NiCl<sub>2</sub>(dppe)-Catalyzed Cross-Coupling of Aryl Mesylates, Arenesulfonates, and Halides with Arylboronic Acids
作者:Virgil Percec、Geoffrey M. Golding、Jan Smidrkal、Oliver Weichold
DOI:10.1021/jo049940i
日期:2004.5.1
the cross-coupling of electron-poor aryl mesylates, tosylates, chlorides, bromides, and iodides. This catalyst was also efficient in the cross-coupling of aryl bromides and iodides containing electron-donating substituents. Most surprisingly, the replacement of the excess dppe from NiCl2(dppe)/dppe with excess PPh3 generated NiCl2(dppe)/PPh3, which was found to be reactive for the cross-coupling of
NiCl 2(dppe)-,NiCl 2(dppb)-,NiCl 2(dppf)-,NiCl 2(PCy 3)2-和NiCl 2(PPh 3)2催化的先前的交叉偶联研究据报道,在没有还原剂的情况下,未报告的甲磺酸甲磺酸酯和含有芳基硼酸的具有吸电子和供电子取代基的芳烃芳磺酸酯,氯化物,溴化物和碘化物。NiCl 2(dppe)是唯一在所研究的两种溶剂甲苯和二恶烷中表现出高且不依赖于溶剂的活性的催化剂。NiCl 2(dppe)与过量的dppe,NiCl2(dppe)/ dppe在贫电子芳基甲磺酸酯,甲苯磺酸酯,氯化物,溴化物和碘化物的交叉偶联中具有反应性。该催化剂在含有给电子取代基的芳基溴化物和碘化物的交叉偶联中也是有效的。最令人惊讶的是,用过量的PPh 3取代了NiCl 2(dppe)/ dppe中的过量dppe产生了NiCl 2(dppe)/ PPh 3,这被发现对富电子和电子-电子的交叉耦