Metal-Free Synthesis of C-4 Substituted Pyridine Derivatives Using Pyridine-boryl Radicals via a Radical Addition/Coupling Mechanism: A Combined Computational and Experimental Study was written by Wang, Guoqiang;Cao, Jia;Gao, Liuzhou;Chen, Wenxin;Huang, Wenhao;Cheng, Xu;Li, Shuhua. And the article was included in Journal of the American Chemical Society in 2017.Formula: C6H3FN2 This article mentions the following:
D. functional theory investigations revealed that the pyridine-boryl radical generated in situ using 4-cyanopyridine and bis(pinacolato)diboron could be used as a bifunctional “reagent”, which serves as not only a pyridine precursor but also a boryl radical. With the unique reactivity of such radicals, 4-substituted pyridine derivatives could be synthesized using α,β-unsaturated ketones and 4-cyanopyridine via a novel radical addition/C-C coupling mechanism. Several controlled experiments were conducted to provide supportive evidence for the proposed mechanism. In addition to enones, the scope could be extended to a wide range of boryl radical acceptors, including various aldehydes and ketones, aryl imines and alkynones. Lastly, this transformation was applied in the late-stage modification of a complicated pharmaceutical mol. In the experiment, the researchers used many compounds, for example, 2-Fluoroisonicotinonitrile (cas: 3939-14-8Formula: C6H3FN2).
2-Fluoroisonicotinonitrile (cas: 3939-14-8) belongs to pyridine derivatives. Pyridine has a conjugated system of six π electrons that are delocalized over the ring. The molecule is planar and, thus, follows the Hückel criteria for aromatic systems. Pyridine groups exist in countless molecules, and their applications include catalysis, drug design, molecular recognition, and natural product synthesis.Formula: C6H3FN2