Trost Barry M, Gnanamani Elumalai, Hung Chao-I Joey, Kalnmals Christopher A
Department of Chemistry , Stanford University , Stanford , California 94305 , United States.
Org Lett. 2019 Mar 15;21(6):1890-1894. doi: 10.1021/acs.orglett.9b00496. Epub 2019 Mar 4.
Densely substituted chiral pyrrolidones are synthesized via phosphine-catalyzed cycloisomerization of enantioenriched β-amino ynones, which are prepared in a single step using a highly enantioselective Zn-ProPhenol-catalyzed Mannich reaction. The exocyclic alkenes in the cyclization products provide versatile handles for further transformations and typically form with good E/ Z selectivity. This cycloisomerization method can be performed in streamlined fashion, without purification of the intermediate Mannich adduct, and extends to anthranilic acid based scaffolds in addition to ProPhenol-derived Mannich adducts.
通过膦催化对映体富集的β-氨基烯炔酮的环异构化反应合成了高度取代的手性吡咯烷酮，其中β-氨基烯炔酮是使用高度对映选择性的锌-脯氨醇催化的曼尼希反应一步制备的。环化产物中的环外烯烃为进一步转化提供了通用的操作基团，并且通常以良好的E/Z选择性形成。这种环异构化方法可以以简化的方式进行，无需纯化中间曼尼希加合物，并且除了脯氨醇衍生的曼尼希加合物之外，还适用于基于邻氨基苯甲酸的支架。
