Collaborative Innovation Center of New Drug Research and Safety Evaluation, Henan Province, School of Pharmaceutical Sciences, and College of Chemistry and Molecular Engineering, and ‡Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University , Zhengzhou 450001, China.
Org Lett. 2016 Oct 7;18(19):5022-5025. doi: 10.1021/acs.orglett.6b02480. Epub 2016 Sep 21.
A highly torquoselective process for simultaneous control of central and axial chirality by the annulation of terminally substituted ynamides with o-quinone methides is reported. In the presence of AlCl, a sequence comprising a [2 + 2] cycloaddition followed by the torquoselective 4π-electrocyclic ring opening and 6π-electrocyclic ring closure leads to highly stereoselective formation of diastereoisomeric 4-amino-2H-chromenes. Terminally unsubstituted ynamides undergo AlCl-catalyzed [4 + 2] cycloaddition with o-quinone methides providing 2-amino-4H-chromenes.
报道了一种通过末端取代的炔酰胺与邻醌甲醚的环化反应来高对映选择性地同时控制中心和轴向手性的方法。在 AlCl 的存在下，一个包括[2 + 2]环加成反应和随后的对映选择性 4π-电环开环和 6π-电环闭环反应的序列导致高度立体选择性地形成非对映异构体 4-氨基-2H-色烯。末端未取代的炔酰胺与邻醌甲醚在 AlCl 催化下发生[4 + 2]环加成反应，生成 2-氨基-4H-色烯。
