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Updated: Aug 23, 2025

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Published on: August 1, 2018
A 6-endo-dig Thiolative Cyclization of Yne-Ynamides: Access to Thiodihydropyridin-2-ones
Suresh Kanikarapu1, Manash Protim Gogoi1, Shubham Dutta1
1School of Chemistry, University of Hyderabad, Hyderabad, India 500046.
Abstract:
A straightforward regioselective intramolecular 6-endo-dig cyclization of yne-tethered ynamide is herein developed. The reaction involves an intramolecular enolate attack of ketene-N,O-acetals, generated in situ from yne-ynamide and methanesulfonic acid, to the alkyne moiety activated by a sulfonium cation. The transformation enables access to structurally diverse 5-(arylthio)-3,6-dihydropyridin-2(3H)-ones with broad functional group compatibility. The recovery of S-protecting groups and synthetic applications of the products make the transformation useful.
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