Phosphine mono- and bis-ylide palladacycles as homogeneous molecular precatalysts: Simple and efficient protocol greatly facilitate Suzuki and Heck coupling reactions
作者:Seyyed Javad Sabounchei、Mohsen Ahmadi、Mohammad Panahimehr、Fateme Akhlaghi Bagherjeri、Zahra Nasri
DOI:10.1016/j.molcata.2014.01.002
日期:2014.3
bis-ylide palladacycles as catalyst precursors were used in Suzuki and Heck cross-coupling reactions with different aryl halides including electron-rich and electron-deficient substituents. These coupling reactions could proceed smoothly in air under optimized reaction conditions (Suzuki coupling: 0.001 mol% of palladacycle, Cs2CO3 in DMF at 110 °C; Heck coupling: 0.001 mol% of palladacycle, K2CO3 in
湿气/空气稳定且坚固的膦单环和双环内酯化合物可作为铃木的前体用于Suzuki和Heck与不同芳基卤化物(包括富电子和缺电子取代基)的交叉偶联反应中。这些偶联反应可以在最佳反应条件下在空气中顺利进行(铃木偶联:DMF中110°C时为0.001 mol%的Palladacycle,Cs 2 CO 3; Heck偶联:为Palladacycle的0.001 mol%,K 2 CO 3(在130°C的NMP中)。过滤实验和中毒研究表明,膦-叶立德Palladacycles在反应条件下分解形成活性Pd(0)均质物种。这些均相催化剂在催化剂负载量低的情况下表现出高催化活性,从而提供了所需产物的高收率。在这些偶联反应中五元的palladacycle [[P ^ C)PdCl 2 ](1)的应用产生了可比的七元类似物[(C ^ C)PdCl 2 ](2)的催化活性。)。我们发现在适当的Suzuki和Hec