Primary Amine Attached to an<i>N</i>-(Carboxyalkyl)imidazolium Cation: A Recyclable Organocatalyst for the Asymmetric Michael Reaction
作者:Alexandr S. Kucherenko、Vladislav G. Lisnyak、Alexandr O. Chizhov、Sergei G. Zlotin
DOI:10.1002/ejoc.201400045
日期:2014.6
2S)-1,2-diphenylethane-1,2-diamine derivative modified with an N-(4-carboxybutyl)imidazolium cation and PF6– anion has been developed and applied as a recyclable organocatalyst of the asymmetric 1,4-conjugate addition of 4-hydroxy-2H-chromen-2-one to 1-substituted buten-3-ones or cyclohexen-3-one to afford corresponding Michael adducts in high yields (up to 97 %) and enantioselectivities (up to 90 % ee)
已开发出用 N-(4-羧基丁基)咪唑鎓阳离子和 PF6– 阴离子改性的 (1S,2S)-1,2-二苯基乙烷-1,2-二胺衍生物,并将其用作不对称 1,4 的可回收有机催化剂- 4-羟基-2H-色烯-2-酮与1-取代丁烯-3-酮或环己烯-3-酮的共轭加成以高产率(高达97%)和对映选择性(高达90%)提供相应的迈克尔加合物% ee)。临床上有用的抗凝剂华法林的活性最强的(S)对映体就是这样制备的。与不含羧基的已知类似物相比,该催化剂表现出更好的可回收性:它可以在反应中循环 5 次,而不会显着降低产品收率或 ee 值。