Stereoselective N-Heterocyclic-Carbene-Catalyzed Formal [4 + 2] Cycloaddition: Access to Chiral Heterocyclic Cyclohexenones.
Org Lett
; 25(1): 174-178, 2023 Jan 13.
Article
em En
| MEDLINE
| ID: mdl-36595711
ABSTRACT
The present study reports an asymmetric NHC-catalyzed formal [4 + 2] cycloaddition of heterocyclic alkenes containing a polarized double bond with an azolium-dienolate intermediate generated from α-bromo-α,ß-unsaturated aldehydes without external oxidation of the Breslow intermediate. Heterocyclic cyclohexenones were produced in good isolated yields (typically about 90%) with good stereochemical outcomes (in most cases, dr > 20/1, and ee = 70-99%). The synthetic utility of the protocol was exemplified by the scope of heterocyclic alkenes.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article