Iridium-Catalyzed Asymmetric Hydrogenation Yielding Chiral Diarylmethines with Weakly Coordinating or Noncoordinating Substituents
作者:Päivi Tolstoy、Mattias Engman、Alexander Paptchikhine、Jonas Bergquist、Tamara L. Church、Abby W.-M. Leung、Pher G. Andersson
DOI:10.1021/ja9013375
日期:2009.7.1
in pharmaceuticals and natural products, making the synthetic methods that form these chiral centers are important in industry. We have applied iridium complexes with novel N,P-chelating ligands to the asymmetric hydrogenation of trisubstituted olefins, forming diarylmethine chiral centers in high conversions and excellent enantioselectivities (up to 99% ee) for a broad range of substrates. Our results
含二芳基次甲基的立体中心存在于药物和天然产物中,使得形成这些手性中心的合成方法在工业中很重要。我们已将具有新型 N,P 螯合配体的铱配合物应用于三取代烯烃的不对称氢化,以高转化率和优异的对映选择性(高达 99% ee)形成二芳基次甲基手性中心,适用于广泛的底物。我们的结果支持这样一种假设,即催化剂一个特定区域的空间位阻在立体选择中起着关键作用,因为在前手性碳上几乎没有差异的底物的氢化以高对映选择性发生。结果,即使当前手性碳带有例如苯基和对甲苯基基团时,也能获得出色的立体辨别力。