Catalytic Enantioselective Direct Aldol Addition of Aryl Ketones to α-Fluorinated Ketones.
Angew Chem Int Ed Engl
; 59(13): 5359-5364, 2020 03 23.
Article
em En
| MEDLINE
| ID: mdl-31961990
ABSTRACT
The catalytic enantioselective synthesis of α-fluorinated chiral tertiary alcohols from (hetero)aryl methyl ketones is described. The use of a bifunctional iminophosphorane (BIMP) superbase was found to facilitate direct aldol addition by providing the strong Brønsted basicity required for rapid aryl enolate formation. The new synthetic protocol is easy to perform and tolerates a broad range of functionalities and heterocycles with high enantioselectivity (up to >991 e.r.). Multi-gram scalability has been demonstrated along with catalyst recovery and recycling. 1 Hâ
NMR studies identified a 1400-fold rate enhancement under BIMP catalysis, compared to the prior state-of-the-art catalytic system. The utility of the aldol products has been highlighted with the synthesis of various enantioenriched building blocks and heterocycles, including 1,3-aminoalcohol, 1,3-diol, oxetane, and isoxazoline derivatives.
Texto completo:
1
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article