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A Hg(OTf)2-Catalyzed Enolate Umpolung Reaction Enables the Synthesis of Coumaran-3-ones and Indolin-3-ones

Zhouting Rong*, Weican Hu, Ning Dai and Guoying Qian*

*College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, People’s Republic of China, Email:,

Z. Rong, W. Hu, N. Dai, G. Qian, Org. Lett., 2020, 22, 3245-3250.

DOI: 10.1021/acs.orglett.0c01096

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A Hg(OTf)2-catalyzed N-oxide addition to alkynes forms an enolonium species, that can undergo intramolecular nucleophilic attack by hydroxyl or amino groups, providing various coumaran-3-ones and indolin-3-ones via an enolate umpolung reactivity.

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proposed mechanism

Key Words

benzofuran-3(2H)-ones, 3-oxindoles, pyridine N-oxides

ID: J54-Y2020