DYNO‐MILL Mechanochemistry Enables Diaziridine‐Mediated Access to Unsymmetrical Azobenzenes and Electrochemical Tetrazole Synthesis

We report a catalyst‐, acid‐, and base‐free strategy for activation of an N–N‐containing diaziridine/diazo‐derived framework enabling the synthesis of unsymmetrical azobenzenes via a mechanochemical three‐component reaction in a horizontal bead mill (DYNO‐MILL). The process proceeds through in situ formation of a diaziridine intermediate from a formal 2 + 1 annulation of diazo esters and dialkyl azodicarboxylates, followed by electrophile‐induced N─N bond reorganization with aryl diazonium tetrafluoroborates. This solvent‐minimized, operationally simple protocol tolerates air and moisture and is scalable. The resulting azobenzenes serve as versatile substrates for oxidant‐free electrochemical conversion to substituted tetrazoles without chromatographic purification. Green metrics analysis for the tetrazole formation reveals a significant improvement in atom economy (77.33%) compared to literature methods (29.98%–34.96%) and an enhanced Eco‐Scale score (73), highlighting the sustainability of this approach.