Regiospecific Synthesis of Nitroarenes by Palladium-Catalyzed Nitrogen-Donor-Directed Aromatic CH Nitration
作者:Yun-Kui Liu、Shao-Jie Lou、Dan-Qian Xu、Zhen-Yuan Xu
DOI:10.1002/chem.201002581
日期:2010.12.10
Nitration of N‐heteroaromatics: The first example of palladium‐catalyzed direct ortho‐nitration of aryl CH bonds is described. A range of azaarenes, such as 2‐arylquinoxalines, pyridines, pyrazoles, and O‐methyl oximes, were nitrated with excellent chemo‐ and regioselectivity (see scheme; DCE=1,2‐dichloroethane). Preliminary mechanistic investigations support a silver‐mediated radical mechanism involving
的N-杂芳族化合物的硝化:钯催化的直接的第一个例子邻芳基C的-nitration H键进行说明。一系列氮杂芳烃,例如2-芳基喹喔啉,吡啶,吡唑和O-甲基肟被硝化,具有出色的化学和区域选择性(参见方案; DCE = 1,2-二氯乙烷)。初步的机理研究支持在氧化条件下涉及钯(II / III)和/或钯(II / IV)催化循环的银介导的自由基机理。