Divergent Construction of N-Doped Polycyclic Aromatic Hydrocarbons with Indole as the Nitrogen Source Building Block
Divergent Construction of N-Doped Polycyclic Aromatic Hydrocarbons with Indole as the Nitrogen Source Building Block
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DOI：
10.1002/chem.202300140
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发表时间：
2023-03-08
影响因子：
4.3
通讯作者：
Xu，Xinfang
中科院分区：
文献类型：
--
作者：
Bao，Ming;Xie，Xiongda;Xu，Xinfang
描述了一种Ag/Au催化的嵌入炔的重氮酮与吲哚的发散级联反应。初步的机理研究表明，该反应通过原位形成的异苯并吡喃中间体与吲哚的[4+2]-环加成，然后通过顺序的逆迈克尔加成/卡宾N-H插入过程，在金催化下得到苯并[i]菲啶产物;而当反应由银催化剂催化时，脱芳构化/rearomatization顺序有利地发生，通常以高至优异的产率得到苯并[B]咔唑。 值得注意的是，这是使用吲哚作为亲二烯体与异苯并吡喃鎓物质进行环加成的罕见例子，为选择性构建具有结构多样性和广泛官能团相容性的N掺杂多环芳烃（PAH）提供了简洁实用的方法。
An Ag/Au‐catalyzed divergent cascade reaction of alkyne embedded diazoketones with indoles has been described. Preliminary mechanistic studies indicate that the reaction goes through a [4+2]‐cycloaddition of an in situ formed isobenzopyrylium intermediate with indole, followed by a sequentialretro‐Michael addition/carbene N−H insertion process to give the benzo[i]phenanthridines products with gold catalysis; whereas a dearomatization/rearomatization sequence occurs favourably when the reaction is catalyzed by a silver catalyst, delivering benzo[b]carbazoles in generally high to excellent yields. Notably, this is a rare example of using indole as the dienophile for cycloaddition with the isobenzopyrylium species, providing a concise and practical approach for the selective construction of N‐doped polycyclic aromatic hydrocarbons (PAHs) with structural diversity and broad functional‐group compatibility.