Palladium-Catalyzed Intramolecular Cyclization of Ynamides: Synthesis of 4-Halo-oxazolones
Hai Huang, Guangke He, Guohao Zhu, Xiaolin Zhu, Shineng Qiu and Hongjun Zhu*
*Department of Applied Chemistry, College of Sciences, Nanjing Tech University, Nanjing 211816, People’s Republic of China, Email: zhuhjnjtech.edu.cn
H. Huang, G. He, G. Zhu, X. Zhu, S. Qiu, H. Zhu, J. Org. Chem., 2015, 80, 3480-3487.
DOI: 10.1021/acs.joc.5b00071 (free Supporting Information)
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A mild, rapid, and efficient Pd(PPh3)4-catalyzed intramolecular cyclization of N-alkynyl alkyloxycarbamates with CuCl2 or CuBr2 provides 4-halo-oxazolones with good functional group tolerance. 4-halo-oxazolones can serve as precursors for Pd-catalyzed cross-coupling reactions.
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