Silver-Catalyzed Enantioselective Propargylic C-H Bond Amination through Rational Ligand Design.
J Am Chem Soc
; 142(30): 12930-12936, 2020 07 29.
Article
en En
| MEDLINE
| ID: mdl-32659081
ABSTRACT
Asymmetric C-H amination via nitrene transfer is a powerful tool to prepare enantioenriched amine precursors from abundant C-H bonds. Herein, we report a regio- and enantioselective synthesis of γ-alkynyl γ-aminoalcohols via a silver-catalyzed propargylic C-H amination. The protocol was enabled by a new bis(oxazoline) (BOX) ligand designed via a rapid structure-activity relationship (SAR) analysis. The method utilizes accessible carbamate esters bearing γ-propargylic C-H bonds and furnishes versatile products in good yields and excellent enantioselectivity (90-99% ee). The putative Ag-nitrene is proposed to undergo enantiodetermining hydrogen-atom transfer (HAT) during the C-H amination event. Density functional theory calculations shed insight into the origin of enantioselectivity in the HAT step.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Plata
/
Amino Alcoholes
Idioma:
En
Revista:
J Am Chem Soc
Año:
2020
Tipo del documento:
Article
País de afiliación:
Estados Unidos