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Potassium tert ‐Butoxide‐Catalyzed Synthesis of α ‐Methylene‐ β ‐Lactams from Propiolamides
Author(s) -
Claus Angelica R.,
Goulart Tales A. C.,
Back Davi F.,
Zeni Gilson
Publication year - 2021
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.202100176
Subject(s) - chemistry , methylene , protonation , catalysis , stereoselectivity , medicinal chemistry , nucleophile , carbon–carbon bond , stereochemistry , organic chemistry , ion
We reported herein the regio‐ and stereoselective synthesis of α ‐methylene‐ β ‐lactams via a 4‐ exo ‐dig‐cyclization of N ‐benzyl‐ N ‐methyl‐propiolamides catalyzed by a base. The experimental evidence suggests that this transformation proceeds via a concerted ionic cyclization with a carbon nucleophilic addition to the carbon‐carbon triple bond, followed by protonation of the vinyl species promoted by tert ‐butanol. The obtained α ‐methylene‐ β ‐lactams were suitable substrates for the Heck coupling conditions affording the corresponding products via carbon‐carbon bond formation.