Palladium-Catalyzed C–H Bond Activation by Using Iminoquinone as a Directing Group and an Internal Oxidant or a Co-oxidant: Production of Dihydrophenanthridines, Phenanthridines, and Carbazoles
作者:Selvam Raju、Pratheepkumar Annamalai、Pei-Ling Chen、Yi-Hung Liu、Shih-Ching Chuang
DOI:10.1021/acs.orglett.7b01956
日期:2017.8.4
A palladium-catalyzed C–H bond activation reaction, via a redox-neutral pathway, for the preparation of dihydrophenanthridine, phenanthridine, and carbazole derivatives from biaryl 2-iminoquinones is developed. The preinstalled iminoquinone was designed to act as a directing group for ortho C–H activation and an internal oxidant or a co-oxidant. This catalysis proceeded through the following sequence:
通过氧化还原中性途径开发了钯催化的CH键活化反应,用于从联芳基2-亚氨基醌制备二氢菲啶,菲啶和咔唑衍生物。预先安装的亚氨基醌被设计成可作为邻位C–H活化的引导基团和内部氧化剂或助氧化剂。该催化过程按以下顺序进行:C–H键活化,活化烯烃的配位和插入,β-氢化物消除,H-移位,插入和质子化或β-氢化物消除。另外,通过使用该方法可以有效地制备咔唑,而无需添加外部氧化剂。