title: PPh3-catalyzed reactions of alkyl propiolates with N-tosylimines: a facile synthesis of alkyl 2-[aryl(tosylimino)methyl]acrylate and an insight into the reaction mechanism.
abstract: A new PPh(3)-catalyzed synthesis of alkyl 2-[aryl(tosylimino)methyl]acrylates from propiolate and N-tosylimine has been developed. Deuterium-labelling experiments show that the reaction mechanism involves several hydrogen-transfer processes, which are not the turnover-limiting step and strongly rely on the nature of the reaction media. The stable phosphonium-enamine zwitterion, which was proven to play an important role in the catalytic cycle, has been isolated and characterised by X-ray analysis.
authors.affiliation: Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Meilong Road 130, Shanghai, 200237, PR China.
authors.forename: Huimin
authors.initials: H
authors.lastname: Liu
authors.forename: QiongMei
authors.initials: Q
authors.lastname: Zhang
authors.forename: Limin
authors.initials: L
authors.lastname: Wang
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Tong