On the Winstein rearrangement: Equilibrium and mechanism

Allylic azides are underutilized in organic synthesis when compared to other organic azides or other allylic functionality. This is likely because allylic azides rearrange at room temperature, resulting in a potentially complex mixture of azides. This rearrangement has been termed the Winstein rearrangement. Understanding the mechanism and basic principles governing the allylic azide equilibrium may aid in developing applications for these molecules based on either alkene or azide functionalization. Presented herein is a compilation of the key observations regarding the nature of the allylic azide rearrangement. Mechanistic considerations are explicitly addressed with key examples from the literature.