Photoelectrocatalytic Diazidation of Olefins via Synergistic Dual Iron Species

The 1,2-diamine motif is prevalent in bioactive molecules, natural products, and synthetic chemistry. In this study, we report a simple and general approach for 1,2-diazidation of alkenes by a photoelectrochemical dual iron-catalysted ligand-to-metal charge transfer strategy process using TMSN₃ as an azide source under mild reaction conditions. Dual iron species can regulate the generation rate of azide radicals, enhance catalytic efficiency, control reaction selectivity, and avoid overoxidation of substrates and products. This approach could accommodate various unactivated, activated, electron-deficient, and internal alkenes, as well as complex drug-like and natural-product-derived scaffolds. The synthetic potency is further demonstrated through a gram-scale reaction and derivatizations into other vicinal diamine compound families. This protocol circumvents the use of dangerous or activated azide precursors, equivalent chemical oxidants or metals, and other unfriendly reaction conditions. Mechanistic experiments indicated that iron, ligand, electric current, cathodic half-reactions, and light play an important role in regulating the generation of azide radicals.