Autor: |
Taka Aki Hanaoka, Yoshihiro Kubota, Kazuhiko Takeuchi, Yoshihiro Sugi |
Rok vydání: |
1996 |
Předmět: |
|
Zdroj: |
Journal of Molecular Catalysis A: Chemical. 111:L187-L192 |
ISSN: |
1381-1169 |
Popis: |
Palladium-catalyzed aryloxycarbonylation of aryl bromides and iodides show contrastive reactivities with respect to the kind of phenoxides. The carbonylation of bromides with hindered potassium phenoxides in benzene gives ester products in high yields, while that with non-hindred PhOK gives almost no ester product under the same conditions. In contrast, the carbonylation of iodides with hindered potassium phenoxides gives no ester, while that with non-hindered PhOK provides ester products in high yields. Variant reductive elimination steps from aroyl palladium halide species to ester products and Pd(0) species are proposed depending on the steric and electronic properties of the phenoxides and aryl halides. They involve a stepwise ligand exchange path and a concerted path. |
Databáze: |
OpenAIRE |
Externí odkaz: |
|