Dearomative Intramolecular (4+3) Cycloadditions of Thiophenes.
Angew Chem Int Ed Engl
; 63(33): e202407059, 2024 Aug 12.
Article
em En
| MEDLINE
| ID: mdl-38758985
ABSTRACT
Unexpectedly facile dearomative intramolecular (4+3) cycloadditions of thiophenes with epoxy enolsilanes, providing sulfur-bridged cycloadducts, are reported. A total of fifteen thiophene substrates have been found to undergo (4+3) cycloaddition smoothly to produce endo and exo (4+3) adducts in yields of up to 83 % with moderate to good diastereoselectivity. Complete conservation of enantiomeric purity was observed when the optically enriched epoxide was used. The desulfurizing transformations of the sulfur-bridged skeleton of the cycloadducts provide functionalized 6,7-fused bicyclic frameworks consisting of 1,3-cycloheptadiene subunits. Density functional theory calculations reveal the origins of the facile dearomatization of thiophenes in these (4+3) cycloadditions.
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Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article