Phenoxysulfonyl azide: a new diazo-transfer reagent for the metal-free conversion of amines to azides

Phenoxysulfonyl azide (PSA, 1) was synthesized from 1,1'-sulfonylbis(2-methyl-1<i>H</i>-imidazole) (2) and studied for its diazo-transfer reactivity. The reaction with 1 was found to convert primary amines 3 into their corresponding azides 4, even without a metal catalyst. Accordingly, PSA is a new diazo-transfer reagent for the metal-free conversion of amines to azides, thereby facilitating the preparation of organic azides from biomolecules.