1,3‐Sulfinate Migration Triggered by α‐Imino Carbene and Divergent Zwitterion Cyclization: Synthesis of Cyclopropane, Dihydropyrrole, and Azepane Ring Systems

Abstract

AbstractCyclopropane, dihydropyrrole, and azepane ring systems were synthesized conveniently from sulfinate‐tethered triazoles. The divergent synthetic strategy started with the unique 1,3‐sulfinate migration of an α‐imino carbene. The efficient reaction allowed control of the zwitterion bearing multiple reactive sites depending on the increased stability of the resulting carbocation and anion. The sulfinate was converted to a sulfone after the group migration, and a stable anion bearing two electron‐withdrawing groups was thus formed. Catalytic amounts of iodide acted as a switch for the synthesis of cyclopropanes and dihydropyrroles. The reaction merits including readily available substrates, mild reaction conditions, and excellent functional group compatibility qualified this protocol a possible synthetic tool for cyclic compounds, especially for N‐heterocycles.