Department of Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya 466-8555, Japan.
Frontier Research Institute for Material Science, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya 466-8555, Japan.
Org Lett. 2020 Apr 17;22(8):2868-2872. doi: 10.1021/acs.orglett.0c00289. Epub 2020 Feb 12.
The enantioselective vinylogous Mannich reaction of ketimines derived from isatins with acyclic vinylketene silyl acetals has been developed using a chiral bis(imidazoline)-Cu(II) catalyst. A series of chiral 3-aminooxindole derivatives bearing tetra-substituted stereogenic centers with an α,β-unsaturated ester moiety were obtained in excellent yields (up to 99%) with high enantioselectivities (up to 98% ee). Enantioselective bisvinylogous Mannich reaction to ketimines derived from isatins also afforded product with high enantioselectivity. Based on the experimental investigations, a possible transition state has been proposed to explain the origin of the asymmetric induction.
手性双咪唑啉-Cu(II)催化剂的发展实现了靛红衍生的亚胺与环状乙烯基硅基缩醛的对映选择性 vinylogous Mannich 反应。通过该方法，一系列含有α,β-不饱和酯基的手性 3-氨基氧吲哚衍生物以高产率（高达 99%）和高对映选择性（高达 98%ee）得到。靛红衍生的亚胺的对映选择性双 vinylogous Mannich 反应也得到了具有高对映选择性的产物。根据实验研究，提出了一个可能的过渡态来解释不对称诱导的起源。
