Asymmetric Hydrogenation of Aromatic Ketones Catalyzed by the TolBINAP/DMAPEN−Ruthenium(II) Complex: A Significant Effect of <i>N</i>-Substituents of Chiral 1,2-Diamine Ligands on Enantioselectivity
作者:Hirohito Ooka、Noriyoshi Arai、Keita Azuma、Nobuhito Kurono、Takeshi Ohkuma
DOI:10.1021/jo801863q
日期:2008.11.21
mode of enantioface selection was interpreted by using transition state models based on the X-ray structure of the catalyst precursor. The chiral catalyst effected the hydrogenation of alkyl aryl ketones and arylglyoxal dialkyl acetals to afford the chiral alcohol in >99% ee in the best cases. Hydrogenation of racemic benzoin methyl ether with the chiral catalyst through dynamic kinetic resolution gave
研究了在TolBINAP和一系列手性1,2-二胺协同作用的Ru(II)催化剂存在下苯乙酮的不对称加氢反应。对映选择性的意义和程度高度依赖于二胺配体的N-取代基。详细讨论了N取代基的作用。在这些催化剂中,(S)-TolBINAP /(R)-DMAPEN-Ru(II)配合物显示出最高的对映选择性。通过使用基于催化剂前体的X射线结构的过渡态模型来解释对映体选择的模式。在最佳情况下,手性催化剂实现了烷基芳基酮和芳基乙二醛二烷基乙缩醛的加氢,从而提供了> 99%ee的手性醇。通过动态动力学拆分,用手性催化剂将外消旋安息香甲基醚加氢,得到抗醇(syn:anti = 3: