摘要
综述了近年来以N-杂环卡宾(NHC)为配体的金属配合物催化的Suzuki偶联反应。由于N-杂环卡宾独特的富电子和位阻特性,在催化反应中能紧密的与金属Pd配位,防止钯黑的产生,Pd-NHC键热稳定性高,避免了过量配体的加入。而且这些配体的富电子性提高了偶联反应的氧化加成速率,其大的空间位阻提高了还原消除速率,N-杂环卡宾成为钯催化的Suzuk i偶联反应中最重要的配体之一。
Suzuki cross coupling reactions catalyzed by N - heterocyclic carbene - metal complexes were reviewed. The N - heteroeyclic carbenes coordinate tightly to palladium due to their tunable electronic and steric properties, thus disfavouring the formation of black. The thermal stability of the Pd -NHC bond avoids the necessity for excess ligand. Moreover, the electron -rich nature of these ligands enhances the rate of oxidative addition and their steric bulk increases the rate of reductive elimination. The N - heterocyclic carbenes have became one of the most important ligands to palladium - catalyzed Suzuki coupling reactions.
出处
《宜春学院学报》
2008年第4期1-5,78,共6页
Journal of Yichun University
基金
江西省教育厅科技计划项目(赣教技字[2007]310号)
宜春市重点科技计划项目(宜科字[2006]56号)
