Redox-Neutral [4 + 2] Annulation of <i>N</i>-Methoxybenzamides with Alkynes Enabled by an Osmium(II)/HOAc Catalytic System
作者:Jian Yang、Liexin Wu、Huiying Xu、Hui Gao、Zhi Zhou、Wei Yi
DOI:10.1021/acs.orglett.9b03827
日期:2019.12.20
C-H activation strategy, an efficient osmium(II)-catalyzed redox-neutral [4 + 2] annulation of N-methoxybenzamides with alkynes has been accomplished. Computational and experimental studies revealed that such transformation leading to the synthesis of the isoquinolone core might follow an Os(II)-Os(IV)-Os(II) catalytic pathway, in which an unusual HOAc-assisted oxidative addition of osmium(II) into
通过使用直接的CH活化策略,已实现了有效的(II)催化的炔烃与N-甲氧基苯甲酰胺的氧化还原中性[4 + 2]环化反应。计算和实验研究表明,这种导致异喹诺酮核心合成的转变可能遵循Os(II)-Os(IV)-Os(II)催化途径,其中不寻常的HOAc辅助氧化addition(II)进入NO键生成generate(IV)物种是关键的过渡态之一。对于其他线性或环状产物的一锅法组装,也已举例说明了由(II)催化剂实现的不同的CH活化反应模式的进一步探索。