Stereoselective Palladium‐Catalyzed C−F Bond Alkynylation of Tetrasubstituted gem‐Difluoroalkenes |
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Authors: | Qiao Ma Yanhui Wang Gavin Chit Tsui |
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Abstract: | A stereoselective Pd(PPh3)4‐catalyzed C?F bond alkynylation of tetrasubstituted gem‐difluoroalkenes with terminal alkynes has been developed. This method gives access to a great variety of conjugated monofluoroenynes bearing a tetrasubstituted alkene moiety with well‐defined stereochemistry. Chelation‐assisted oxidative addition of Pd to the C?F bond is proposed to account for the high level of stereocontrol. An X‐ray crystal structure of a key monofluorovinyl PdII intermediate has been obtained for the first time as evidence for the proposed mechanism. |
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Keywords: | C− F bonds fluoroalkenes fluoroenynes oxidative addition palladium |
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