Noble Metal Nanoparticles Incorporated in Mesoporous Hosts

Noble metal nanoparticle containing [Me] _x -MCM-41 were synthesized using surfactant stabilised palladium, iridium and rhodium nanoparticles in the synthesis gel. The materials were characterised with XRD, ICP AES, TA, TEM and nitrogen sorption, which showed that the nanoparticles were present inside the pores of MCM-41. The [Me] _x -MCM-41 were found to be active and selective catalysts in the hydrogenation of cyclic olefins such as cyclohexene, cyclooctene, cyclododecene and norbornene.     

A New Indole Synthesis Promoted by Metal Triflates

A new synthesis of 4- and 7-carbon-substituted indoles is described. The overall sequence involves the addition of a nitrile oxide to 1 carboethoxy-2-(or 3-) allylpyrrole, hydrogenation of the intermediate isoxazoline to β-hydroxy ketone and cyclization of the ketol using magnesium or zinc triflate to the substituted indole. This new indole-forming strategy can also accommodate the introduction of oxygen functionality into the indole 6-position. Possible mechanistic aspects of the reaction are detailed.     

离子液体在精细化学品合成中的应用

概述了近几年离子液体在医药、食品添加剂、农药等精细化学品合成中的应用。离子液体表现出的主要优势在于:它无毒无害,对环境友好,可以替代有毒、腐蚀性的溶剂或催化剂;反应速度快,条件温和,收率高,选择性好,特别适合高纯产物的合成;中间体无需分离,多步合成操作过程可以连续进行,简化了合成工艺;产物易分离,离子液体/催化剂可循环使用;离子液相有机合成具有比固相合成担载量高的优势,适用于药物的组合化学合成中。设计合成高效、多功能、价廉、易降解的离子液体,将加速离子液体由基础研究到中试研究和工业应用的步伐,使之在精细化学品合成中带来更大的经济、环境效益。引文36篇。     

绿色化工技术在精细化工中的应用分析

随着可持续发展的趋势愈来愈近,化工方面的科技发展应用开始追求更加经济、绿色的发展目标。产业的技术性变革使绿色化工技术成为主流,社会、经济和生态等方面的相互协调,和谐发展的同时,对化工的精细、精准要求愈来愈高,日渐发展成为领域研究的主流。就绿色化工技术在精细化工中应用的现状、发展以及今后的前景进行研究、介绍,为绿色化工更深入的研究、实践提供借鉴材料。     

新型催化剂在精细化学品合成中的应用

简述了新型催化剂在表面活性剂、除草剂、除虫剂、食品添加剂、医药、橡胶材料、增塑剂、香料、植物生长调节剂等精细化学品合成中的应用。并重点说明了非贵金属催化剂和对环境友好催化剂——固体超强酸的重要性和必要性。     

Base Catalysis in the Synthesis of Fine Chemicals

The catalytic properties of hydrotalcites are investigated for reactions of aldolisation, Meerwein–Ponndorf–Verley hydrogenations, epoxidations and oxidations, Michael and Wadsworth–Emmons additions. Excellent yields have been reported using mild conditions and catalysts which can be easily separated from the reaction medium and could be regenerated. The catalytic properties are controlled by the activation of the solid, and traces of chlorine appear to be deleterious. In many cases rehydration increases activity dramatically. Solid bases give a very specific catalysis for instance with Michael or Wadsworth–Emmons reactions of aldolisable compounds due to the exclusion of carbonyls from the surface by the other reactant.     

浅谈精细化工品合成的化学应用

研究精细化工品合成的意义在于明确精细化工的相关概念及原理,找到其在化学中的应用途径,以推动相关领域发展进步。针对精细化工的概念及分类进行了简单的介绍分析,然后从离子液体、分离技术、催化技术等方面深入分析了精细化工品合成的化学应用,以期可以给予业界人士一定参考作用。     

Recent Advances in Metal Nanoparticles Stabilization into Nanopores of Montmorillonite and Their Catalytic Applications for Fine Chemicals Synthesis

Metal nanoparticles supported montmorillonite with innovative characteristics has led to a new generation of heterogeneous “nanocatalyst.” Such catalysts are superior to the conventional catalysts because of several factors like: higher surface area; higher activity; higher selectivity and longer life and thus, developing a newer type of sustainable environmentally friendly catalysts. Metal clay supported nanocatalysts may find a wide range of applications in the area of fine and bulk chemical industries, pharmaceuticals, fuel cell, petroleum refineries, environmental catalysis, and many other fields. This article summarizes the recent advances in the synthesis and characterization of metal nanoparticles supported on modified montmorillonite and their catalytic applications for fine chemicals synthesis.     

精细有机化学品合成中醇的催化氧化新进展

综述了使用洁净氧化剂（氧气、过氧化氢）,液相催化氧化有机醇的新进展。并对均相及多相催化剂体系中催化氧化有机醇在精细化学品合成中的应用进行了比较。     

有机合成中的三氟甲磺酸金属盐催化剂

三氟甲磺酸金属盐催化剂有极强的热力学及化学稳定性,在温和的反应条件下具有活性高、选择性好、收率高、低毒性和可循环使用等特点而广受关注,能够催化亲电取代、亲核取代和加成等多种反应,而且可以用于全水相高效催化。简要总结了三氟甲磺酸金属盐在有机合成中的应用情况,包括傅克反应、缩醛反应、氢烷氧化与氢胺化反应、烯丙基化反应、成环开环反应、氧化与还原反应、重排反应等多种合成领域。     

杂多化合物催化剂在精细化工合成中的应用

本文综术了杂多化合物作为酸催化剂，催化烷基化和去烷基化反应、缩聚反应、水合和失水、酯化和醚化反应；以及作为氧化催化剂，在烯烃、芳烃、酚的氧化和环氧化反应中的应用。表面杂多化合物作为催化剂在合成精细化学中有广泛的应用价值。     

Synthesis and Characterization of Dendrimer-Templated Mesoporous Oxidation Catalysts

We report here the use of 4th and 5th generation dendrimers poly(propylene)imine (CU-D32 and CU-D64) as templating agents for the synthesis of mesoporous titanosilicate and vanadosilicate oxidation catalysts via solgel techniques. The physical properties of these mesoporous materials were characterized by TGA, BET, PXD and SEM/EDX analyses and these showed that the transition metals are evenly distributed throughout these silicates, which have interconnected spherical pores (approx. 12Å in diameter) and high surface areas of about 650m²g^–1. Kinetic studies showed that all transition metal-doped catalysts were highly selective at oxidizing cyclohexene to the corresponding epoxide. Additionally, CU-D64-templated catalysts were more catalytically active for cyclohexene epoxidation than CU-D32-templated catalysts as a result of differences in pore size. All CU-D64-templated catalysts exhibited epoxidation catalytic activity comparable to that of titanium doped MCM-41 materials.     

晶态介孔金属氧化物的合成研究进展

晶态介孔金属氧化物与相应的无定形材料相比具有更加优异的催化、光学、电学、磁学和力学等性能,具有较宽的应用范围,是近年来介孔材料合成的热点。本文主要对晶态介孔金属氧化物的制备方法,包括非晶晶化法、蒸发诱导自组装法和硬模板法进行了介绍,并对这些方法的优缺点进行了比较。     

Applications of Amine-functionalized Mesoporous Silica in Fine Chemical Synthesis

SBA-15 silica containing homogeneously distributed amine-functional groups and of fiber or platelet morphology was prepared through a modified co-condensation method using P123 copolymer as template under acidic condition. Synthetic factors which led to well-ordered mesoporous materials with high loadings of various amine groups were discussed. The resultant mesoporous materials were efficient base catalysts in Knoevenagel and Claisen–Schmidt addition reactions. The activities over SBA-15 materials with different amino-functional groups are compared. Moreover, the advantage of ordered large mesopores of SBA-15 in catalyzing liquid phase reactions was demonstrated, and the reaction rate could be further increased when SBA-15 was with platelet morphology and short mesochannels.     

Chiral Synthesis on Catalysts Immobilized in Microporous and Mesoporous Materials

Abstract

This paper reviews the recent progress made in the asymmetric synthesis on chiral catalysts in porous materials and discusses the effects of surface and pores on enantioselectivity (confinement effect). This paper also summarizes various approaches of immobilization of the chiral catalysts onto surfaces and into pores of solid inorganic supports such as microporous and mesoporous materials. The most important reactions surveyed for the chiral synthesis in porous materials include epoxidation, hydrogenation, hydroformylation, Aldol and Diels‐Alder reactions, etc. The confinement effect originated from the surfaces and the pores turns out to be a general phenomenon, which may make the enantioselectivity increase (positive effect) or decrease (negative effect). The confinement effect becomes more pronounced particularly when the bonding between the catalyst and the surface is more rigid and the pore size is tuned to a suitable range. It is proposed that the confinement in chiral synthesis is essentially a consequence of subtle change in transition states induced by weak interaction in pores or on surfaces. It is also anticipated that the enantioselectivity could be improved by tuning the confinement effect based on the molecular designing of the pore/surface and the immobilized catalysts according to the requirements of chiral reactions.     

Chiral Synthesis on Catalysts Immobilized in Microporous and Mesoporous Materials

This paper reviews the recent progress made in the asymmetric synthesis on chiral catalysts in porous materials and discusses the effects of surface and pores on enantioselectivity (confinement effect). This paper also summarizes various approaches of immobilization of the chiral catalysts onto surfaces and into pores of solid inorganic supports such as microporous and mesoporous materials. The most important reactions surveyed for the chiral synthesis in porous materials include epoxidation, hydrogenation, hydroformylation, Aldol and Diels-Alder reactions, etc. The confinement effect originated from the surfaces and the pores turns out to be a general phenomenon, which may make the enantioselectivity increase (positive effect) or decrease (negative effect). The confinement effect becomes more pronounced particularly when the bonding between the catalyst and the surface is more rigid and the pore size is tuned to a suitable range. It is proposed that the confinement in chiral synthesis is essentially a consequence of subtle change in transition states induced by weak interaction in pores or on surfaces. It is also anticipated that the enantioselectivity could be improved by tuning the confinement effect based on the molecular designing of the pore/surface and the immobilized catalysts according to the requirements of chiral reactions.     

用一氧化碳合成含氮精细化学品

本文介绍了含氮化学品一种新的催化合成方法 ,以硒为催化剂 ,一氧化碳为羰基化试剂 ,通过氧化还原羰基化可一步合成非对称脲类化合物、含氮杂环脲类化合物、环脲类化合物及氨基甲酸酯类化合物。在此新反应体系中 ,催化剂呈现反应过程相转移催化特性 ,产物易分离 ,催化剂可回收循环利用。     

介孔碳负载Pt催化剂用于抗氧剂7PPD的合成

以纳米氧化锌为模板剂,酚醛树脂为碳源,采用硬模板法制备了介孔碳(MC),并以其为载体制备了Pt/MC催化剂,同时,以商品化活性炭(AC)为载体制备了Pt/AC催化剂。对制备的样品进行BET、SEM、ICP和TEM表征。结果表明,氧化锌模板剂可有效调控介孔碳的比表面积和孔结构,Pt/MC催化剂和Pt/AC催化剂的Pt负载量(质量分数,下同)均为2.8%左右,活性金属粒径均为1.8nm左右。将制备的Pt/MC催化剂用于抗氧剂N-(1,4-二甲基戊基)-N'-苯基对苯二胺(7PPD)的合成,与普通Pt/AC催化剂相比,4-氨基二苯胺(p-ADPA)的转化率由97.5%提高至100%,7PPD选择性由94.2%提高至99.5%,催化剂的稳定性明显提高。CO化学吸附、ICP、N_2低温物理吸脱附表征结果表明,催化剂载体的孔结构是影响催化剂稳定性的重要因素。当平均孔径较小时,7PPD等较大尺寸的分子容易堵塞孔道;当平均孔径较大时,孔壁较薄,催化剂使用过程中容易磨损,导致活性组分流失。     

洗油精细加工现状与绿色分离过程开发

煤焦油洗油中分离产物在农药、医药、染料、加工助剂及工程塑料等领域有着广泛的应用。目前分离洗油中α-甲基萘、β-甲基萘、喹啉、联苯、吲哚、苊及芴等普遍采用精馏重结晶方法,该方法耗能大、污染大,因此研究探讨洗油加工中的绿色分离过程是十分有必要的。绿色分离过程的主要绿色分离方法有反应精馏、绿色溶剂流体萃取及膜过程。开发绿色分离工艺对于洗油深加工方面具有一定的科研价值和工业前景。