Phosphine-Free Palladium Catalytic System for the Selective Direct Arylation of Furans or Thiophenes bearing Alkenes and Inhibition of Heck-Type Reaction
作者:Lu Chen、Julien Roger、Christian Bruneau、Pierre H. Dixneuf、Henri Doucet
DOI:10.1002/adsc.201100193
日期:2011.10
Palladium acetate associated to potassium carbonate as catalytic system has been found to efficiently catalyse the direct 5-arylation of furans or thiophenes bearing enal, enone or acrylate functions at carbon C-2, and to inhibit the Heck-type reaction. The nature of the base is crucial to control the selectivity of the arylation. In the presence of electron-deficient aryl bromides and potassium carbonate
已发现与碳酸钾缔合的乙酸钯作为催化体系可有效催化在碳C-2上带有烯,烯酮或丙烯酸酯功能的呋喃或噻吩的直接5芳基化,并抑制Heck型反应。碱的性质对于控制芳基化的选择性至关重要。在缺电子芳基溴化物和碳酸钾作为碱的存在下,直接芳基化是有利的,而使用的氟化钾,得到选择性赫克型产物,和三- Ñ丁胺还原加成产物。