H6P2W18O62-18H2O,a Green and Reusable Catalyst for the Three-Component,One-Pot Synthesis of 4,6-Diarylpyrimidin-2(1H)-ones Under Solvent-Free Conditions

Three-component, one-pot synthesis of 4,6-diarylpyrimidin-2(1H)-ones and 9-phenyl-8-oxa-10,12-diaza-tricyclo[7.3.1.0^2,7]trideca-2(7),3,5-trien-11-one by condensing acetophenone derivatives, aldehydes, and urea in the presence of trimethylsilyl chloride using a catalytic amount of H₆P₂W₁₈O₆₂-18H₂O under solvent-free conditions is reported.     

ZrOCl2·8H2O catalyzed solvent-free synthesis of isobenzofuran-1（3H）-ones

ZrOCl₂·8H₂O catalyzed environmentally benign synthesis of isobenzofuran-1（3H）-ones are described.ZrOCl₂·8H₂O appeared to be an excellent catalyst for the condensation and reactions.Reaction of phthalaldehydic acid（2-carboxybenzaldehyde） with methylaryl and cyclic ketones was initiated by condensation and occurred in one step providing excellent yields（90-98%）.     

An Efficient Procedure for the Synthesis of Benzoxazole and Benzothiazole Derivatives Using a H2O2/SiO2-FeCl3 System

A series of benzoxazole and benzothiazoles was readily prepared from the reaction of ortho-aminophenol/ortho-aminothiophenol and aldehydes using solid silica supported ferric chloride (SiO₂-FeCl₃) as catalyst followed by oxidation with H₂O₂ under ambient conditions. Some of advantages of this method are a simple and convenient procedure, easy purification, and shorter reaction times.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Facile Preparation of Indolyl-2/3-methylsulfoxides Using HF/H2O2

A variety of indolyl-2/3-methylsulfides tethered with sensitive functionalities were oxidized to the corresponding sulfoxides using a hitherto unexplored HF/H₂O₂ system.     

一水硫酸氢钠无溶剂催化合成4-甲基香豆素

NaHSO4•H2O(摩尔分数为0.1)催化下, 取代酚与乙酰乙酸乙酯(物质的量比1∶1.2)在无溶剂条件下, 通过Pechmann缩合反应, 合成了9个4-甲基香豆素衍生物, 反应时间3～5 h, 产率23%～91%, 反应条件温和、操作简便有效. 研究结果表明, 当苯酚环上取代基为一个羟基或氨基能显著加速反应, 提高产率, 苯环上更多的取代基则对反应没有促进作用; 当苯酚环上取代基为吸电子基团时, 则不发生反应或者产率很低.     

Gram-Scale Synthesis of an Ultrastable Microporous Metal-Organic Framework for Efficient Adsorptive Separation of C2H2/CO2 and C2H2/CH4

A highly water and thermally stable metal-organic framework (MOF) Zn₂(Pydc)(Ata)₂ (1, H₂Pydc = 3,5-pyridinedicarboxylic acid; HAta = 3-amino-1,2,4-triazole) was synthesized on a large scale using inexpensive commercially available ligands for efficient separation of C₂H₂ from CH₄ and CO₂. Compound 1 could take up 47.2 mL/g of C₂H₂ under ambient conditions but only 33.0 mL/g of CO₂ and 19.1 mL/g of CH₄. The calculated ideal absorbed solution theory (IAST) selectivities for equimolar C₂H₂/CO₂ and C₂H₂/CH₄ were 5.1 and 21.5, respectively, comparable to those many popular MOFs. The Q_st values for C₂H₂, CO₂, and CH₄ at a near-zero loading in 1 were 43.1, 32.1, and 22.5 kJ mol⁻¹, respectively. The practical separation performance for C₂H₂/CO₂ mixtures was further confirmed by column breakthrough experiments.     

Trimethylsilylation of Alcohols and Phenols,and Direct Acetylation of Silyl Ethers Catalyzed by Fe(ClO4)3.6H2O

In this article, a mild and efficient protocol for the trimethylsilylation of various aliphatic and benzylic alcohols and phenols with trimethylsilyl chloride using a catalytic amount of ferric perchlorate at room temperature and relatively short reaction times in good to excellent yields is reported. Direct acetylation of trimethylsilyl ethers catalyzed with Fe(ClO ₄ ) ₃ .6H ₂ O(0.02 mmol)/Fe(ClO ₄ ) ₃ SiO ₂ (0.2 g) using acetic anhydride at ambient temperature is also reported.     

An Efficient Synthesis of New 3,4-Dihydropyrimidin- 2(1H)-ones Incorporating a Phenyl Moiety at C-5 and C-6 Catalyzed by TMSCl and Co(OAc)2.4H2O

New 3,4-dihydropyrimidin-2-ones having a phenyl moiety at C-5 and C-6 have been prepared by a microwave-assisted Biginelli–like reaction by a three-component, one-pot condensation of an aromatic aldehyde, deoxybenzoin and urea, or thiourea using TMSCl and Co(OAc) ₂ .4H ₂ O as an efficient Lewis acid catalyst.     

新型纳米多孔SiO2气凝胶微球材料的制备

A new type of nanoporous SiO₂ aerogel microsphere materials were synthesized by using SiO₂ sols as raw materials in the W/O emulsion formed by the emulsification of Tween-85 and Span-80. The obtained wet gel microspheres were aged by a successive solvent exchanging of alcohol, tetraethylorthosilicate (TEOS)/ethanol solution and ethanol at 60 ℃, and then were dried at ambient pressure to produce SiO₂ aerogel microspheres. The resultant SiO₂ aerogel microspheres were characterized by SEM, TEM and nitrogen adsorption-desorption. The results show that the prepared SiO₂ aerogel microspheres are nanoporous materials with coherent network nanoporous structure consisting of SiO₂ nanoparticles with an average diameter of about 10 nm. The apparent density of a typical sample is 0.4 g·cm^-3, while the specific surface area is 386 m²·g^-1, and the average pore size is 18 nm with the porosity of 84%. Various SiO₂ aerogel microspheres with the apparent particle sizes of 10～200 μm can be synthesized by controlling the stirring speed at 600～2 000 r·min^-1, the volume ratio of water/oil from 0.10 to 0.30, and the weight ratio of Tween-85/Span-80 less than 0.40.     

Cu2O/g-C3N4催化合成吲哚-2-羧酸酯

我们通过原位还原的方法将吸附在g-C3N4表面上Cu2+还原,制备出Cu2O/g-C3N4复合材料,并利用XRD、SEM、FT-IR、XPS等分析手段表征Cu2O/g-C3N4.表征结果显示:Cu元素主要以Cu2O的形式吸附在g-C3N4载体上.另外,还考察了Cu2O/g-C3 N4在“一锅法”合成吲哚-2-甲酸乙酯的反应中的催化性能.结果表明:即使在较低的催化担载量和温和的反应条件下,Cu2O/g-C3 N4仍能表现出良好的催化性能并获得44.1％的收率.     

TiO2/LaFeO3微纳米纤维的可控制备及光催化性能简

利用静电纺丝技术及水热合成法制备了TiO2/LaFeO3异质结构. 采用场发射扫描电子显微镜(FE-SEM),X射线衍射(XRD),傅里叶变换红外(FTIR)光谱和紫外-可见漫反射光谱(UV-Vis)等手段对TiO2/LaFeO3微纳米纤维的结构和表面形态进行表征. 通过亚甲基蓝(MB)光降解反应研究了其光催化性能. 结果表明,不完全碳化TiO2纤维表面的缺陷位点是LaFeO3纳米粒子的有利生长点. TiO2/LaFeO3异质结材料的带隙明显窄于TiO2,光催化活性得到提高;经140 min紫外光照射后,TiO2/LaFeO3异质结催化剂对MB的降解率为65.34%,分析和探讨了其光催化机理.     

新型2-(2'-取代亚肼基)-1,3-二硫杂环戊烷衍生物的合成和菌活性研究

通过结构改造并结合活性基团的拼接合成了11个未见文献报道的新型2-(2'-取代亚肼基)-1,3-二硫杂环戊烷类化合物,所有的目标物的结构都经HNMR,MS,IR和元素分析证实,选择了其中5个化合物对7种细菌进行了抑菌活性1测试,并与市售农药20%三环唑、70%威尔达甲托的抑菌活性进行对比,发现它们比市售农药有更为广泛的杀菌谱,对照农药只对金黄色葡萄球菌有良好的抑菌作用而这些化合物则对所选择的七个菌种均有良好的抑菌作用.其中化合物2-(对氟苯氧乙酰亚肼基)-1,3-二硫杂环戊烷(4c)的杀菌谱很广,它对金色葡萄球菌、大肠杆菌、白色念珠菌的抑杀活性都很好.     

Synthesis and thermal investigation of Na2Cd(SO4)2·2H2O

The synthesis and thermal decomposition of Na₂(SO₄)₂·2H₂O in both air and nitrogen are described. The synthesis was performed by two different procedures, but in both cases the same product was obtained, corresponding to the general formula given above. The crystals obtained were investigated by methods of X-ray powder diffraction, and chemical and thermal analysis. The differences in thermal decomposition in air and nitrogen are discussed.     

Chemoselective Deprotection of Thioacetals/Thioketals Using HIO3 in the Presence of Wet SiO2 Under Mild Solvent-Free Conditions

Abstract

HIO ₃ in the presence of wet SiO ₂ is highly efficient and a mild reagent for selective deprotection of a variety of thioacetals/thioketals to the corresponding parent carbonyl compounds at room temperature and under solvent-free conditions.     

Ecofriendly Solventless Synthesis and Reduction Reaction of Some Triazole Compounds and Evaluation of Their Antimicrobial Activity

A number of triazole-3-one compounds have been synthesized, and reduction of the carbonyl group in the molecule has been carried out to give a corresponding hydroxyl group that possesses asymmetric carbon atom in good yields and short reaction times. It is ecofriendly because it is produced by straightforward microwave irradiation in the absence of solvent. All newly synthesized compounds were also screened for their antimicrobial activities. The antimicrobial activity study revealed that 2d, 2i, 3c, and 3g–j showed good activity against a variety of microorganisms.

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

A green synthesis of 3,4-dihydropyrimidin-2-ones and 1,5-benzodiazepines catalyzed by Sn(HPO4)2.H2O nanodisks under solvent-free condition at room temperature

Abstract

Heterogeneous Tin (IV) hydrogen phosphate nanodisks [Sn(HPO4)2.H2O] efficiently catalyzed the one-pot three component condensation of aromatic aldehydes, β-ketoesters and urea to produce 3,4–dihydropyrimidin-2-ones under solvent-free conditions at room temperature. Also, the catalyst is equally applicable for the preparation of 1,5–benzodiazepines under the same reaction conditions. The optimum load of the catalyst required is 10 mole% and reusable. Hence, the process is green.

Solvent-Free Synthesis of Nitrilotriacetamide and Diketopiperazines from Nitrilotriacetic Acid under Microwave Irradiation and Their Antimicrobial Activity

Efficient synthesis of dioxopiperazines‐diketopiperzines (DKPs)‐ and amide from nitrilotriacetic acid (NTA) using microwave irradiation and classical heating were described. All compounds were characterized using ¹H NMR, ¹³C NMR and elemental analysis. Antimicrobial effects of these compounds are also investigated. All tested compounds showed moderate antimicrobial activity.     

KF/Al2O3 as an Efficient,Green, and Reusable Catalytic System for the Solvent-Free Synthesis of N-Alkyl Derivatives of Sulfonamides via Michael Reactions

KF/Al ₂ O ₃ efficiently catalyzes the microwave-assisted Michael addition of sulfonamides to α,β-unsaturated esters under solvent-free conditions to afford N-alkyl derivatives of sulfonamides as biologically interesting compounds in high yields and in short reaction times. In this reaction, N,N-dialkylsulfonamides are also produced, but in very low yields.