Copper(I)-Catalyzed Interrupted CuAIAC/Disulfuration Reaction for the Synthesis of <i>N,N</i> ′-Bicyclic Pyrazolidinone Disulfides

A series of <i>N,N</i>'-bicyclic pyrazolidinone disulfides were prepared via a copper(I)-catalyzed interrupted CuAIAC/disulfuration cascade reaction. This protocol proceeded through a copper(I)-catalyzed azomethine imine-alkyne cycloaddition, followed by the interception of the in situ-formed cuprate-pyrazolidinonate intermediate with trisulfide dioxides. The reaction exhibits complete regioselectivity, mild conditions, and broad functional group compatibility, including halogen, cyano, and heterocycle, making it a highly efficient synthetic strategy.