Ag(I)-Catalyzed C–C Bond Cleavage and Re-Assembly Reactions Between 2<i>H</i>-Azirines and α-Carbonyl Sulfoxonium Ylides

In this report, we describe the Ag(I)-<i>N,N'</i>-dioxide complex-catalyzed C-C bond cleavage and reassembly reactions between 2<i>H</i>-azirines and α-carbonyl sulfoxonium ylides, leading to an unusual formal insertion of enamine into unstrained C-C bonds. This procedure provides rapid access to a series of otherwise inaccessible α,β-unsaturated imines. Detailed mechanistic studies reveal that this catalytic transformation proceeds through a tandem sequence involving a radical-mediated formal [3 + 2] cycloaddition reaction, C-C bond cleavage, and elimination processes.