title: Synthesis of Indeno[1',2':4,5]imidazo[1,2-a]pyridin-11-ones and Chromeno[4',3':4,5]imidazo[1,2-a]pyridin-6-ones through Palladium-Catalyzed Cascade Reactions of 2-(2-Bromophenyl)imidazo[1,2-a]pyridines.
abstract: A novel and efficient synthesis of 11H-indeno[1',2':4,5]imidazo[1,2-a]pyridin-11-one, a hybrid structure of indenone with imidazo[1,2-a]pyridine, from the reaction of 2-(2-bromophenyl)imidazo[1,2-a]pyridine with carbon monoxide through palladium-catalyzed CO insertion and C-H bond activation, has been developed. Intriguingly, under similar conditions but in the presence of Cu(OAc)2, the reaction selectively afforded 6H-chromeno[4',3':4,5]imidazo[1,2-a]pyridin-6-one, a hybrid structure of chromenone with imidazo[1,2-a]pyridine, via a more sophisticated cascade process including acetoxylation, deacetylation, CO insertion, and C-H bond activation.
authors.affiliation: School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University , Xinxiang, Henan 453007, China.
authors.forename: Ju
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University , Xinxiang, Henan 453007, China.
authors.forename: Xinying
authors.initials: X
authors.lastname: Zhang
authors.affiliation: School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University , Xinxiang, Henan 453007, China.
authors.forename: Xuesen
authors.initials: X
authors.lastname: Fan