Dioxygen-Triggered Transannular Dearomatization of Benzo[5]helicene Diols: Highly Efficient Synthesis of Chiral π-Extended Diones
作者:Yun Shen、Hai-Yan Lu、Chuan-Feng Chen
DOI:10.1002/anie.201400486
日期:2014.4.25
friendly, readily available (air), and easy to handle, are rather limited. Helicene diols can undergo transannular dearomatization triggered by dioxygen to give diones in quantitative yields within several minutes. By virtue of this, the chirality is successfully transferred from helicity to central chirality to form distorted π‐extended diones having two all‐carbon quaternary stereocenters. The optical resolution
氧化脱芳香化作用是有机合成中的有力策略。然而,关于使用双氧作为氧化剂的报道非常有限,因为它是环境友好的,容易获得的(空气)并且易于处理。螺旋烯二醇可在数分钟内经历由双氧引发的跨环脱芳香化作用,从而以定量收率得到二酮。由此,手性成功地从螺旋性转移到中心手性,形成了具有两个全碳四元立体中心的扭曲的π扩展二酮。通过柱色谱获得光学分辨率,并通过X射线分析确定手性二酮的结构和绝对构型。