作者:Keywan A. Johnson、Soumik Biswas、Daniel J. Weix
DOI:10.1002/chem.201601320
日期:2016.5.23
An improved method for the reductive coupling of aryl and vinyl bromides with alkyl halides that gave high yields for a variety of substrates at room temperature with a low (2.5 to 0.5 mol %) catalyst loading is presented. Under the optimized conditions, difficult substrates, such as unhindered alkenyl bromides, can be coupled to give the desired olefins with minimal diene formation and good stereoretention
提出了一种用于芳基和乙烯基溴与烷基卤的还原偶联的改进方法,该方法在室温下以较低的催化剂负载量(2.5至0.5 mol%)为多种底物提供了高收率。在优化的条件下,可以将难处理的底物(例如未受阻的烯基溴化物)偶联,以形成所需的烯烃,同时减少二烯的形成并保持良好的立体保留性。这些改进的条件对于芳基溴化物也很有效。例如,证实了克级反应的催化剂负载量为0.5 mol%,而催化剂负载量为10 mol%时,反应仅需20分钟即可完成。最后,介绍了一种低成本的单组分预催化剂(bpy)NiI 2(bpy = 2,2'-联吡啶),其在几个月内对空气和水分均稳定。