Tf 2 O介导的α-酰基-β-(2-氨基吡啶基)丙烯酰胺的环化:获得N取代的4 H-吡啶基[1,2- a ]嘧啶-4-亚胺
摘要:
由三氟甲磺酸酐(Tf 2 O)介导的α-酰基-β-(2-氨基吡啶基)丙烯酰胺开发了一种N-取代的4 H-吡啶并[1,2 - a ]嘧啶-4-亚胺的简便有效的直接合成方法在2-氯吡啶存在下。该酰胺活化方案具有反应条件温和,操作简单,产率高和化学选择性高的特点,并且还可以通过实用的一锅法应用于取代的4 H-吡啶并[1,2- a ]嘧啶-4-酮的合成。程序。
A facile and efficient one-pot synthesis of substitutedthieno[2,3-b]pyridines has been developed. Treatment of enaminones, such as 2-acetyl-3-(dimethylamino)propenamides and -propenoates, with 2-cyanothioacetamide in the presence of potassium carbonate in N,N-dimethylformamide at 80 ˚C followed by addition of methylene-active bromides at room temperature provided, via intramolecular cyclization,
已经开发了一种简便,高效的一锅法合成取代的噻吩并[2,3- b ]吡啶。在80°C下于N,N-二甲基甲酰胺中的碳酸钾存在下,用2-氰基硫代乙酰胺处理2-氨基-3-(二甲基氨基)丙烯酰胺和-丙烯酸酯等烯胺酮,然后在室温下添加亚甲基活性溴化物通过分子内环化提供2,3,5,6-四取代的噻吩并[2,3- b ]吡啶的温度为78-90%。该方案结合了噻吩并[2,3- b ]吡啶环的构建和修饰,增加了最终材料的结构多样性,这些最终产品来自易于获得的材料。 烯胺酮-环化-杂环-吡啶-2(1 H)-硫酮-噻吩并[2,3- b ]吡啶
Efficient Synthesis of Pyridin‐2(1<i>H</i>)‐ones From a Series of Readily Available Enaminones Under Mild Conditions
作者:Bao‐chang Gao、Yu‐feng Sun、Jun Wang、Li‐wu Zu、Xu Zhang、Wen‐bin Liu
DOI:10.1002/jhet.3333
日期:2018.12
A facile and efficient synthesis of substituted pyridin‐2(1H)‐ones has been developed by the reaction of readily available enaminones with malononitrile in ethanol at room temperature in yields of 85–95%. This protocol, which combines construction and modification of the pyridin‐2(1H)‐ones ring underVilsmeierconditions (dimethylformamide/POCl3), increases the structural diversity of the final products
A facile and efficient one-potsynthesis of polysubstituted pyridin-2(1H)-ones from readily available enaminones and the cyanomethyl sulfonium bromide salt in the presence of cesium carbonate is developed, and a mechanism involving sequential nucleophilic vinylic substitution (S(N)V), intramolecular nucleophilic cyclization and dealkylation reactions is proposed.
Cyclization of a variety of beta-aminoacrylamides in the presence of iodosobenzene (PhIO) is described. This process features mild reaction conditions, simple execution, and high chemoselectivity and thereby provides an efficient protocol for the divergent synthesis of substituted isoxazoles and 2H-azirines via switchable N-O and N-C bond formation controlled by simply varying the beta-substituent R-3 of the readily available substrates.
Vilsmeier Reaction of 3-Aminopropenamides: One-Pot Synthesis of Pyrimidin-4(3<i>H</i>)-ones
A facile one-pot synthesis of pyrimidin-4(3H)-ones was developed via reactions of a series of readily available 3-aminopropenamides with varied Vilsmeier reagents, and a mechanism involving sequential halogenation, formylation, and intramolecular nucleophilic cyclization is proposed.