Divergent Construction of N‐Doped Polycyclic Aromatic Hydrocarbons with Indole as the Nitrogen Source Building Block

作者：Ming Bao, Xiongda Xie, Jingjing Huang, Michael P. Doyle, Zhi Ren, Haibo Yue, Xinfang Xu · 发表于：Chemistry - A European Journal · 年份：2023 · DOI：10.1002/chem.202300140 · 被引用次数：8 · 研究领域：Cyclopropane Reaction Mechanisms、Catalytic C–H Functionalization Methods、Catalytic Alkyne Reactions

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 sequential retro-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.