Synthesis of β-Difluoroalkyl Azides via Elusive 1,2-Azide Migration

An unprecedented 1,2-azide migration has been developed through gem-difluorination of the easily available α-vinyl azides with in situ-generated PhIF2⋅HF. This approach provides a platform for the downstream synthesis of β-difluorinated alkyl azides in high yields with broad substrate scope and excellent functional group tolerance. The DFT calculations suggest 1,2-azide migration occur via a three-membered azacyclic transition state.