Cobalt-Catalyzed Asymmetric Sequential Hydroboration/Isomerization/Hydroboration of 2-Aryl Vinylcyclopropanes.
Angew Chem Int Ed Engl
; 61(30): e202205619, 2022 07 25.
Article
em En
| MEDLINE
| ID: mdl-35607762
ABSTRACT
A cobalt-catalyzed asymmetric sequential hydroboration/isomerization/hydroboration of 2-aryl vinylcyclopropanes was for the first time reported for the preparation of valuable chiral 1,5-bis(boronates) in good yields with excellent enantioselectivity via asymmetric sequential isomerization/hydroboration of a trisubstituted alkene intermediate. The reaction was carried out smoothly and this protocol was used for asymmetric syntheses of (-)-preclamol in gram-scale. The two primary C(sp3) -B bonds in chiral 1,5-bis(boronates) could be distinguished in iterative Suzuki-Miyaura cross-coupling reaction, delivering chiral 1,2,5-triaryl alkanes with excellent enantioselectivity. Based on experimental and computational studies, a cobalt-hydride species was proposed as the active intermediate in hydroboration, isomerization, and second hydroboration reactions.
Palavras-chave
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Cobalto
/
Alcenos
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
China