Diastereo- and Enantioselective Catalytic Radical Oxysulfonylation of Alkenes in β,γ-Unsaturated Ketoximes
作者:Xi-Tao Li、Ling Lv、Ting Wang、Qiang-Shuai Gu、Guo-Xing Xu、Zhong-Liang Li、Liu Ye、Xinhao Zhang、Gui-Juan Cheng、Xin-Yuan Liu
DOI:10.1016/j.chempr.2020.03.024
日期:2020.7
The asymmetric radical-initiated difunctionalization of internal alkenes, which creates two vicinal stereocenters, has been a significant synthetic challenge despite the tremendous progress achieved for terminal alkenes. This is attributable to the common stepwise mechanism that involves an initial free radical addition to the alkene in a nonstereoselective fashion. We report here the first asymmetric
尽管末端烯烃取得了巨大进展,但内部烯烃的不对称自由基引发的双官能化(产生两个邻位立体中心)一直是一项重大的合成挑战。这归因于通常的逐步机理,该机理涉及以非立体选择性方式将初始自由基加成至烯烃。在铜(I)-金鸡纳生物碱基磺酰胺催化剂存在下,我们在这里报告了β,γ-不饱和酮肟中末端和内部芳基烯烃的第一个不对称自由基1,2-氧磺酰化。实验和计算机制研究共同支持Cu II -Cu I这种机制的特点是将磺酰基快速,可逆地加成到烯烃上,并随后由速率和立体决定C-O键的形成,即在Curtin-Hammett动力学控制下的情况。该方法为各种有价值的手性含磺酰基的结构单元的各种阵列的集体合成提供了鲁棒的平台。