创新综合化学实验:烷基-烷基Kumada偶联反应*

为将交叉偶联反应引入本科化学实验教学中,设计了创新综合化学实验——Kumada偶联反应。该实验选取氯化亚铜作催化剂,常温下即可反应,溶剂低毒,反应时间短,产率高,符合“绿色化学”理念。该实验在无水无氧条件下进行偶联反应,再通过萃取、分液、柱层析对产物进行分离,并引入气相色谱对产物进行定性和半定量分析。通过该实验项目的学习,学生可以掌握典型的有机化合物合成、分离手段并熟悉大型仪器设备的分析技术。     

偶联试剂SMCC的一锅法合成

SMCC是一类含有N-羟基琥珀酰亚胺(NHS)活性酯和马来酰亚胺的双功能偶联剂,可以分别将含有巯基和氨基的化合物键接在一起,在生物及化学领域应用广泛。本文采用一锅法将反式氨甲环酸、马来酸酐在DMF作溶剂的条件下反应生成反式氨甲环酸的马来酰胺,再与三氟乙酸酐、N-羟基丁二酰亚胺、三甲基吡啶等反应生成SMCC,对合成SMCC的工艺进行了简单优化,得出了最佳合成条件,总收率可达92%,纯度可达99%以上。     

硝基苯衍生物一锅法合成N-单烷基苯胺化合物

N-单烷基苯胺化合物是染料、医药的重要中间体.以取代硝基苯和醛为原料,钯碳为催化剂,甲酸铵为氢供体,经硝基还原、醛胺缩合、碳氮双键还原反应,在室温下一锅法合成N-单烷基化苯胺化合物,收率和转化率均超过80%.重点对反应配比、甲酸铵用量等工艺参数进行了考察,最佳反应参数为:n(硝基化合物)︰n(甲酸铵)=1︰4;w(硝基化合物)︰w(钯碳)=1︰0.10.并对苯环上取代基对反应的影响进行了探讨,结果显示,由于苯环上供电子基团有利于醛胺缩合物中间体的形成,故反应活性较高.该工艺具有反应温和、安全、操作简单等优点.     

低价钛化合物催化合成咪唑烷的一锅合成法

本文报道了在低价钛催化下,亚胺类化合物和原甲酸三乙酯发生交叉偶联反应以适中产率制得咪唑烷类化合物,并对所得各种不同取代基的咪唑 烷基化合物的产率和异构体比例进行了讨论。产物的构型用核磁共振波谐进行了表征。     

钯催化溴代水杨醛与吡啶硼酸的Suzuki交叉偶联反应

通过研究不同种类钯催化剂[Pd(dppf)2Cl2,Pd(OAc)2,Pd(PPh3)4]、碱(Na2CO3,Na HCO3,K2CO3,K3PO4,Cs2CO3,Cs F)、溶剂(DME/H2O,DMF/H2O,Dioxane/H2O)及温度(70,80,100℃)对5-溴-3-叔丁基水杨醛与吡啶-4-硼酸制备5-(4-吡啶)-3-叔丁基水杨醛化合物的Suzuki偶联反应的影响,开发出一种高效催化吸或供电子基取代的芳基硼酸与吸电子基取代的溴代芳烃的偶联反应的方法,该反应在Pd(PPh3)4,K2CO3,Dioxane/H2O(V∶V=4∶1)、80℃的条件下产率达到97%,且具有分离简单、重现性好的特征;但对供电子基取代的溴代芳烃参与的反应催化效果一般.     

溴代烯烃在金属催化偶联反应中的应用

溴代烯烃是一类重要的有机合成中间体,通过金属催化的偶联反应可以有效地形成碳-碳及碳-杂键.本文综述了溴代烯烃在金属催化偶联反应中应用的最新进展.     

一锅法串联反应合成巯基烟酰胺类衍生物

以巯基烟酸和胺为起始原料,通过一锅法三步串联反应,合成了一系列巯基烟酰胺类衍生物,探索出了一种在温和条件下高效合成巯基烟酰胺类衍生物的方法,解决了以往巯基烟酰胺合成步骤繁琐、条件苛刻、产率低等问题.在未来生物活性分子和药物分子合成上有潜在的应用价值.     

由邻硝基苯胺一锅法合成苯并咪唑化合物

以邻硝基苯胺为原料, 在SnCl2•2H2O/KI/HCl体系中, 100 ℃条件下, 一锅法合成12种苯并咪唑化合物. 该方法以水为溶剂, 条件温和, 操作简单, 催化剂易得, 产率较高, 为该类化合物的合成提供了一种新的便利方法.     

镍络合物催化条件下2,2′-联吡啶的偶联合成

在制备联吡啶的偶联反应中 ,镍化合物和三苯基膦通常是以化学计量参与反应 .我们在对Tiecco报道的偶联反应进行研究的过程中发现 ,这一反应可以在催化条件下进行 .这一改进主要基于投料顺序的改变 ,充分利用零价镍当场 (insitu)生成时的高活性 .将氯化镍、三苯基膦、2 溴吡啶先溶于DMF中 ,然后在 5 0℃时加入锌粉 ,催化偶联生成联吡啶 ,可以获得满意的收率 .同时对三种镍化合物的反应活性作了比较 ,以NiCl2 ·6H2 O活性最高 .     

基于双“click”反应的树枝状化合物的一锅法合成

将叠氮和炔基之间Cu(I)催化的“click”反应以及蒽和马来酰亚胺之间的Diels-Alder反应相结合, 采用“一锅法”技术合成出结构完美且外围含有亲水性寡聚乙二醇(OEG)链段的树枝状化合物4, 产率为75%. 利用核磁共振氢谱、碳谱、紫外、荧光光谱以及MALDI-TOF质谱等对产物进行了表征与分析, 并利用凝胶渗透色谱(GPC)对其纯度进行了测试.     

Glycine-Catalyzed Efficient Synthesis of Pyranopyrazoles via One-Pot Multicomponent Reaction

A facile and convenient protocol is developed for the fast (5–20 min) and high-yielding (85–95%) synthesis of fused pyranopyrazoles from ethyl acetoacetate, hydrazine hydrate, an aldehyde, and malononitrile in the presence of nontoxic, simple, and readily available organocatalyst glycine in aqueous medium at 25 °C.     

Efficient One-Pot Synthesis of Naphthoquinone-Fused Phosphorous Heterocycles via Mannich-Type Reaction

A series of naphthoquinone-fused phosphorus heterocycles was synthesized via a three-component Mannich-type reaction. 2-Chloroethoxylphosphorodichloridite was used as a phosphorus substrate to explore the structure–activity relationships of the 2-position of the heterocycles. One spiral heterocycle compound was structurally characterized by a single-crystal X-ray diffraction analysis.     

Efficient,One-Pot Synthesis of Triazolothiadiazinyl-pyrazolone and Pyrazolyl-triazolothiadiazine Derivatives via Multicomponent Reaction

A one-pot, multicomponent reaction of 3-(2-bromo acetyl)coumarins, 4-amino-5-hydrazino-4H-[1,2,4]triazole-3-thiol, and different derivatives of ethyl 2-(2-(aryl)hydrazono)-3-oxobutanoates provide an efficient and direct method for the synthesis of 4-(arylydrazono)-3-methyl-1-(6-(coumarin-3-yl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-3-yl)-1H-pyrazol-5(4H)-ones (4a–h). A similar methodology was also developed for the synthesis of pyrazolyl-triazolothiadiazines (9a–f) using acetyl acetone, 4-amino-5-hydrazino-4H-[1,2,4]triazole-3-thiol, and different derivatives of phenacylbromide. The resulting products were characterized by analytical and spectral data.     

One-Pot Synthesis of 1,3,4-Thiadiazin-5-yl-chromen-2-one Derivatives via Three-Component Reaction

An expeditious, one-pot reaction has been described for the preparation of 1,3,4-thiadiazin-5-yl-chromen-2-one derivatives. These compounds were synthesized by the reaction of 3-(2-bromoacetyl)coumarin with thiocarbohydrazide and various carbonyl compounds. The newly synthesized compounds were characterized by infrared, ¹H NMR, and mass spectra.     

Synthesis and Characterization of Fluorinated Bisphenols and Tetraphenols via a Simple One-Pot Reaction

Fluorinated bisphenols and tetraphenols have been prepared by the condensation reaction of trifluoromethyl activated ketones with simple bisphenols (including catechol, resorcinol, and hydroquinone) catalyzed by trifluoromethanesulfonic acid, in good yields.

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

One-Pot Synthesis of Hexahydroquinolines via Hantzsch Four-Component Reaction Catalyzed by a Cheap Amino Alcohol

An economic, efficient access to hexahydroquinolines was found. In the presence of threo-(1S,2S)-2-amino-1-(4′-nitrophenyl)-1,3-propanediol, a waste product formed in the production of chloromycetin, a one-pot, four-component Hantzsch reaction of dimedone, aldehydes, ethyl acetoacetate, and ammonium acetate at room temperature furnished hexahydroquinoline derivatives in excellent yield. A possible catalytic mechanism was also suggested.     

Facile One-Pot Synthesis of Aryl,Heteryl Substituted Hydrazono Thiazolyl-Pyrazolone Derivatives via Three-Component Reaction

A facile, one-pot, three-component bis heterocyclized reaction for the synthesis of hydrazonothiazolyl-pyrazolones has been described. Reaction of phenacyl bromides or 3-(2-bromoacetyl)coumarins, with thiosemicarbazide and ethyl 2-(2-arylhydrazono)-3-oxobutanoates in AcOH/NaOAc, gave the corresponding products in good yields. All the synthesized compounds were characterized by their analytical and spectral data.     

镍催化转移缩聚合成全氟环丁基芳基醚聚合物

研究了通过镍催化转移缩聚的方法来合成全氟环丁基芳基醚聚合物.首先,我们以对溴苯酚和1,2-二溴四氟乙烷为起始原料,通过两步反应得到对溴三氟乙烯基芳基醚,进一步加热环化二聚得到单体1,2-二(4-溴苯氧基)六氟环丁烷.该二聚物再与异丙基格氏试剂发生镁交换反应,生成格氏试剂中间体,在催化剂Ni(dppe)Cl2的存在下发生镍催化转移缩聚生成聚合物.研究了反应时间、温度和单体投料比对催化缩聚反应的影响.     

Efficient Synthesis of 4-Phenyl-4H-pyran Derivatives via a DIPEA-catalyzed One-Pot Three-Component Reaction

Russian Journal of Organic Chemistry - A novel one-pot approach has been developed for a high-yield synthesis of 4-phenyl-4H-pyran derivatives by the three-component condensation of dimethyl...     

Synthesis of 2-Methylthio-4H-4-chromenones via Ketene Dithioacetal in the One-Pot Reaction

2-Methylthio-4H-4-chromenone which is key intermediate for the synthesis of 2-methylsulfonyl-4H-4-chromenone, equivalent to 2-halo-4H-4-chromenone, was very easily and efficiently synthesized from 2'-hydroxyacetophenone analogues via ketene dithioacetal in the one-pot reaction.