Synthesis of New Dicationic Azolium Salts and Their Application as NHC Precursors in Suzuki-Miyaura Coupling
作者:Jürgen Liebscher、Sadaf Khan
DOI:10.1055/s-0029-1218837
日期:2010.8
Novel dicationic azolium salts were developed as N-heterocyclic carbene (NHC) precursors wherein two 1,2,3-triazolium, one 1,2,3-triazolium and one imidazolium, or two imidazolium units, are tethered to each other through alkylene bridges. These dicationic systems were applied as precursors for ligands in palladium-catalyzed Suzuki-Miyaura couplings using different leaving groups. Interestingly, the
研发了新型的偶氮鎓盐作为N-杂环卡宾(NHC)前体,其中两个1,2,3-三唑鎓,一个1,2,3-三唑鎓和一个咪唑鎓或两个咪唑鎓单元通过亚烷基桥相互束缚。这些化学系统用作使用不同离去基团在钯催化的Suzuki-Miyaura偶联中作为配体的前体。有趣的是,咪唑鎓和1,2,3-三唑鎓单元的组合比单一的盐或表现出两个咪唑鎓或两个1,2,3-三唑鎓单元的指示剂更好。事实证明,芳基氯化物,碘化物和三氟甲磺酸酯是这种新型催化系统的最佳底物。 环加成-交叉偶联-催化-烷基化-杂环