Tetrazoles are an important class of heterocycles in a wide range of applications, such as, organocatalysis and transitionmetal catalysis, propellants, explosives, and perhaps most commonly, as non-classical isosteres of carboxylic acids in medicinal chemistry.[1, 2] This broad utility has prompted significant effort toward tetrazole synthesis,[3] and notable among these is that of Sharpless, in which aqueous zinc bromide (ZnBr2) facilitates the assembly ...