imidazo[1,2-a]pyridines by a [3+2] cycloaddition of pyridinium ylide with trifluoroacetonitrile is described. By using 2,2,2-trifluoroacetaldehyde O-(aryl)oxime as convenient precursor of trifluoroacetonitrile, the reaction exhibits a broad substrate scope of pyridinium ylides. The process is a scalable method for the synthesis of potentially bioactive class of 2-trifluoromethyl imidazo[1,2-a]pyridines
描述了通过吡啶鎓叶立德与三氟乙腈的 [3+2] 环加成制备 2-三氟甲基咪唑并 [1,2- a ] 吡啶的一般方法。通过使用 2,2,2-三氟乙醛 O-(芳基)肟作为三氟乙腈的便捷前体,该反应显示出广泛的吡啶鎓叶立德底物范围。该过程是一种可扩展的方法,用于合成具有潜在生物活性的 2-三氟甲基咪唑并 [1,2- a ] 吡啶类化合物。
Synthesis of 2,3-bifunctional imidazo[1,2-a]pyridines through cycloadditions of pyridinium ylides with N-cyano-4-methyl-N-phenylbenzenesulfonamide
作者:Gu Zhan、Hongli Zhao、Dong-Ai Li、Yuling Wu、Huaying Fang、Cheng Peng、Bo Han
DOI:10.1016/j.tetlet.2022.154295
日期:2023.1
In this work, we developed a [3 + 2] cycloadditions/oxidationreaction of pyridinium ylides with N-cyano-4-methyl-N-phenylbenzenesulfonamide for the synthesis of 2,3-bifunctional imidazo[1,2-a]pyridines. The N-cyano-4-methyl-N-phenylbenzenesulfonamide serves as an activated nitrile, exhibiting higher activity than common alkyl or arylnitrile in the reaction. The strategy features high chemoselectivity
咪唑并[1,2- a ]吡啶因其在药物化学中的广泛应用而被公认为“药物偏见”。在这项工作中,我们开发了吡啶叶立德与N -氰基-4-甲基- N -苯基苯磺酰胺的 [3 + 2] 环加成/氧化反应,用于合成 2,3- 双功能咪唑并 [1,2- a ] 吡啶。N-氰基-4-甲基-N-苯基苯磺酰胺作为活性腈,在反应中表现出比普通烷基腈或芳基腈更高的活性。该策略具有高化学选择性、易于获取的材料和广泛的底物范围。放大反应证明了该方法的实用性,咪唑并[1,2- a]吡啶类产品可以很容易地转化为它们的衍生物。
Catalyst‐free oxidative [3+2]‐annulation of (2‐nitroethene‐1,1‐diyl)bis(methylsulfane) and pyridinium ylides: Efficient synthesis of (methylsulfanyl)indolizines heterocycles
A facile and efficient protocol has been developed for the synthesis of (methylsulfanyl)indolizine derivatives via oxidative [3+2]-annulation of bis(methylthio)-2-nitroethylen(BMTNE) and pyridinium ylides under K2CO3. The target products could be obtained in moderate to good yields.
通过双(甲硫基)-2-硝基乙烯(BMTNE)和吡啶叶立德在K 2 CO 3下的氧化[3+2]环化,开发了一种简便有效的方案,用于合成(甲基硫基)中氮茚衍生物。可以以中等至良好的产率获得目标产物。
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