel pyrano[2,3-d:6,5-d′]dipyrimidines ( 4a-k ). The synthesis was accomplished with the aid of microwave irradiations in solvent-free conditions. The product obtained was in contrast to the previous report in which a similar reaction resulted in a mixture of benzylidenepyrimidine and bisaminopyrimidine analogs in the presence of triethylbenzylammonium chloride in an aqueous medium. The formation of the pyrano[2,3-d:6,5-d′]dipyrimidines may be in virtue of the property of β-CD to construct new C C and C X (where X = heteroatom) bonds. Reusability of the catalyst up to three runs without any noteworthy change in catalytic activity is one of the main features of the reaction. Other noteworthy features are good to excellent yields, eco-friendly procedure, non-column chromatographic purification, and mild conditions.     

The direct and enantioselective organocatalytic alpha-oxidation of aldehydes

The first direct enantioselective catalytic alpha-oxidation of carbonyls has been accomplished. The use of enamine catalysis has provided a new organocatalytic strategy for the enantioselective oxyamination of aldehydes, to generate alpha-oxyaldehydes, important chiral synthons for natural product and medicinal agent synthesis. The use of l-proline as the asymmetric catalyst has been found to mediate the oxidation of a large variety of aldehyde substrates with nitrosobenzene serving as the electrophilic oxidant. A diverse spectrum of aldehyde substrates can also be accommodated in this new organocatalytic transformation. While catalyst quantities of 2 mol % were generally employed in this study, successful oxidations conducted using catalyst loadings as low as 0.5 mol % are described.     

An efficient method for the multicomponent synthesis of multisubstituted pyridines,a rapid procedure using Au/MgO as the catalyst

Au/MgO proved to be a highly efficient and reusable catalyst for multicomponent coupling reactions at 70 °C. The synthesized multisubstituted pyridines were obtained in high yields and in short reaction times. With facile work-up, the novel catalyst can be readily recovered after the reaction and reused without any loss of its catalytic activity.     

Sevelamer as an efficient and reusable heterogeneous catalyst for the Knoevenagel reaction in water

A catalyst system of Sevelamer, a phosphate-binding drug, has been prepared and used in the Knoevenagel reaction of aromatic aldehydes in water to produce substituted electrophilic alkenes. The products were obtained in excellent yields. Several novel, related catalytic systems showed promising catalytic properties for aromatic and heterocyclic aldehydes. The Sevelamer catalyst can be recovered using simple filtration and reused numerous times（up to 15 times） in the aqueous Knoevenagel reaction without any significant lowering of activity.