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Updated: Jun 19, 2026

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
5(6)-anti-Substituted-2-azabicyclo[2.1.1]hexanes: a nucleophilic displacement route
Grant R Krow1, Ram Edupuganti, Deepa Gandla
1Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA. grkrow@temple.edu
Abstract:
Nucleophilic displacements of 5(6)-anti-bromo substituents in 2-azabicyclo[2.1.1]hexanes (methanopyrrolidines) have been accomplished. These displacements have produced 5-anti-X-6-anti-Y-difunctionalized-2-azabicyclo[2.1.1]hexanes containing bromo, fluoro, acetoxy, hydroxy, azido, imidazole, thiophenyl, and iodo substituents. Such displacements of anti-bromide ions require an amine nitrogen and are a function of the solvent and the choice of metal salt. Reaction rates were faster and product yields were higher in DMSO when compared to DMF and with CsOAc compared to NaOAc. Sodium or lithium salts gave products, except with NaF, where silver fluoride in nitromethane was best for substitution by fluoride. The presence of electron-withdrawing F, OAc, N(3), Br, or SPh substituents in the 6-anti-position slows bromide displacements at the 5-anti-position.
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