Towards the Stable Binding of Mercury: Synthesis and Functionalization of Dibenzyldiazabicyclononane Scaffolds

A new and universally applicable synthesis route for the preparation of functionalized diazabicyclononane compounds was elaborated starting from an easily available 1,5-diphenyl-3,7-diazabicyclo[3.3.1]nonan-9-ol by alkylation of both secondary amines with modified benzyl residues having a bromo, trimethylstannyl, trimethylsilyl, and pinacolboranyl residue in high yields (65-88%). All compounds were used for mercuration reactions to stably bind Hg2+. Finally, the C-9 position of two functionalized diazabicyclononanes was further modified by introducing an azide function allowing a later attachment to biomolecules of interest by using click chemistry.