Rh(III)-Catalyzed Mild Coupling of Nitrones and Azomethine Imines with Alkylidenecyclopropanes via C–H Activation: Facile Access to Bridged Cycles
作者:Dachang Bai、Teng Xu、Chaorui Ma、Xin Zheng、Bingxian Liu、Fang Xie、Xingwei Li
DOI:10.1021/acscatal.8b00746
日期:2018.5.4
activation of nitrones and azomethine imines in the context of dipolar addition with alkylidenecyclopropanes (ACPs) have been realized. By taking advantage of the ring strain in ACPs, the reaction with aryl nitrones delivered bridged [3.2.1] bicyclic isoxazolidines, and reaction with azomethine imines afforded bridged tricyclic pyrazolones under the same conditions, where both the nitrone and azomethine
桥接循环是各种生物活性分子中重要的一类结构基序。在用亚烷基亚环丙烷(ACP)偶极加成的情况下,Rh(III)催化了硝酮和甲亚胺亚胺的CH活化。通过利用ACP中的环应变,在相同条件下,与芳基亚硝基的反应可提供桥连的[3.2.1]双环异恶唑烷,与偶氮甲亚胺的反应可得到桥连的三环吡唑啉酮,其中硝酮和偶氮甲亚胺都可充当偶极指导小组。所有反应均在温和条件下发生,底物范围广,效率高且非对映选择性> 20:1。该协议的综合应用也得到了证明。