Three-component Synthesis of Functionalized N-Protected Tetrasubstituted Pyrroles by an Addition-Elimination-Aromatization Process

A three-component, one-pot, synthesis of N-protected tetrasubstituted pyrroles has been developed by treating nitroallylic acetates with an amine and a beta-keto ester mediated by ceric ammonium nitrate in MeOH. By this method, a diverse array of N-protected pyrrole 2,4-dicarboxylic acid derivatives have been synthesized in 37-76% yield. The reactions proceed smoothly through an interesting S(N)2' displacement and aromatization process.