Ru-Catalyzed Alkene Isomerization Triggers Winstein Rearrangement for Stereoselective Allylic Azide Synthesis

Abstract A tandem Ru-catalyzed alkene isomerization/Winstein rearrangement sequence enables the stereoselective synthesis of E-allylic azides from alkenyl azides. Ru-catalyzed alkene isomerization generates an allylic azide intermediate that undergoes a spontaneous [3,3]-sigmatropic rearrangement, shifting the Winstein equilibrium toward the thermodynamically favored product. A stereochemical investigation revealed partial erosion of enantiomeric purity, providing insight into the tandem process. The synthetic utility of this method was demonstrated through a scale-up experiment and one-pot downstream transformations.