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Access to Bromo-γ-butenolides via Zwitterion-Catalyzed Rearrangement of Cyclopropene Carboxylic Acids

Rong-Bin Hu, Shengsheng Qiang, Yung-Yin Chan, Jingxian Huang, Tianyue Xu and Ying-Yeung Yeung*

*Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, Email:

R.-B. Hu, S. Qiang, Y.-Y. Chan, J. Huang, T. Xu, Y.-Y. Yeung, Org. Lett., 2021, 23, 9533-9537.

DOI: 10.1021/acs.orglett.1c03751 (free Supporting Information)

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Zwitterionic catalysts promote the formation of halogenated γ-butenolides from cyclopropene carboxylic acids in the presence of N-haloamides as the halogen sources. The catalytic protocol could also be applied to the synthesis of halogenated pyrrolones by using cyclopropene amides as the starting materials.

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proposed mechanism

Key Words

butenolides, organocatalysis

ID: J54-Y2021