无溶剂条件下DBU催化Knoevenagel缩合反应的研究

建立了一种以有机碱1,8-二氮杂二环（5.4.0）十一稀-7（DBU）为催化剂的无溶剂反应条件的高效、快速和简便的Knoevenagel缩合芳香醛与活泼亚甲基化合物的反应体系。此反应体系能够在室温条件下顺利进行,而且在较短的反应时间内完成反应并得到大于85%的产物收率,且后处理非常简单。最后,讨论了可能的反应机理。     

无溶剂条件下的有机反应——催化条件下醇与酸酐的反应

无溶剂条件下，无水ＣｏＣｌ２或干燥的强酸性阳离子交换树脂－ＳＯ３Ｈ催化醇和酸酐的反应，得到高产率的酯。实验证明无溶剂条件下反应简单，操作容易，反应时间短，产率高。     

异丁醛1,4—丁烯二醇缩合反应的研究

将异丁醛与1,4-丁烯二醇缩合得到产物二氧七环,对产物进行了元素分析和IR分析,初步探讨了反应物浓度、温度、酸度和反应时间对产物产率的影响。     

氯化异丁醛的合成研究

异丁醛是由丙烯经羰基合成的工业副产物,其产量在我国日益增长。异丁醛在一定条件下经氯化反应生成α-氯化异丁醛(以下简称氯化异丁醛),它是有机合成的重要化合物。自氯化异丁醛制取农药涕灭威,是一条比较先进的工艺路线。从工业副产物的综合利用上来讲,更具有重要的意义。异丁醛的气相氯化和液相氯化,国外已进     

异丁醛的利用

异丁醛是羰基合成生产丁辛醇的副产物。我国引进的几套大型丁辛醇生产装置,相继在吉林、大庆和山东齐鲁石化公司建成投产,全国每年有4～5万吨的副产异丁醛。异丁醛的综合利用是当前石油化工中一个很重要的研究课题。异丁醛的化学性质活泼,可以加工为多种精细化工产品,因而引起关注。近来,以异丁醛为原料的有机合成研究报道很多,其产品多属国内短缺产品,故异丁醛的综合利用具有较高的社会效益和经济效益。下面概括地     

异丁醛与1,4-丁烯二醇缩合反应的研究

将异丁醛与1,4-丁烯二醇缩合得到产物二氧七环,对产物进行了元素分析和IR分析.初步探讨了反应物浓度、温度、酸度和反应时间对产物产率的影响.     

室温无溶剂条件下离子液体催化的Knoevenagel缩合反应

在室温无外加溶剂条件下,甲酸乙醇铵离子液体催化一系列芳醛和活泼亚甲基化合物进行Knoevenagel缩合反应,短时间内以高产率生产相应产物。实验表明甲酸乙醇铵可以有效地催化Knoevenagel缩合反应,并可以循环使用。     

超声波无溶剂条件下对氯苯甲醛与硝基甲烷的缩合反应

在超声波作用和无溶剂条件下,对氯苯甲醛与硝基甲烷发生缩合反应得到了β-硝基烯。最佳反应条件为反应时间2h,物料配比为n(对氯苯甲醛)∶n(硝基甲烷)∶n(氢氧化钠)=1∶40∶2.5。在此最佳反应条件下,β-硝基烯产率为80%。     

异丁醛氧化制异丁酸的研究

目前,随着石油化学工业的迅猛发展,为有机玻璃生产开辟了新的原料路线,利用由丙烯羰基合成丁辛醇的付产物异丁醛氧化脱氢二步法制备甲基丙烯酸,就是一条新的、引人注目的,重要合成路线。本报告介绍由异丁醛氧化制取异丁酸的小试研究工作情况。现分述如下:     

异丁醛合成的研究进展

概述了异丁醛的性质和用途,分析了其市场供需状况,简述了异丁醛生产技术的研究现状。重点叙述了甲醇与乙醇一步法合成异丁醛的研究进展,展望了异丁醛生产的前景和甲醇乙醇一步法合成异丁醛的研究方向。     

Monodisperse Metal Nanoparticle Catalysts: Synthesis, Characterizations, and Molecular Studies Under Reaction Conditions

We aim to develop novel catalysts that exhibit high activity, selectivity and stability under real catalytic conditions. In the recent decades, the fast development of nanoscience and nanotechnology has allowed synthesis of nanoparticles with well-defined size, shape and composition using colloidal methods. Utilization of mesoporous oxide supports effectively prevents the nanoparticles from aggregating at high temperatures and high pressures. Nanoparticles of less than 2?nm sizes were found to show unique activity and selectivity during reactions, which was due to the special surface electronic structure and atomic arrangements that are present at small particle surfaces. While oxide support materials are employed to stabilize metal nanoparticles under working conditions, the supports are also known to strongly interact with the metals through encapsulation, adsorbate spillover, and charge transfer. These factors change the catalytic performance of the metal catalysts as well as the conductivity of oxides. The employment of new in situ techniques, mainly high-pressure scanning tunneling microscopy (HPSTM) and ambient-pressure X-ray photoelectron spectroscopy (APXPS) allows the determination of the surface structure and chemical states under reaction conditions. HPSTM has identified the importance of both adsorbate mobility to catalytic turnovers and the metal substrate reconstruction driven by gaseous reactants such as CO and O₂. APXPS is able to monitor both reacting species at catalyst surfaces and the oxidation state of the catalyst while it is being exposed to gases. The surface composition of bimetallic nanoparticles depends on whether the catalysts are under oxidizing or reducing conditions, which is further correlated with the catalysis by the bimetallic catalytic systems. The product selectivity in multipath reactions correlates with the size and shape of monodisperse metal nanoparticle catalysts in structure sensitive reactions.     

CO2 Hydrogenation Studies on Co and CoPt Bimetallic Nanoparticles Under Reaction Conditions Using TEM, XPS and NEXAFS

Cobalt and platinum?Ccobalt bimetallic alloy nanoparticles of uniform size distribution where prepared and supported on MCF-17 to produce a controlled and well-characterized model catalyst which was studied under reaction conditions during CO₂ hydrogenation. Near edge X-ray absorption fine structure (NEXAFS) spectroscopy was used to elucidate the oxidation state of the catalyst under reaction conditions while the effect of reducing H₂ gas on the composition and structure of the bimetallic PtCo nanoparticles was measured using ambient pressure X-ray photoelectron spectroscopy (AP-XPS) and environmental transmission electron microscopy (ETEM). NEXAFS indicates that Pt aids the reduction of Co to its metallic state under relevant reaction conditions, while AP-XPS and ETEM indicate that Pt is enriched at the surface by exchange with subsurface layers which become Pt deficient??in agreement with the ??Pt-like?? selectivity seen during catalytic testing of these materials.     

Studies on Methylation of Anomeric Hydroxyl Groups Under Phase-Transfer Catalysed Conditions

Reaction derivatives of monosaccharides possessing a free anomeric hydroxyl group with methyl sulfate under phase-transfer catalysed conditions is described. Under phase-transfer conditions, which permit equilibrium control, the proportions of α- to β-glycosides are determined by the relative acidity of anomers. In the presence of alcohols the proportions of α to β-D-gluco- and galactopyranosides have been shifted in favor of the equatorial anomer.     

异丁醛(IBA)的合成

甲醇与乙醇或正丙醇一步合成异丁醛,甲醇与正丙醇反应,催化剂为负载钒的TiO2,反应的转化率能够达到98.9%,异丁醛的产率可达64.2%。甲醇与乙醇反应,催化剂分别为V2O5/TiO2-SiO2,CuO-ZnO/Al2O3,CuO-MnO/Al2O3时,反应的转化率分别能达98%、93.1%、93.69%,异丁醛的选择性分别能达85%、53.1%、71%。     

无溶剂无催化剂条件下合成betti碱

在无溶剂无催化剂条件下,无论是含有吸电子基团还是含有供电子基团的芳香醛都能与2-萘酚以及仲胺反应,短时间内以高产率生成氨基烷基萘酚。该方法实验操作简单,不需要使用催化剂和溶剂,减少了废物排放,降低了成本,是一种绿色合成氨基烷基萘酚的方法。