Efficient and Green Microwave-Assisted Multicomponent Biginelli Reaction for the Synthesis of Dihydropyrimidinones Catalyzed by Heteropolyanion-Based Ionic Liquids Under Solvent-Free Conditions

An efficient and green route for the synthesis of dihydropyrimidinones via microwave-assisted Biginelli reaction catalyzed by 3 mol% of heteropolyanion-based ionic liquids under solvent-free conditions has been reported. The practical reaction was found to be compatible with different structurally diverse substrates. Good to excellent yields, short reaction times, and operational simplicity are the main highlights of this protocol. Moreover, the heteropolyanion-based ionic liquids were easily reusable for this Biginelli reaction.     

甲酸催化的室温无溶剂条件下利用Paal-Knorr反应合成吡咯衍生物的方法

以甲酸为催化剂, 无需使用任何溶剂, 在室温条件下, 多种伯胺(包括脂肪胺、芳香胺)与2,5-己二酮发生Paal-Knorr缩合反应, 生成相应的吡咯衍生物. 该方法反应条件温和、操作简便、反应时间比较短、产物易于分离、收率高、环境友好.     

Highly Efficient Synthesis of Trioxopyrimidine-Based Chalconoids Under Solvent-Free Conditions

Straightforward procedures for the fast and efficient synthesis of differently substituted barbituric acid–based chalconoids under solvent-free conditions were developed.     

无溶剂无催化剂条件下二硫代氨基甲酸酯衍生物的合成研究

主要研究了二硫代氨基甲酸酯衍生物的合成,将脂肪胺、CS2与α,β-不饱和羰基化合物或卤代烃在无溶剂无催化剂室温条件下,"一锅法"进行了Michael-type的加成反应,合成了二硫代氨基甲酸酯衍生物.该方法产率高,操作简单,是一种原子经济的合成方法,并可大规模地用于制药及农药方面.     

氧化锌催化淀粉/乳酸接枝共聚物的制备与表征

以氧化锌为催化剂,采用原位聚合法制备了淀粉/乳酸接枝共聚物。由FT-IR、1H NMR、XRD和SEM对接枝产物进行了表征,且讨论了反应温度、淀粉与乳酸质量比、催化剂用量和反应时间对淀粉接枝率的影响,结果表明,当反应温度为95℃,淀粉与乳酸质量比为1∶5,催化剂用量为乳酸质量的1.0%,反应时间11 h时,产物的接枝率可达到14.20%。     

Efficient Synthesis of Ferrocenylcyclohexenone Under Solvent-Free Conditions

An efficient method for the synthesis of a series of ferrocenylcyclohexenones via tandem Michael–aldol reaction of ferrocenyl-substituted chalcones with dibenzyl ketone under solvent-free conditions is described. It was found that the factors including the electronic nature of chalcone, basicity of the base, reaction time, and temperature have effects on the formation of the ferrocenylcyclohexenones.     

Green One-Pot Synthesis of 2H-Pyrans Under Solvent-Free Conditions Catalyzed by Ethylenediammonium Diacetate

Ethylenediammonium diacetate readily catalyzes the Knoevenagel-type condensation between 1,3-dicarbonyl substrates and α,β-unsaturated aldehydes at room temperature under solvent-free conditions. This rapid, efficient, and convenient one-pot approach to the synthesis of 2H-pyrans stands as a significant advance over previously reported protocols. This environmentally friendly methodology has been successfully applied to the synthesis of biologically active natural products of interest zanthosimuline, N-methylflindersine, and ferprenin.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications ^® to view the free supplemental file.     

纳米氧化锌的合成与表征

纳米氧化锌的合成与表征何勇宁，沈孝良，马礼敦（复旦大学分析测试中心上海２００４３３）关键词纳米材料，氧化锌，合成，表征制备纳米材料的方法很多，如蒸发冷凝法、化学气相沉积法、溶胶－凝胶法、超临界法、水热法及各种热分解法等。Ｌｉｕ等［２］用超声雾化热分解...     

An Efficient and Solvent-Free Reaction for Synthesis of Bis（indol-3-yl）methanes Catalyzed by Sulfamic Acid

SA （sulfamic acid） catalyzes the reaction of indole with aldehyde and ketone to afford bis（indol-3-yl）methanes in good to excellent yields under solvent-free condition at ambient temperature.     

EDTA滴定法测定含锌物料中氧化锌

采用氯化铵-氨水体系溶解试样,干过滤后,向移取的滤液中加入氯化钡和硫酸共沉淀铅离子,过滤分离硫酸铅沉淀,向滤液中加人抗坏血酸、氟化钾、硫代硫酸钠等掩蔽剂掩蔽少量干扰元素。在pH=5~6的乙酸-乙酸钠缓冲溶液中,以二甲酚橙为指示剂,用EDTA标准滴定溶液滴定测得结果为氧化锌、水溶性锌和镉合量,扣除由原子吸收光谱法测得的水溶性锌量和镉量,即为氧化锌量。对总氨浓度、氯化铵-氨水浓度比、溶液加入量、搅拌时间、共存离子干扰、精密度等进行了实验,建立了EDTA滴定法测定含锌物料中氧化锌物相的分析方法。实验证明,氧化锌含量在24%~83%时,方法精密度(RSD)为0.25%~0.54%,加标回收率在99%~104%,完全满足含锌物料中氧化锌的测定要求。     

Mechanochemical Pretreatment for Efficient Solvent-Free Synthesis of SSZ-13 Zeolite

The economical and environmentally benign synthesis of SSZ-13 zeolite was possible due to the mechanochemical activation of dry reagents by planetary mill. Contrary to manual grinding in a mortar, the proposed automatized approach is scalable and reproducible. This solvent-free process provided a huge gain in product/gel ratios, significantly minimized reaction space and organic structure-directing agent use, and allowed for the elimination of agitation. Obtained materials were comparable to the product of “classical” syntheses. The use of different silica sources resulted in SSZ-13 zeolites with various characteristics: different Si/Al ratio and crystal size.     

A Rapid and Efficient Multicomponent Synthesis of Bi-Quinolines Under Solvent-Free Conditions

An efficient synthesis of substituted condensed quinolino-quinolines has been achieved in a one-pot reaction from 2-hydroxy/mercapto/seleno-4-methylquinoline and 2-mercapto/seleno-3-formyl quinolines using anhydrous ammonium hydroxide as the reductant by microwave irradiation under solvent-free conditions.     

Simple,Efficient, and Green Procedure for the Knoevenagel Condensation Catalyzed by Ethylenediammonium Diacetate Under Solvent-Free Conditions

A simple, efficient, and green procedure for Knoevenagel condensation of aromatic aldehydes with malononitrile and ethyl cyanoacetate catalyzed by ethylenediammonium diacetate under solvent-free conditions at room temperature is reported. This method gives remarkable advantages such as a simple procedure, mild conditions, fast (1–45 min) reactions, and excellent yields. Additionally, the catalyst can be reused for at least five runs without significant decrease of the yields.      

Zn取代的磷钨酸季铵盐无溶剂氧化苯甲醇合成苯甲醛

合成了一系列过渡金属Zn取代的Keggin型磷钨杂多酸的季铵盐,采用傅里叶变换红外光谱(FTIR)、X射线衍射(XRD)等方法表征了杂多化合物的结构.并将其用于苯甲醇无溶剂氧化合成苯甲醛的反应,考察了催化剂种类、反应条件对苯甲醇氧化的影响.实验结果表明,在无任何溶剂的情况下,Zn取代的Keggin型磷钨四丁基铵盐具有最佳的催化活性,反应时间仅为30 min,苯甲醇的转化率可以达到95.6%,苯甲醛的选择性达到了96.4%.在对杂多酸季铵盐结构的研究基础上,对可能的反应机理进行了初步探讨.     

Knoevenagel Condensation Catalyzed by Sodium Silicate Under Solvent-Free Conditions

Abstract

Sodium silicate pentahydrate has been utilized as an efficient catalyst for the Knoevenagel condensation of aromatic aldehydes with active methylene compounds to afford substituted olefins in yields of 80.6%～98.9% under solvent-free conditions at room temperature within a short time. The advantages of this procedure are mild reaction conditions, excellent yields, cleaner reaction profiles, and operational simplicity.

GRAPHICAL ABSTRACT      

Highly Regioselective Ring Opening of Epoxides with Thiols Catalyzed by SbCl3 Under Solvent-Free Conditions

The ring-opening reaction of epoxides with thiols by SbCl ₃ supported on Kieselguhr under solvent-free conditions, afforded high yields of β-hydroxy sulfides. Nucleophilic attack of the thiols occurs regioselectively at the less hindered side of the epoxides.     

花状氧化锌纳米晶的制备及其电化学传感研究

本文以丙三醇为反应溶剂,在氧氧化钾体系中制备了两种花状氧化锌纳米晶.讨论了不同实验条件对氧化锌纳米晶形成影响,通过改变氢氧化钾浓度、反应温度和体系中水含量等条件来调节材料形貌.探讨了花状氧化锌纳米晶可能的形成过程.用X射线粉末衍射、扫描电子显微镜、紫外可见光谱等分析技术对制备的氧化锌纳米晶进行了表征.结果表明两种花状纳...     

硫酸锌催化合成草酸二异戊酯

酯化;催化活性;硫酸锌催化合成草酸二异戊酯     

Controllable Synthesis and Optical Properties of Connected Zinc Oxide Nanoparticles

Connected zinc oxide (ZnO) nanoparticles are successfully synthesized by a simple solution‐based chemical route that uses evaporation and concentration technology. The influences of processing parameters, especially the evaporation and concentration time on the size and morphology of the nanoparticles, have been investigated by transmission electron microscopy (TEM) and high‐resolution TEM (HRTEM). The structure and optical properties are systematically characterized by X‐ray diffraction (XRD), UV/Vis spectrophotometery, and fluorescence spectroscopy (FL). It is found that the average diameter and morphology are strongly affected by the evaporation and concentration time. Additionally, the formation mechanism of the nanoparticles is also discussed. The studies revealed that the evaporation and concentration are important aggregation or nucleation processes for ZnO growth, which leads to the macro‐differences in morphology. These results provide some insight into the growth mechanism of ZnO nanostructures. The synthetic strategy developed in this study may also be extended to the preparation of other nanomaterials and promising applications in various fields of nanotechnology.     

Efficient and Novel Synthesis of Benzoxazole Derivatives in the Presence of Zinc Dust Under Solvent-Free Conditions

A mild and efficient method has been developed for the synthesis of 2-cyclic amine-substituted benzoxazole derivatives using zinc dust under microwave irradiation in the absence of solvent is described. A comparative study was performed under conventional and microwave heating conditions. Zinc dust can be reused several times after reactivation. The significant feature of this method is the isolation of the pure product by simple workup in a short reaction time with high purity.