Metal‐Controlled Enantiodivergent Tandem Rearrangement to Synthesize 2H‐Azirines

Abstract A metal‐controlled enantiodivergent rearrangement of α‐diazo‐β‐keto oxime ethers has been developed. Switching the metal catalyst from Co(II) to Fe(II) with an identical ligand completely reverses the asymmetric induction. Both enantiomers of chiral 2 H ‐azirines and its derivatives are accessible under thermal or photolytic conditions. The cobalt‐based reaction is highly efficient even at 0.05 mol% catalyst loading. Mechanistic studies, including kinetic experiments and density functional theory calculations, reveal that distinct electronic properties of cobalt and iron modulate intermediate conformations, thereby altering the enantioselectivity.