Visible-Light-Mediated Azidation of α‑Diazoesters with TMSN₃ via Direct Photoexcitation and S_H2 Mechanism

A visible light-mediated azidation of α-diazoesters with TMSN₃ to synthesize valuable α-azidoesters has been developed. Without using any catalysts and additives, the reaction proceeded smoothly under visible light irradiation at room temperature. A variety of α-diazoesters were successfully converted to the desired α-azidoesters, showing good functional group tolerance. The products could be readily transformed into triazole, α-azidoacid, and α-azidoamide. Mechanistic studies suggested that the reaction is mainly carrying out via direct photoexcitation and S_H2 mechanism. This work provides a novel, mild, and practical protocol for synthesizing α-azidoesters.