Transition-metal-catalyzed nitrene transfer is a convenient method to introduce nitrogen
into simple substrates through either alkene aziridination or C–H bond amination.
Silver complexes have an unusual capability to accommodate a broad range of N-donor
ligands and coordination geometries in catalysts competent for nitrene transfer. This
behavior has resulted in the ability to achieve tunable chemoselectivity between aziridination
and C–H bond amidation, as well as tunable site-selective functionalization between
two different C–H bonds. In this paper, efforts to engage the diversity of silver
and rhodium catalysts to accomplish selective and tunable aziridination of mixtures
of alkenes are discussed. It was found that the selectivity of dinuclear Rh catalysts
is dictated largely by steric effects, while the identity of the ligand on silver
can be tuned to influence whether the steric or electronic features in the competing
alkenes is the primary factor controlling which precursor is preferentially aziridinated.
Key words
nitrene transfer - silver - alkene - aziridine - site-selective
