Palladium-Catalyzed Chelation-Assisted Aromatic C–H Nitration: Regiospecific Synthesis of Nitroarenes Free from the Effect of the Orientation Rules
作者:Wei Zhang、Shaojie Lou、Yunkui Liu、Zhenyuan Xu
DOI:10.1021/jo400594j
日期:2013.6.21
ortho-nitration of aryl C–H bond is described. A range of azaarenes such as 2-arylquinoxalines, pyridines, quinoline, and pyrazoles were nitrated with excellent chemo- and regioselectivity. Using the O-methyl oximyl group as a removable directing group, the regiospecific synthesis of a variety of o-nitro aryl ketones was achieved starting from aryl ketones via a three-step process involving the Pd-catalyzed
描述了钯催化的螯合辅助芳基CH键的邻位硝化反应。一系列氮杂芳烃(例如2-芳基喹喔啉,吡啶,喹啉和吡唑)被硝化,具有出色的化学和区域选择性。使用ø -甲基肟基团为一个可移动定向基团,各种的区域专一性合成ø硝基芳基酮经由涉及三个步骤的方法来实现从开始芳基酮Pd催化的本位C-H键的-nitration作为关键步骤。机理研究支持在氧化条件下涉及Pd((II / III)和/或Pd(II / IV)催化循环的银介导的自由基机理。