iron-catalyzed olefin oxyamidation by utilizing tethered dioxazolones as the nitrenoid precursor to produce valuable β-lactam scaffolds. Mechanistic studies revealed that a relatively strong π-accepting ability of the phthalocyanine ligand is critical in generating the key triplet iron-imidyl radical intermediate to enable the 4-exo-trig-lactamization with the incorporation of oxygen nucleophiles in
The organoselenium-induced ring-closure reactions of γ-substituted β, γ-unsaturated hydroxamic acids afforded cyclic phenylseleno N-hydroxy imidates or phenylseleno N-hydroxy γ-lactams as the kinetically or thermodynamically controlled products, respectively.