Copper‐Catalyzed [3 + 2] Cascade Annulation of β ‐Enamino Esters With β ‐Ketodinitriles to Access 1 H ‐Pyrrol
Pratima Singh, Anup Kumar Sharma, Krishna Nand SinghA novel and efficient method for the synthesis of multifunctionalized N–H pyrroles has been developed through a Cu‐catalyzed [3 + 2] cycloaddition of β ‐enamino esters (NH 2 ‐enamine) with β ‐ketodinitriles in DMF at 60 °C for 12 h. The reaction involves a cascade cyclization process followed by oxidation of the α ‐substituted malononitrile unit, enabling access to unprecedented pyrrole‐3‐carbonyl cyanide motifs. The methodology features a broad substrate scope, good functional group tolerance, and mild reaction conditions, providing an expedient route to these valuable heterocyclic scaffolds.