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Updated: Mar 3, 2026

Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
Published on: June 21, 2017
Enantioselective Silver and Amine Co-catalyzed Desymmetrizing Cycloisomerization of Alkyne-Linked Cyclohexanones
Rubén Manzano1, Swarup Datta1, Robert S Paton1
1Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK.
Abstract:
A silver(I) and amine co-catalyzed desymmetrization of 4-propargylamino cyclohexanones for the direct enantioselective synthesis of 2-azabicyclo[3.3.1]nonanes is described. Exploiting reactivity arising from dual activation of the pendant terminal alkyne by silver(I) and the ketone moiety through transient enamine formation, this synthetically relevant transformation is easy to perform, efficient and broad in scope. High enantioselectivity (up to 96 % ee) was achieved by exploiting a significant matching effect between the chirality of a cinchona alkaloid-derived aminophosphine ligand for the silver(I) salt and the 2-bis(aryl)methylpyrrolidine catalyst which was rationalized by DFT calculations. This allowed for the preparation of both enantiomers of the bicyclic product with near-identical stereocontrol.
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