McConnell, Danielle L.; Blades, Alisha M.; Rodrigues, Danielle Gomes; Keyes, Phoebe V.; Sonberg, Justin C.; Anthony, Caitlin E.; Rachad, Sofia; Simone, Olivia M.; Sullivan, Caroline F.; Shapiro, Jonathan D.; Williams, Christopher C.; Schafer, Benjamin C.; Glanzer, Amy M.; Hutchinson, Holly L.; Thayaparan, Ashley B.; Krevlin, Zoe A.; Bote, Isabella C.; Haffary, Yasin A.; Bhandari, Sambat; Goodman, Jack A.; Majireck, Max M. published an article in 2021. The article was titled 《Synthesis of Bench-Stable N-Quaternized Ketene N,O-Acetals and Preliminary Evaluation as Reagents in Organic Synthesis》, and you may find the article in Journal of Organic Chemistry.Category: pyridine-derivatives The information in the text is summarized as follows:
In this report, a general synthetic approach to a variety of bench-stable N-quaternized ketene N,O-acetals I (R = H, 2-Ph, 4-Me, 2,6-Cl2, etc.; X = OTf, NTf2) via treatment of pyridine II or aniline bases with acetylenic ethers R1CC (R1 = OEt, 4-methoxyphenyl) and an appropriate Bronsted or Lewis acid (triflic acid, triflimide, or scandium(III) triflate) have been described. The resulting pyridinium I and anilinium salts C6H5N+((CH3)CH2)C(=CH2)R1 X- can be used as reagents or synthetic intermediates in multiple reaction types. For example, N-(1-ethoxyvinyl)pyridinium or anilinium salts can thermally release highly reactive O-Et ketenium ions for use in acid catalyst-free electrophilic aromatic substitutions. N-(1-ethoxyvinyl)-2-halopyridinium salts I (R = 2-Cl, 2-Br) can be employed in peptide couplings as a derivative of Mukaiyama reagent (2-chloro-1-methylpyridinium iodide) or react with phenylmethanamine in nucleophilic aromatic substitutions under mild conditions. These preliminary reactions illustrate the broad potential of these currently understudied compounds in organic synthesis. In the experiment, the researchers used many compounds, for example, 2,6-Dibromopyridine(cas: 626-05-1Category: pyridine-derivatives)
2,6-Dibromopyridine(cas: 626-05-1) belongs to pyridine. Pyridine is very deactivated towards electrophilic substitution with respect to benzene. For this reason classical formylation, using methods such as the Gattermann or Vilsmeier reactions, are not generally successful. Category: pyridine-derivatives