A Concomitant Allylic Azide Rearrangement/Intramolecular Azide–Alkyne Cycloaddition Sequence

An intramolecular Huisgen cycloaddition
of an interconverting set
of isomeric allylic azides with alkynes affords substituted triazoles
in high yield. The stereoisomeric vinyl-substituted triazoloxazines
formed depend on the rate of cycloaddition of the different allylic
azide precursors when the reaction is carried out under thermal conditions.
In contrast, dimerized macrocyclic products were obtained when the
reaction was done using copper­(I)-catalyzed conditions, demonstrating
the ability to control the reaction products through changing conditions.