Asymmetric Reactions Catalyzed by Chiral Metal Complex. LIX. Preparations of Chiral Pyrrolidinebisphosphines Bearing Two Different Types of Phosphino Groups and Their Use in Efficient Catalytic Asymmetric Hydrogenation.
作者:Toshiaki MORIMOTO、Hisashi TAKAHASHI、Kazuo ACHIWA
DOI:10.1248/cpb.42.481
日期:——
Chiral pyrrolidinebisphosphine ligands, (2S-cis)-BCPM and (2S-cis)-BCPP, bearing two different types of phosphino groups, a dicyclohexylphosphino group and a diphenylphosphino groups, were designed and prepared on the basis of our design concept for developing highly efficient ligands. The validity of the concept was confirmed experimentally in the asymmetric hydrogenation of ketopantolactone using neutral rhodium(I) complexes of BCPM, BCPP, BPPM, and BCCP. The rhodium(I) complex of (2S-cis)-BCPM was found to be the most effective catalyst (substrate/catalyst >ca. 104, >90%ee (R)).
手性吡咯烷双磷配体(2S-cis)-BCPM 和(2S-cis)-BCPP,分别具有两种不同类型的磷基团:双环己基磷基团和二苯基磷基团,基于我们开发高效配体的设计理念进行了设计和制备。通过使用BCPM、BCPP、BPPM和BCCP的中性铑(I)配合物,在酮氨基酸内酯的非对称加氢反应中实验验证了该设计理念的有效性。研究发现(2S-cis)-BCPM的铑(I)配合物是最有效的催化剂(底物/催化剂 >约104,>90%酯选窗率 (R))。