Highly Selective Asymmetric Hydrogenation Using a Three Hindered Quadrant Bisphosphine Rhodium Catalyst
作者:Garrett Hoge、He-Ping Wu、William S. Kissel、Derek A. Pflum、Derek J. Greene、Jian Bao
DOI:10.1021/ja048496y
日期:2004.5.1
synthesis of both enantiomers of ligand 2 and rhodium complex 5 is presented. The crux of the synthesis is a chiral HPLC separation of the enantiomers of 4. Rhodium complex 5 possesses three hindered quadrants in the steric environment within which a substrate binds. Evidence is presented that this configuration leads to high enantioselectivity (>99% ee) for rhodium-catalyzed asymmetric hydrogenation of
介绍了配体 2 和铑配合物 5 的对映异构体的简明合成。合成的关键是 4 的对映异构体的手性 HPLC 分离。铑配合物 5 在底物结合的空间环境中具有三个受阻象限。有证据表明,对于铑催化的 α-乙酰氨基脱氢氨基酸 6a-e 的不对称氢化,这种配置导致高对映选择性(> 99% ee)。还报道了高对映选择性用于药物候选物普瑞巴林的底物前体 8 的氢化。讨论了使用催化剂 5a 与 Rh-Me-DuPhos 对 8 进行大规模加氢的优势。