Department of Chemistry, National Tsing-Hua University, Hsinchu, Taiwan.
Angew Chem Int Ed Engl. 2017 Feb 13;56(8):2035-2039. doi: 10.1002/anie.201611388. Epub 2017 Jan 16.
One-pot cascade annulations among nitrosoarenes, alkenes, and N-hydroxyallylamines have been achieved with CuCl/O catalysts, forming fused oxazinane/isoxazolidine heterocycles with excellent diastereoselectivity (d.r. >20:1). To enhance the synthetic utility, we developed a successive cleavage of the two N-O bonds of the resulting heterocycles. A mechanism involving dipolar [3+2] cycloadditions of nitrone intermediates with their tethered alkenes is postulated for formation of these heterocycles.
一锅法硝酮、烯烃和 N-羟丙基酰胺的级联环化反应在 CuCl/O 催化剂作用下实现，形成具有优异非对映选择性（d.r. >20:1）的稠合噁嗪烷/异噁唑烷杂环。为了增强合成实用性，我们开发了对生成的杂环的两个 N-O 键的连续断裂。假定了涉及氮氧自由基中间体与它们连接的烯烃的偶极[3+2]环加成反应来形成这些杂环。
