Iridium‐Catalyzed Hydrogenation of β‐Dehydroamino Acid Derivatives Using Monodentate Phosphoramidites
作者:Stephan Enthaler、Giulia Erre、Kathrin Junge、Kristin Schröder、Daniele Addis、Dirk Michalik、Marko Hapke、Dmitry Redkin、Matthias Beller
DOI:10.1002/ejoc.200800241
日期:2008.7
asymmetric hydrogenation of 13 different β-dehydroamino acid derivatives to give optically active β-amino acid esters has been examined. Readily accessible monodentate octahydrobinaphthol-based phosphoramidites were used as chiral ligands. Good to excellent enantioselectivities and yields were obtained for the E isomers, whereas poorer catalyst performance was found for the Z isomers. Importantly, to obtain
已经研究了铱催化的 13 种不同的 β-脱氢氨基酸衍生物的不对称氢化,以产生具有旋光活性的 β-氨基酸酯。容易获得的基于单齿八氢联萘酚的亚磷酰胺用作手性配体。E 异构体的对映选择性和产率非常好,而 Z 异构体的催化剂性能较差。重要的是,为了获得高对映选择性,必须在配体的 3,3' 位进行取代。在优化条件下实现了高达 94 % ee 的对映选择性。 (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)