Key Laboratory of Synthetic Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry (CAS), 345 Lingling Road, Shanghai, 200032, China.
University of the Chinese Academy of Sciences, 19A Yuquan Road, Beijing, 100049, China.
Angew Chem Int Ed Engl. 2017 Sep 11;56(38):11599-11603. doi: 10.1002/anie.201706018. Epub 2017 Aug 9.
A type II nitroso-ene cyclization was developed for the construction of morphan derivatives with good functional-group tolerance. DFT calculations revealed that the nitroso-ene reaction proceeds in a stepwise manner involving diradical or zwitterionic intermediates. The rate-determining step is C-N bond formation, followed by a rapid hydrogen-transfer step with a chair-conformation transition state. The current approach was also successfully applied in the first total synthesis of (±)-kopsone, a highly strained yet simple morphan-type alkaloid isolated from Kopsia macrophylla.
一种 II 型亚硝-烯环化反应被开发出来，用于构建具有良好官能团耐受性的吗啡衍生物。DFT 计算表明，亚硝-烯反应是分步进行的，涉及自由基或两性离子中间体。速率决定步骤是 C-N 键的形成，随后是快速的氢转移步骤，具有椅式构象过渡态。该方法还成功地应用于首次全合成（±）-kopsoone，这是一种从大苞钩麻中分离出来的高度应变但简单的吗啡型生物碱。
