Sequential Phosphine-Catalyzed [4 + 2] Annulation of β′-Acetoxy Allenoates: Enantioselective Synthesis of 3-Ethynyl-Substituted Tetrahydroquinolines
作者:Qinglong Zhang、Hongxing Jin、Jiaxu Feng、Yannan Zhu、Penghao Jia、Chengzhou Wu、You Huang
DOI:10.1021/acs.orglett.9b00130
日期:2019.3.1
The first enantioselective sequential phosphine-catalyzed (SPC as abbreviation) mode for the formation of tetrahydroquinolines with an ethynyl-substituted all-carbon quaternary stereogenic center is reported. In this SPC process, a novel [4 + 2] annulation process was devised employing α-substituted allenoates as C2 synthons (α–β′, 1,2-dipole) for the first time. 3-Ethynyl-substituted tetrahydroquinolines
报道了具有乙炔基取代的全碳季立体中心的四氢喹啉形成的第一个对映选择性连续膦催化(SPC为缩写)模式。在此SPC工艺中,首次设计了一种新颖的[4 + 2]环空工艺,该工艺采用α-取代的烯丙酸酯作为C2合成子(α-β',1,2-偶极子)。3-乙炔基取代的四氢喹啉很容易以高收率和高对映选择性制备。