Brønsted Acid-Catalyzed, Highly Enantioselective Addition of Enamides to In Situ<i>-</i>Generated<i>ortho</i>-Quinone Methides: A Domino Approach to Complex Acetamidotetrahydroxanthenes
作者:Satyajit Saha、Christoph Schneider
DOI:10.1002/chem.201406044
日期:2015.2.2
The highly enantioselective conjugate addition of enamides and enecarbamates to in situ‐generated ortho‐quinone methides, upon subsequent N,O‐acetalization, gives rise to acetamido‐substituted tetrahydroxanthenes with generally excellent enantio‐ and diastereoselectivities. A chiral BINOL‐based phosphoric acid catalyst controls the enantioselectivity of the carbon–carbon bond‐forming event. The products
在随后的N,O-乙缩醛化反应中,将烯酰胺和烯氨基甲酸酯高度对映体选择性共轭加成到原位生成的邻苯二甲rise基甲烷中,生成对乙酰氨基取代的四氢氧杂蒽,它们通常具有出色的对映体和非对映体选择性。基于手性BINOL的磷酸催化剂控制碳-碳键形成事件的对映选择性。产物很容易转化为其他基于x吨的杂环。