XAT-Generated Azirinyl Radicals in Selective Giese-Type Alkylation of 2 <i>H</i> -Azirines

We report a radical strategy for direct C2-alkylation of 2<i>H</i>-azirines via generation of elusive 2<i>H</i>-azirinyl radicals. These highly reactive intermediates are accessed under mild halogen-atom transfer conditions from readily available 2-haloazirines. The resulting cyclic radicals undergo regioselective Giese-type additions to electron-deficient alkenes, retaining the azirine ring. Mechanistic studies, including spin-trapping and DFT analysis, support a free radical pathway. The adducts undergo base-promoted ring expansion to yield 6-aminopyridines, underscoring this platform's synthetic utility.