Exploring Cyclization Strategies to Access Stemona Alkaloids: Subtle Effects Influencing Reactivity in Intramolecular Michael Additions.
Org Lett
; 23(21): 8494-8498, 2021 11 05.
Article
en En
| MEDLINE
| ID: mdl-34677072
ABSTRACT
This report investigates the fundamental basis for rather surprising patterns of reactivity in Brønsted acid-mediated cyclizations of pyrrole substrates bearing pendant Michael acceptors that were identified during syntheses of Stemona alkaloids. Integrated experimental and theoretical studies reveal the profound influence that substituent effects have on the viability of these transformations. Additionally, we identify that electronic effects, in addition to barrier-lowering secondary orbital interactions within transition states, account for the exclusive preference for 7-endo-trig cyclizations over 6-exo-trig cyclizations.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Org Lett
Asunto de la revista:
BIOQUIMICA
Año:
2021
Tipo del documento:
Article
País de afiliación:
Australia