Three-Component Reaction of 3,3-Difluorocyclopropenes, s-Tetrazines, and (benzo) Pyridines

Autor:	Ilya V. Nechaev, Nikolay V. Boev, Georgij V. Cherkaev, Pavel N. Solyev
Rok vydání:	2020
Předmět:	Reaction mechanism 010405 organic chemistry Chemistry Organic Chemistry 010402 general chemistry 01 natural sciences Medicinal chemistry Cycloaddition 0104 chemical sciences chemistry.chemical_compound Tetrazine Functional group Pyridine Reactivity (chemistry) Phenols Stoichiometry
Zdroj:	The Journal of Organic Chemistry. 86:1037-1052
ISSN:	1520-6904 0022-3263
Popis:	A new three-component reaction leading to 1-α-(pyridyl-2-[1,2,4]triazolyl)-2-alkyl-ethanones has been discovered while studying the reactivity of monosubstituted 3,3-difluorocyclopropenes in an inverse electronic demand Diels-Alder (IEDDA) cycloaddition-cycloreversion sequence with s-tetrazines. The reaction involving the above-mentioned reactants and (benzo)pyridine as a third component results in a complex transformation proceeding in mild conditions in a stoichiometric ratio of reactants and has high functional group tolerance (phenols, amides, ethers, carboxylic acids, ketones, and acrylic esters). As a result, simple pyridines are selectively functionalized at the α-position in good isolated yields. The reaction mechanism includes a rare azaphilic [4 + 2]-cycloaddition step between s-tetrazine and intermediate 1-hydroxyindolizine, suggested after byproduct identification and tracked with a deuterium label. To date, it is only the third known example of skewed azaphilic cycloaddition of tetrazine. The reaction is truly three-component and cannot be effectively performed stepwise.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::3c79e4b1aaa9266740a3fdb0b39b343f https://doi.org/10.1021/acs.joc.0c02292 Zobrazit plný text záznamu