Cobalt(II) Porphyrin‐Catalyzed Intramolecular Cyclopropanation of N‐Alkyl Indoles/Pyrroles with Alkylcarbene: Efficient Synthesis of Polycyclic N‐Heterocycles |
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| Authors: | Annapureddy Rajasekar Reddy Fei Hao Kai Wu Cong‐Ying Zhou Prof?Dr Chi‐Ming Che |
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| Institution: | 1. HKU Shenzhen Institute of Research & Innovation, Shenzhen, China;2. State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China |
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| Abstract: | A protocol on chemoselective cobalt(II) porphyrin‐catalyzed intramolecular cyclopropanation of N‐alkyl indoles/pyrroles with alkylcarbenes has been developed. The reaction enables the rapid construction of a range of nitrogen‐containing polycyclic compounds in moderate to high yields from readily accessible materials. These N‐containing polycyclic compounds can be converted into a variety of N‐heterocycles with potential synthetic and biological interest. Compared to their N‐tosylhydrazone counterparts, the use of bulky N‐2,4,6‐triisopropylbenzenesulfonyl hydrazones as carbene precursors allows cyclopropanation to occur under milder reaction conditions. |
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| Keywords: | carbenes cobalt fused-ring systems heterocycles porphyrinoids |
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