Palladium-Catalyzed Cyclization of Alkynoic Acids To Form Vinyl Dioxanones Bearing a Quaternary Allylic Carbon
作者:Yohei Ogiwara、Kazuya Sato、Norio Sakai
DOI:10.1021/acs.orglett.7b02572
日期:2017.10.6
A palladium-catalyzed intramolecular reaction of carboxylic acids and alkynes in a novel cyclization manner was developed. This unique cyclization efficiently provided a wide range of complex ring systems—vinyl dioxanones bearing a quaternary allylic carbon. Mechanistic studies suggest an allenyl carboxylate as an intermediate.
The unique cyclization of benzamide derivatives that contain an alkyne by a Pd(0)/dialkyl(biaryl)phosphine catalytic system is reported. The reaction efficiently provides a variety of six-membered N-heterocyclic compounds that contain a fully substituted carbon center without the need for a stoichiometric additive. Mechanistic studies suggest that this unprecedented cyclization starts with the cleavage