Synthesis of N-aryl imidazoles catalyzed by copper nanoparticles on nanosized silica-coated maghemite
作者:Fabiana Nador、María Alicia Volpe、Francisco Alonso、Gabriel Radivoy
DOI:10.1016/j.tet.2014.04.003
日期:2014.9
A magnetically recoverable catalyst consisting of copper nanoparticles (CuNPs) on nanosized silica-coated maghemite is presented. The catalyst has been prepared under mild conditions by mixing the magnetic support with a freshly prepared suspension of CuNPs obtained by fast reduction of anhydrous CuCl2 with lithium sand and a catalytic amount of DTBB (4,4′-di-tert-butylbiphenyl) as electron carrier
提出了一种由铜纳米颗粒(CuNPs)组成的磁性可回收催化剂,该催化剂位于纳米级二氧化硅包覆的磁赤铁矿上。催化剂是在温和条件下制备的,方法是将磁性载体与新制备的CuNPs悬浮液混合,该悬浮液是通过用锂砂快速还原无水CuCl 2和催化量的DTBB(4,4'-二叔丁基联苯)得到的。电子载体。该铜基催化剂已显示出在无配体条件下使用(杂)芳基溴化物和碘化物作为芳基化剂在咪唑的N-(杂)芳基化中非常有效。该催化剂易于通过外部磁体回收,并且可以在三个N-芳基化循环中重复使用,而不会明显降低催化活性。