Palladium-catalyzed direct arylation of 5-chloropyrazoles: a selective access to 4-aryl pyrazoles. - Université de Rennes Accéder directement au contenu
Article Dans Une Revue Journal of Organic Chemistry Année : 2012

Palladium-catalyzed direct arylation of 5-chloropyrazoles: a selective access to 4-aryl pyrazoles.

Résumé

The use of a temporary protection by a chloro group at C5 of pyrazoles allows the synthesis of the 4-arylated pyrazoles, which were previously inaccessible by palladium-catalyzed direct arylation, with complete regioselectivity and in high yields using in most cases as little as 0.5-0.1 mol % Pd(OAc)(2) as the catalyst with electron-deficient aryl bromides. Moreover, from 5-chloro-1,3-dimethylpyrazole, sequential catalytic C4 arylation, dechlorination, catalytic C5 arylation reactions allowed the synthesis of a 4,5-diarylated pyrazole derivative.

Domaines

Catalyse
Fichier non déposé

Dates et versions

hal-00805289 , version 1 (27-03-2013)

Identifiants

Citer

Tao Yan, Lu Chen, Christian Bruneau, Pierre H. Dixneuf, Henri Doucet. Palladium-catalyzed direct arylation of 5-chloropyrazoles: a selective access to 4-aryl pyrazoles.. Journal of Organic Chemistry, 2012, 77 (17), pp.7659-64. ⟨10.1021/jo301047v⟩. ⟨hal-00805289⟩
47 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More