Changing the Palladium Coordination to Phosphinoimidazolines with a Remote Triazole Substituent
作者:Verónica de la Fuente、Rocío Marcos、Xacobe C. Cambeiro、Sergio Castillón、Carmen Claver、Miquel A. Pericàs
DOI:10.1002/adsc.201100684
日期:2011.12
Phosphinoimidazoline (PHIM) ligands bearing a triazolylmethyl substituent at the sp3 nitrogen atom in the imidazoline ring lead to highly improved enantioselectivity (up to 99% ee) in allylic substitution reactions with respect to analogous ligands with substituents lacking the triazole unit. NMR and theoretical studies support a shift in the coordination mode of the PHIM ligand to palladium, triggered
在咪唑啉环的sp 3氮原子上带有三唑基甲基取代基的膦亚咪唑啉(PHIM)配体,相对于具有缺少三唑单元的取代基的类似配体而言,在烯丙基取代反应中极大地提高了对映选择性(高达99%ee)。NMR和理论研究支持PHIM配体与钯的配位模式转变,这是由于与三唑单元发生非常有利的相互作用而引起的。