Synthesis of Polysubstituted Pyrroles via (2 + 2 + 1) Cyclization of Enone Oxime Ethers with Alkynes and Diaziridinone.

Herein, we report an efficient palladium-catalyzed (2 + 2 + 1) cyclization strategy for the synthesis of polysubstituted pyrroles from enone oxime ethers, alkynes, and diaziridinone. This transformation is proposed to proceed through a cascade process involving C-C bond cleavage, migratory insertion of alkyne into the C-Pd bond, C-H activation, and subsequent amination with diaziridinone. Notably, this protocol enables the direct incorporation of bioactive fragments into the pyrrole skeleton, highlighting its synthetic utility in medicinal chemistry applications.