Highly efficient Heck olefin arylation in the presence of iminophosphine??????palladium(0) complexes

详细信息    查看全文

• 作者：Scrivanti ; Alberto ; Bertoldini ; Matteo ; Matteoli ; Ugo ; Beghetto ; Valentina ; Antonaroli ; Simonetta ; et. al.
• 关键词：Palladium ; Iminophosphine– ; palladium(0) complexes ; Heck reaction ; Aryl bromides
• 刊名：Journal of Molecular Catalysis. A, Chemical
• 出版年：2005
• 出版时间：July 1, 2005
• 年：2005
• 卷：235
• 期：1-2
• 页码：12-16
• 全文大小：81.4 K

文摘

The Heck coupling of aryl bromides with olefins such as styrene or butyl acrylate is efficiently catalysed by the iminophosphine–palladium(0) complex [Pd(dmfu)(P-N)] (dmfu = dimethyl fumarate; P-N = 2-(PPh₂)C₆H₄-1-CHNC₆H₄OMe-4) (1) in polar solvents. With activated aryl bromides such as 4-bromoacetophenone turnover numbers of up to 20,000 can be achieved at 140 °C in 2 h. The presence of electron-donating groups leads to decreased reaction rates, nevertheless, high substrate conversions can be obtained in reasonable reaction times. Kinetic studies indicate that complex 1 is only a precursor of the actual catalytic species. Experiments aimed to demonstrate the intervention of metallic palladium did not lead to conclusive findings.