Facile azide formation via diazotransfer reaction in a copper tube flow reactor

A copper tube flow reactor is used in the conversion of primary amines into organic azides using imidazole-1-sulfonyl azide hydrogen sulfate. The catalyst is generated in situ from the metallic copper. The reaction can be quenched in acidic environment or via a cycloaddition of the azides formed with an alkyne. The possibility to perform this azide-alkyne cycloaddition using the copper released from the reactor is demonstrated with the synthesis of both a 1,2,3-triazole derivative of benzylamine and of a more complex BODIPY–DOTA adduct.

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