Palladium-Catalyzed Aromatic C-H Bond Nitration Using Removable Directing Groups: Regiospecific Synthesis of Substituted o-Nitrophenols from Related Phenols was written by Zhang, Wei;Zhang, Jian;Ren, Shaobo;Liu, Yunkui. And the article was included in Journal of Organic Chemistry in 2014.Safety of 2-Phenoxypyridine This article mentions the following:
A general and regiospecific transformation of substituted phenols into the related o-nitrophenols has been achieved via a three-step process involving the palladium-catalyzed chelation-assisted ortho-C-H bond nitration as the key step. In the process, 2-pyridinyloxy groups act as removable directing groups for the palladium-catalyzed ortho-nitration of substituted 2-phenoxypridines, and they can be readily removed in the subsequent conversion of the resulting 2-(2-nitrophenoxy)pyridines into 2-nitrophenols. In the experiment, the researchers used many compounds, for example, 2-Phenoxypyridine (cas: 4783-68-0Safety of 2-Phenoxypyridine).
2-Phenoxypyridine (cas: 4783-68-0) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.Safety of 2-Phenoxypyridine