Aromatic CC Bonds as Dipolarophiles: Facile Reactions of Uncomplexed Electron-Deficient Benzene Derivatives and Other Aromatic Rings with a Non-Stabilized Azomethine Ylide
作者:Sunyoung Lee、Sonia Diab、Pierre Queval、Muriel Sebban、Isabelle Chataigner、Serge R. Piettre
DOI:10.1002/chem.201201238
日期:2013.5.27
Non‐stabilized azomethine ylide 4 a reacts smoothly at room temperature with a variety of uncomplexed aromatic heterocycles and carbocycles on the condition that the ring contains at least one or two electron‐withdrawing substituents, respectively. Aromatic substrates, including pyridine and benzene derivatives, participate as 2 π components in [3+2] cycloaddition reactions and interact with one, two
非稳定的甲亚胺叶立德4 a在环上分别含有至少一个或两个吸电子取代基的条件下,在室温下可与各种未络合的芳族杂环和碳环平滑反应。芳香族底物(包括吡啶和苯衍生物)作为2π组分参与[3 + 2]环加成反应,并根据其结构和取代方式与一,二或三当量的叶立德发生相互作用。因此,该方法提供了高度有用的多环结构,其以有用的产率包含一个至三个之间的吡咯烷基环。这些结果表明,环加成反应的位点选择性强烈取决于取代基的性质和位置。在大多数情况下,第二个1 3-偶极反应发生在与第一个吡咯烷基环相对的面上。DFT对模型化合物的计算表明,协同作用的机制具有较低的活化势垒。