Enantio- and Diastereoselective Synthesis of Chiral Tetrasubstituted α-Amino Allenoates Bearing a Vicinal All-Carbon Quaternary Stereocenter with Dual-Copper-Catalysis.
Angew Chem Int Ed Engl
; 62(31): e202305680, 2023 Aug 01.
Article
em En
| MEDLINE
| ID: mdl-37261939
ABSTRACT
The skeletons of chiral tetrasubstituted allenes bearing a vicinal all-carbon quaternary stereocenter are of importance but still challenging to synthesize. Herein, we report enantio- and diastereoselective γ-additions of 1-alkynyl ketimines with dual-copper-catalysis under mild conditions, affording chiral tetrasubstituted α-amino allenoates bearing a vicinal all-carbon quaternary stereocenter in high yields (up to 99 % yield) with excellent enantioselectivities (up to 99 % ee) and diastereoselectivities (up to >20 1 dr). Importantly, the stereodivergent synthesis of the products was realized by the asymmetric γ-addition reaction and the Grignard reagent promoted epimerization. Moreover, the dual-copper-catalyzed γ-addition reactions were smoothly applied to a gram-scale reaction and adopted to introduce chiral tetrasubstituted allenyl moieties into bioactive molecules. Mechanistic experiments and density functional theory (DFT) calculations demonstrated that the asymmetric γ-addition reactions were catalyzed by double chiral copper catalysts.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Ano de publicação:
2023
Tipo de documento:
Article