Cu(I)‐Catalyzed Coupling Reactions of β‐Nitrostyrene, 1,3‐Dicarbonyl compound & Aryl amine: An Efficient Method For the Synthesis of Polysubstituted Pyrroles

Abstract

A convenient Cu(I) Catalyzed three‐component coupling strategy for the synthesis of polysubstituted pyrroles is developed using simple and readily available building blocks like, 1, 3‐dicarbonyl compound, aryl amine, and β‐nitrostyrene. CuI has been rarely explored for the pyrrole ring synthesis and a comparative analysis of our current catalyst with a range of previously reported catalysts suggested that, CuI is one of the best catalysts for the multicomponent synthesis of polysubstituted pyrrole derivatives. Notably, this process has several advantages, including a simple and practical set‐up with hassle free reaction conditions, extensive substrate scope, short reaction time, high atom economy and environmentally favorable approach. This methodology provides an alternative approach to the highly substituted pyrroles and under optimized reaction conditions, polysubstituted pyrroles were formed in good to excellent yields. Cu(I) catalyzed Mannich reactions followed by Michael addition reactions along with subsequent intramolecular cyclization are believed to be the key steps of this reaction process.