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 |
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| Authors: | Huimin Liu QiongMei Zhang Limin Wang Prof?Dr Xiaofeng Tong Dr |
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| Institution: | Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Meilong Road 130, Shanghai, 200237 (P.R. China), Fax: (+86)?21‐64253881 |
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| Abstract: | A new PPh3‐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. |
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| Keywords: | hydrogen transfer imines phosphanes reaction mechanisms zwitterions |
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