Ring-Opening Reconstruction of Indoles Enabled by C–N Bond Cleavage: Synthesis of Benzo[ c ]pyrazolo[3,4- h ][2,6]naphthyridine Derivatives

作者：You Zhou, Li‐Sheng Wang, Zehua Li, Shuang‐Gui Lei, Bo‐Cheng Tang, Ping He, Kai‐Lu Zheng, Yu Lan, An‐Xin Wu · 发表于：Organic Letters · 年份：2025 · DOI：10.1021/acs.orglett.5c03710 · 被引用次数：11 · 研究领域：Catalytic C–H Functionalization Methods、Radical Photochemical Reactions、Catalytic Cross-Coupling Reactions

Here we report the iodine-mediated tandem process of indole-ring-opening reconstruction, which accomplishes scaffold hopping from indoles to polycyclic heteroaromatics (PHAs), offering the advantages of simple operation and easily accessible substrates. The proposal is compatible with a wide range of active molecules and natural products, affording derivatives endowed with both thermally activated delayed fluorescence (TADF) and aggregation-induced emission (AIE) properties. Importantly, the reaction mechanism was further investigated by density functional theory (DFT) calculations, confirming that the reaction involves chemoselective formation of a diene and a stereoselective [4 + 2] cycloaddition. The analyses further clarify that a hindering group at the 2-position of the indole is critical for driving the C-N bond ring-opening and recombination process. This work highlights the versatility of the approach as a strategic extension to advancing indole chemistry and skeletal reconstruction.