Ligand-Promoted Nickel-Catalyzed para-Selective Carboxylation of Anisoles.
Org Lett
; 24(11): 2155-2159, 2022 Mar 25.
Article
em En
| MEDLINE
| ID: mdl-35285647
ABSTRACT
It has always been a challenge in free radical chemistry to control site selectivity during the reaction of free radicals with aromatic rings. Herein, we report the site-selective carboxylation of anisoles through the direct reaction of the bromoform radical with a benzene ring at the para position under the assistance of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline with nickel(II) as the catalyst. A wide variety of anisoles were compatible, leading to para-carboxylated products in moderate to good yields. A preliminary mechanistic study suggested that the Ni(II) complex coordinates with the methoxyl group of the aromatic ring, which may have increased the steric hindrance at the ortho and meta positions, while this weak interaction reduces the aromaticity of the aromatic ring, affording an activated phenyl ring, thereby leading to highly para-selective carboxylation.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Org Lett
Assunto da revista:
BIOQUIMICA
Ano de publicação:
2022
Tipo de documento:
Article