Meta-selective CAr-H nitration of arenes through a Ru3(CO)12-catalyzed ortho-metalation strategy was written by Fan, Zhoulong;Ni, Jiabin;Zhang, Ao. And the article was included in Journal of the American Chemical Society in 2016.Electric Literature of C12H11N This article mentions the following:
The first example of transition metal-catalyzed meta-selective CAr-H nitration of arenes, substituted with N-donor directing groups, such as 2-phenylpyridines, is described. With the use of Ru3(CO)12 as the catalyst and Cu(NO3)2·3H2O as the nitro source, a wide spectrum of arenes bearing diversified N-heterocycles or oximido as the directing groups were nitrated with meta-selectivity exclusively. Mechanism studies have demonstrated the formation of a new 18e-octahedral ruthenium species as a key ortho-CAr-H metalated intermediate, which may be responsible for the subsequent meta-selective electrophilic aromatic substitution (SEAr). Moreover, this approach provides a fast-track strategy for atom/step economical synthesis of many useful pharmaceutical mols. In the experiment, the researchers used many compounds, for example, 2-(m-Tolyl)pyridine (cas: 4373-61-9Electric Literature of C12H11N).
2-(m-Tolyl)pyridine (cas: 4373-61-9) belongs to pyridine derivatives. Pyridine’s the lone pair does not contribute to the aromatic system but importantly influences the chemical properties of pyridine, as it easily supports bond formation via an electrophilic attack. Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.Electric Literature of C12H11N