One-Step Synthesis of β-Alkylidene-γ-lactones via Ligand-Enabled β,γ-Dehydrogenation of Aliphatic Acids was written by Sheng, Tao;Zhuang, Zhe;Wang, Zhen;Hu, Liang;Herron, Alastair N.;Qiao, Jennifer X.;Yu, Jin-Quan. And the article was included in Journal of the American Chemical Society in 2022.HPLC of Formula: 315180-16-6 This article mentions the following:
Ligand-enabled Pd-catalyzed regioselective α,β-dehydrogenation of carbonyl compounds via β-methylene C-H activation has recently emerged as a promising transformation. Herein, authors report the realization of β,γ-dehydrogenation and subsequent vinyl C-H olefination reactions of free carboxylic acids, thus providing a unique method for the structural diversification of aliphatic acids containing α-quaternary centers through sequential functionalizations of two β-C-H bonds and one γ-C-H bond. This tandem dehydrogenation-olefination-lactonization reaction offers a one-step preparation of β-alkylidene-γ-lactones, which are often difficult to prepare through conventional methods, from inexpensive and abundant free aliphatic acids. A variety of free aliphatic acids, such as isosteviol and grandiflorolic acid natural products, and olefins are compatible with the reported protocol. The newly designed bidentate oxime ether-pyridone and morpholine-pyridone ligands are crucial for this tandem reaction to proceed. Notably, these ligands also enable preferential methylene C-H activation over the previously reported, competing process of Me C-H bond olefination. In the experiment, the researchers used many compounds, for example, 2-(Chloromethyl)-6-fluoropyridine (cas: 315180-16-6HPLC of Formula: 315180-16-6).
2-(Chloromethyl)-6-fluoropyridine (cas: 315180-16-6) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-bonding aromatic system using its unhybridized p orbital. The lone pair is in an sp2 orbital, projecting outward from the ring in the same plane as the σ bonds. Many analogues of pyridine are known where N is replaced by other heteroatoms . Substitution of one C–H in pyridine with a second N gives rise to the diazine heterocycles (C4H4N2), with the names pyridazine, pyrimidine, and pyrazine.HPLC of Formula: 315180-16-6