Intermolecular Dehydrative [4 + 2] Aza-Annulation of N-Arylamides with Alkenes: A Direct and Divergent Entrance to Aza-Heterocycles
Ying-Hong Huang, Shu-Ren Wang, Dong-Ping Wu, Pei-Qiang Huang*
*Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, P.R. China, Email: pqhuangxmu.edu.cn
Y.-H. Huang, S.-R. Wang, D.-P. Wu, P.-Q. Huang, Org. Lett., 2019, 21, 1681-1685.
DOI: 10.1021/acs.orglett.9b00233 (free Supporting Information)
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Upon activation with trifluoromethanesulfonyl anhydride, secondary N-arylamides undergo smooth intermolecular dehydrative [4 + 2] aza-annulation with alkenes under mild conditions to give 3,4-dihydroquinolines, amenable to further functionalization. The use of NaBH4 or DDQ in a subsequent step enables the synthesis of tetrahydroquinolines or quinolines, respectively.
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