Rhodium(III)-catalyzed mild and regioselective dearomative spirocyclization of 2-aryl-3-nitrosoindoles with alkynes
Cheng Li1, Bin Zhao1, Guojiang Mao2
1Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, China. gjdeng@xtu.edu.cn.
Abstract:
Herein, we develop a Rh(III)-catalyzed intermolecular regioselective dearomative spirocyclization of 2-aryl-3-nitrosoindoles with alkynes, featuring the redox-neutral and atom-economic construction of spiroindoline-3-one oximes bearing a C2 spirocyclic quaternary carbon center under mild conditions. Both aryl alkyl alkynes and 1,3-diynes generally proceeded smoothly in the reaction with moderate to good regioselectivities. DFT calculations provided in-depth insights into the reaction mechanism and disclosed the origins of the regioselectivities.
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