Multifunctional Catalysts in the Asymmetric Mannich Reaction of Malononitrile with <i>N</i>-Phosphinoylimines: Coactivation by Halogen Bonding versus Hydrogen Bonding
作者:Kadri Kriis、Harry Martõnov、Annette Miller、Kristin Erkman、Ivar Järving、Mikk Kaasik、Tõnis Kanger
DOI:10.1021/acs.joc.2c00674
日期:2022.6.3
enantioselective Mannich reaction between malononitrile and diphenylphosphinoyl-protected aldimine affording products in high yields (up to 98%) and moderate to high enantiomeric purities (ee up to 89%). Typically, noncovalent catalysts rely on several weak interactions to activate the substrate, with one or two of these giving the most notable contribution to activation. In this instance, instead of the
开发了一种包含卤素键供体、氢键供体和路易斯碱性位点的多功能(非共价)催化剂,并将其应用于丙二腈和二苯基膦酰基保护的醛亚胺之间的对映选择性曼尼希反应,以高收率(高达 98%)和中等对映体纯度高(ee 高达 89%)。通常,非共价催化剂依赖于几种弱相互作用来活化底物,其中一种或两种对活化的贡献最为显着。在这种情况下,不是最初提出的通过卤素键进行的共活化,而是表明氢键在确定对映选择性方面起着关键作用。