title: Synthesis of Pyrazolo[5,1-a]isoquinolines and 8-Methylenepyrazolo[5,1-a]isoindoles via Regioselective C-C Coupling and Alkyne Hydroamination.
abstract: An efficient and convenient synthesis of pyrazolo[5,1-a]isoquinolines has been achieved via palladium-catalyzed Sonogashira coupling of terminal alkynes with 5-(2-bromophenyl)-1H-pyrazoles, in situ formed from the condensation of 1-(2-bromophenyl)buta-2,3-dien-1-ones with hydrazine hydrate, followed by 6-endo intramolecular alkyne hydroamination. More interestingly, 8-methylenepyrazolo[5,1-a]isoindoles, the regioisomer of pyrazolo[5,1-a]isoquinolines, could also be selectively synthesized from the same starting materials through an initial intermolecular hydroamination of terminal alkynes with 5-(2-bromophenyl)-1H-pyrazoles followed by a palladium-catalyzed 5-exo intramolecular Heck coupling reaction.
authors.affiliation: School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Henan Key Laboratory of Green Chemical Media and Reactions, 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
authors.affiliation: School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Henan Key Laboratory of Green Chemical Media and Reactions, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University , Xinxiang, Henan 453007, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Yan
authors.affiliation: School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Henan Key Laboratory of Green Chemical Media and Reactions, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University , Xinxiang, Henan 453007, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Henan Key Laboratory of Green Chemical Media and Reactions, 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