One-Pot Synthesis of 2-Acetyl-1H-pyrroles from N-Propargylic β-Enaminones via Intermediacy of 1,4-Oxazepines
Nilay Kanova, Buse Aysen Dundar, Yilmaz Kelgokmen and Metin Zora*
*Department of Chemistry, Middle East Technical University, 06800 Ankara, Turkey, Email: zorametu.edu.tr
N. Kanova, B. A. Dundar, Y. Kelgokmen, M. Zora, J. Org. Chem., 2021, 86, 6289-6304.
DOI: 10.1021/acs.joc.1c00077
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Abstract
When treated with zinc chloride in refluxing chloroform, N-propargylic β-enaminones produced in situ 2-methylene-2,3-dihydro-1,4-oxazepines, which, upon further refluxing in methanol with zinc chloride, afforded 2-acetyl-1H-pyrroles in good yields. This one-pot two-step protocol was found to be general for a wide variety of substrates with good functional group tolerance.
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proposed mechanism
Key Words
ID: J42-Y2021