Iridium-Catalyzed Reductive Allylation of Esters.
Org Lett
; 21(17): 6663-6667, 2019 09 06.
Article
em En
| MEDLINE
| ID: mdl-31397155
ABSTRACT
The catalytic reductive transformation of carboxylic esters into α-branched ethers is described. The procedure pivots on the chemoselective iridium-catalyzed hydrosilylation of ester and lactone functionality to afford a silyl acetal intermediate. Upon treatment with a Lewis acid, these hemilabile intermediates dissociate to form reactive oxocarbenium ions, which can be intercepted by allyltributyltin nucleophiles, resulting in the formation of valuable α-branched alkyl-alkyl ether derivatives. This reductive allylation procedure was found to be amenable to a range of carboxylic ester starting materials, and good chemoselectivity for ethyl over tert-butyl esters was demonstrated. Furthermore, downstream synthetic manipulation of α-amino acid-derived products led to the efficient formation of pyrrolidine, piperidine, and azepane frameworks.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Org Lett
Assunto da revista:
BIOQUIMICA
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Reino Unido