A Modular Furanoside Thioether-Phosphite/Phosphinite/ Phosphine Ligand Library for Asymmetric Iridium-Catalyzed Hydrogenation of Minimally Functionalized Olefins: Scope and Limitations
作者:Mercedes Coll、Oscar Pàmies、Montserrat Diéguez
DOI:10.1002/adsc.201200711
日期:2013.1.14
thioether‐phosphite/phosphinite/phosphine ligand library has been synthesized for the iridium‐catalyzed asymmetric hydrogenation of minimally functionalized olefins. These ligands can be prepared efficiently from easily accessible D‐(+)‐xylose. We found that their effectiveness at transferring the chiral information in the product can be tuned by correctly choosing the ligand components. Enantioselectivities were
合成了高度模块化的呋喃糖苷硫醚亚磷酸酯/次膦酸酯/膦配体库,用于铱催化的最小官能化烯烃的不对称氢化。这些配体可以从容易获得的D -(+)-木糖中高效制备。我们发现,可以通过正确选择配体组分来调节其在产品中传递手性信息的有效性。因此,在广泛的E-和Z范围内,对映选择性极好(ee高达99%)使用5-脱氧核糖呋喃糖苷硫醚-亚磷酸酯配体的三取代烯烃。应该指出的是,这些催化剂对相邻极性基团的存在也具有很高的耐受性。对于1,1-二取代的底物,只需改变亚磷酸二芳基酯的构型,就可以高对映选择性获得氢化产物的两种对映异构体。还使用碳酸亚丙酯作为溶剂进行不对称氢化,这使得铱催化剂可以重复使用,同时保持优异的对映选择性。