Synthesis of (Z)-fluoroallyl azides through aluminium-mediated defluorinative functionalization reactions

The reaction of difluorohomoallyl alcohols with Me2AlCl in CH2Cl2 selectively gave (Z)-fluoroallyl chlorides via SN2′ type defluorinative chlorination. These chlorides were easily converted to the corresponding (Z)-fluoroallyl azides by the sequential nucleophilic azidation reaction using NaN3. Direct defluorinative azidation of the difluorohomoallyl alcohols was also achieved by treating with Me3SiN3 in the presence of Al(Oi-Pr)3. Fluoroallyl azides thus obtained successfully applied to the Huisgen 1,3-dipolar cycloaddition chemistry.