PdII -Catalyzed Enantioselective C(sp3 )-H Arylation of Cyclobutyl Ketones Using a Chiral Transient Directing Group.
Angew Chem Int Ed Engl
; 59(24): 9594-9600, 2020 06 08.
Article
em En
| MEDLINE
| ID: mdl-32155313
ABSTRACT
The use of chiral transient directing groups (TDGs) is a promising approach for developing PdII -catalyzed enantioselective C(sp3 )-H activation reactions. However, this strategy is challenging because the stereogenic center on the TDG is often far from the C-H bond, and both TDG covalently attached to the substrate and free TDG are capable of coordinating to PdII centers, which can result in a mixture of reactive complexes. We report a PdII -catalyzed enantioselective ß-C(sp3 )-H arylation reaction of aliphatic ketones using a chiral TDG. A chiral trisubstituted cyclobutane was efficiently synthesized from a mono-substituted cyclobutane through sequential C-H arylation reactions, thus demonstrating the utility of this method for accessing structurally complex products from simple starting materials. The use of an electron-deficient pyridone ligand is crucial for the observed enantioselectivity. Interestingly, employing different silver salts can reverse the enantioselectivity.
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MEDLINE
Assunto principal:
Paládio
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Ciclobutanos
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Cetonas
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Estados Unidos