Combined organo- and gold-catalyzed enantioselective synthesis of bicyclic enones
作者:Theo Zweifel、Dirk Hollmann、Birgit Prüger、Martin Nielsen、Karl Anker Jørgensen
DOI:10.1016/j.tetasy.2010.05.044
日期:2010.6
gold catalysis highly enantioenriched bicyclic enones are available via an operationally simple one-pot procedure. Iminium-ion activation by cinchona alkaloid-derived primary amine catalysts induces the Michael addition of propargylated malononitriles and cyanoacetates to α,β-unsaturated ketones. The resulting intermediates undergo an exo-dig cyclization, forming a new C–C bond followed by double-bond
通过有机催化与金催化的结合,可通过操作简单的一锅法获得高度对映体富集的双环烯酮。金鸡纳生物碱衍生的伯胺催化剂对亚胺离子的活化作用,将炔丙基化丙二腈和氰基乙酸酯的迈克尔加成至α,β-不饱和酮上。生成的中间体经过exo-dig环化反应,形成新的C-C键,然后进行双键异构化,从而以高收率和高对映选择性提供高度官能化的双环烯酮。