Asymmetric Allylic Alkylation with Deconjugated Carbonyl Compounds: Direct Vinylogous Umpolung Strategy.
Angew Chem Int Ed Engl
; 58(27): 9210-9214, 2019 Jul 01.
Article
em En
| MEDLINE
| ID: mdl-31062895
ABSTRACT
An atom-economic and highly efficient vinylogous umpolung strategy is developed for deconjugated carbonyl compounds, which generate electron-deficient π-allylpalladium complexes with Pd(OAc)2 under ligand-free conditions. In cooperation with a chiral-phosphonium-based phase-transfer catalyst, the asymmetric direct oxidative allylic alkylations of 3-substituted oxindoles are furnished under O2 atmosphere. The γ- or even remote ϵ-regioselective alkylation products, with substantial substituents, are delivered with excellent enantioselectivity, and can be further used to access diverse chiral spirocyclic architectures effectively. The Mukaiyama dienol silyl ether can be utilized similarly, indicating that the current active π-allylpalladium species results from tautomerization of the PdII -dienolate intermediate.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
China