(E)-3-溴-2-苯基丙烯腈的合成研究

在无溶剂、无催化条件下,以铁氰化钾为环境友好氰化剂对ω-溴代苯乙酮进行选择性的羰基加成脱水反应合成(E)-3-溴-2-苯基丙烯腈。最佳投料比n(ω-溴代苯乙酮)∶n(K3[Fe(CN)6])=3∶1,反应温度为190℃,反应时间为30 min,产物收率达82%。产物经IR、元素分析、1H NMR和13C NMR分析确认。此方法具有操作简单、产率高、环境友好、无溶剂、无催化反应的特点。     

芳甲酸氰基芳甲酯的合成

芳甲酸氰基芳甲酯是重要的有机合成中间体,其现有合成方法采用剧毒氰化物为氰源来合成。 本研究以K₄[Fe(CN)₆]为绿色氰化试剂,芳酰氯为原料,采用一锅两步反应合成芳甲酸氰基芳甲酯。 通过改变第二步反应温度、反应时间、硼氢化钠和催化剂的用量获得最佳反应条件,以61.7%~80.3%的产率合成了10种芳甲酸氰基芳甲酯(2a~2j),产物结构通过傅里叶变换红外光谱仪(FTIR)、核磁共振波谱仪(NMR)分析确认。 根据实验结果,提出了可能的反应机理。 该法避免了对剧毒氰化剂的使用,具有产率高、操作简单、后处理方便等优点。     

“一锅法”无溶剂条件下碳基固体酸催化合成萘酚衍生物

无溶剂条件下,含高密度(1.96 mmol·g~(-1))-SO_3H基团的太西煤基活性炭@聚苯胺基磺化固体酸可有效催化2-萘酚、醛和胺三组分反应,并采用"一锅法"合成酰胺基烷基萘酚衍生物。考察了催化剂用量、温度及溶剂条件对产率的影响。结果如下:在无溶剂条件下,反应时间为20-80 min,反应温度为100℃,催化剂用量为1%时,产率可达76%-95%,且该催化剂重复使用4次仍保持较高活性。通过熔点,~1H NMR,~(13)C NMR分析对产物的结构进行测定和表征。同时推测该反应可能的反应机理。     

新型钯催化剂的制备及其在温和条件下对芳香醛的选择性还原

以邻苯二胺为配体，制备了一种新型的纳米钯催化剂（Pd-NPs），其结构经TEM, FT-IR, XRD, XPS, EA和ICP OES表征。常温常压下，以H₂作氢源，水为溶剂，研究了Pd-NPs对芳香醛选择性还原反应的影响，产物结构经¹H NMR和¹³C NMR确证。以苯甲醛的还原反应作为模板反应，研究了配体、催化剂用量和反应时间对苯甲醇产率的影响。结果表明：在最佳反应条件（配体为邻苯二胺，Pd-NPs用量10 mol%，反应5 h）下，苯甲醇产率达99%。     

GaCl_3催化胺与碳二亚胺的加成反应合成胍的研究

以路易斯酸Ga Cl3为催化剂,在无水、无氧、氮气保护无溶剂条件下催化胺与碳二亚胺合成胍的反应,得到一系列胍产物,研究了催化剂用量,反应温度和反应时间对催化反应的影响,研究发现Ga Cl3具有良好的催化活性,以5mol%催化剂用量,无溶剂条件下一级芳香胺与碳二亚胺反应在一小时内得到高于90%产率的胍产物,二级胺也能得到较好产率。     

无溶剂、无催化剂条件下5-[(3-吲哚基)-芳甲基]-2,2-二甲基- 1,3-二氧六环-4,6-二酮的合成

在无溶剂和催化剂条件下,由芳香醛、吲哚、丙二酸亚异丙酯的三组分缩合反应,制备了5-[(3-吲哚基)-芳甲基]-2,2-二甲基-1,3-二氧六环-4,6-二酮,产率为70%～85%,产物结构经1H NMR,IR确证.     

超声法合成3,4-二甲氧基-4'-羟基查尔酮

以3,4-二甲氧基-苯甲醛和对羟基苯乙酮为原料,无水乙醇为溶剂,HCl气体为催化剂,在超声作用下,经Claisen-Schmidt缩合反应合成了3,4-二甲氧基-4′-羟基查尔酮。 产物结构经IR和1H NMR进行了表征,在2种原料摩尔比1∶1投料比条件下,优化的合成条件为超声输出功率240 W,反应温度30 ℃,反应时间20 min,产率达到92.1%,比传统方法反应时间短、操作简便、产率高。     

乙酸酐、H2O2和1,5-二羟基萘酚一锅合成胡桃醌

由乙酸酐和H2O2在无硫酸存在下合成过氧乙酸,然后向其滴加1,5-二萘酚的甲醇溶液,在一锅内简便地合成了胡桃醌。产物用苯重结晶,其结构经HPLC、UV-Vis、FTIR、1H NMR和13C NMR测试技术进行了表征和证实。考察了原料摩尔比、反应温度和反应时间对产率的影响。最佳反应条件为:n(1,5-二萘酚)∶n(乙酸酐)∶n(H2O2)=1∶4∶8,反应温度为40~60℃,反应时间为5.5 h,产率68%。结果表明,一锅法合成不用硫酸,无需真空蒸馏纯化过氧乙酸,是合成胡桃醌的简便方法。     

Brnsted酸性离子液体催化3,4-二氢嘧啶-2-酮衍生物的合成

以Brnsted酸性离子液体3-甲基咪唑丙烷磺酸-三氟乙酸作为催化剂,无溶剂条件下由芳香醛、乙酰乙酸乙酯和尿素合成了系列3,4-二氢嘧啶-2-酮衍生物.沸水浴中反应30～40 min,产物产率在81%～94%之间.该方法具有反应时间短、收率高、催化剂可回收重复使用等优点.产物结构经1H NMR,IR确证.     

偕二酸酯的无溶剂合成

以醛和酸酐为原料,溴化锌为催化剂,无溶剂条件下高产率地合成了偕二酸酯(其中醛与苯甲酸酐的反应是首次报道)。部分产物的结构经NMR,IR和MS表征。     

Solvent-free and catalyst-free method for the synthesis of 2,4,5-triarylimidazoles under microwave irradiation

A facile procedure for the synthesis of 2,4,5-triarylimidazoles is being reported starting from benzil, aromatic aldehyde and ammonium acetate. The reactions were carried out with catalyst-free, solvent-free and under microwave irradiation conditions in high yield (80–99%) with short time (3–5 min) and environmental benign, as well as convenient operation. The structures of the compounds have been confirmed on the basis of their IR, ¹H NMR, and/or ¹³C NMR, MS, and elemental analyzer.     

Catalyst-free and solvent-free method for the synthesis of quinoxalines under microwave irradiation

A facile procedure for the synthesis.of quinoxalines is being reported starting from benzil and 1,2-diaminobenzene. Thereactions were carried out catalyst-free, solvent-free and under microwave irradiation conditions in high yield (84-98%) with short time (3-6 rain) and environmental benign, as well as convenient operation. The structures of all the compounds have been confirmed on the basis of their IR, 1H NMR, and/or 13C NMR, mass spectral data.     

Selective synthetic routes to sterically hindered unsymmetrical diaryl ketones via arylstannanes

Bulky arylstannanes and bulky aroyl chlorides are good reaction partners for the synthesis of two-, three-, and even four-ortho-substituted benzophenones, in good to excellent isolated yields (47-91%). Three simple and direct routes, with differential advantages, are proposed: (i) a catalyst-free protocol, in o-dichlorobenzene (ODCB) at 180 °C; (ii) a room temperature protocol, using AlCl(3) (0.5 equiv), in dichloromethane (DCM); and (iii) a solvent-free, indium-promoted procedure. A radical mechanism is proposed for the indium-mediated reactions.     

芳基咪唑并[4,5-f][1,10]菲咯啉的无溶剂绿色合成研究

以菲咯啉二酮、苯甲醛及其衍生物和醋酸铵为原料,采用无溶剂绿色研磨工艺,合成了芳基咪唑并菲咯啉化合物.通过对不同反应条件的筛选,得到一条高效、简便、绿色的合成芳基咪唑并菲咯啉化合物路线,不同的芳醛与菲咯啉二酮都可以较高的收率得到相应的芳基咪唑并[4,5-f][1,10]菲咯啉.     

Visible light irradiation promoted catalyst-free and solvent-free synthesis of pyrano[2,3-d]pyrimidine scaffolds at room temperature

A catalyst-free and solvent-free synthetic route for convenient one-pot synthesizing pyrano[2,3-d] pyrimidine scaffolds through Knoevenagel-Michael cyclocondensation is reported using visible light irradiation as a green promoter at room temperature based on green chemistry principles. Completing the reactions takes thoroughly less time while obtaining the products in outstanding yields. This green method includes the application of non-hazardous reaction circumstances, direct work-up without column chromatographic separation, catalyst-free, solvent-free, cost effective, simple synthesis, one-pot procedure, and high atom-economy.     

Simple and Efficient Procedure for the Synthesis of Symmetrical Bis-Schiff Bases of 5,5′-Methylenebis(2-aminothiazole) Under Solvent-Free Conditions

A simple and efficient procedure for the synthesis of symmetrical bis-Schiff bases has been described that employs a condensation reaction of symmetrical primary bis-amine of 5,5′-methylenebis(2-aminothiazole) with a series of aromatic aldehyde derivatives under solvent-free conditions at elevated temperature. The advantages of these reactions are simplicity of the reaction procedure, short reaction times, simple workup, catalyst-free conditions, and pure products in good to excellent yields. Details of the reaction conditions are discussed.     

New three-component cyclocondensation reaction: microwave-assisted one-pot synthesis of 5-unsubstituted-3,4-dihydropyrimidin-2(1H)-ones under solvent-free conditions

Sixteen 5-unsubstituted-3,4-dihydropyrimidin-2(1H)-ones have been synthesized by microwave-assisted Biginelli reactions in a short and concise manner employing ZnI₂ as a catalyst under solvent-free conditions. All products were identified by IR, NMR, elemental analysis and HRMS. The advantages of this novel protocol include the excellent yield, operational simplicity, short time and the avoidance of the use of organic solvents and expensive catalysts.     

脱氧胆酸裂口分子的微波合成

以固体K2CO3为载体,在微波辐射无溶剂条件下,脱氧胆酸甲酯与芳酰氯反应合成了9个新的脱氧胆酸裂口分子人工受体,其结构经1H NMR,IR,MS及元素分析表征.     

An improved protocol for Petasis reaction of 2-pyridinecarbaldehydes

A highly efficient and improved method has been developed for Petasis reactions of various 2-pyridinecarbaldehydes with secondary amines and boronic acids under catalyst-free conditions. The desired products are obtained in up to 96% yield in refluxed acetonitrile.     

Epoxidation of vinyl cyanides by calcium hypochlorite under catalyst- and solvent-free conditions

In this paper, epoxidation of a wide range of alkenes by calcium hypochlorite (Ca(OCl)₂) was investigated under catalyst- and solvent-free conditions. It was noticed that the highest yield was achieved with crushing, when the reaction was between vinyl cyanides and Ca(OCl)₂. The structure of the synthesized epoxides was confirmed by IR, ¹H and ¹³C NMR and elemental analysis. Short reaction times, the use of a simple experimental procedure, and reducing of energy consumption are other important advantages of our work that could be mentioned too.