Development of 4,4‘-Substituted-XylBINAP Ligands for Highly Enantioselective Hydrogenation of Ketones
作者:Helen L. Ngo、Wenbin Lin
DOI:10.1021/jo048333s
日期:2005.2.1
used for asymmetric hydrogenation of aromatic ketones in a highly enantioselective manner with complete conversion. With 0.1% catalyst loading, complete conversion and enantioselectivity greater than 99% were obtained for most of the aromatic ketones examined. These Ru catalysts thus gave the highest ee for asymmetric hydrogenation of aromatic ketones among all of the catalysts reported in the literature
合成4,4'-取代的xylBINAP家族,并通过NMR光谱和质谱进行表征。的Ru(二膦)(二胺)氯2种基于这些4,4'-取代xylBINAPs和手性二胺(DPEN和DAIPEN)复合物由治疗[(苯)的RuCl的合成2 ] 2与4,4'-取代的- xylBINAP,然后是手性二胺,特征在于1 H和31P NMR光谱和质谱。这些Ru配合物以高度对映选择性的方式用于芳香酮的不对称加氢,并具有完全的转化率。在催化剂负载量为0.1%的情况下,大多数所检测的芳族酮均获得了超过99%的完全转化率和对映选择性。因此,在文献中报道的所有催化剂中,这些Ru催化剂为芳族酮的不对称氢化提供了最高的ee。Ru [(R)-L 4 ] [(R,R)-DPEN] Cl 2的单晶X射线衍射研究表示萘环的4-甲基和两个二甲苯基部分的甲基在Ru中心的DPEN配体的相反侧形成栅栏。这三个甲基与处于不利过渡态的氢键合芳族酮的庞大芳