A Sustainable Approach to Synthesize Tetra‐ and Penta‐Substituted Pyrroles Under Three‐Component One‐Pot Synthesis Using Novel Thiourea‐Derived Organocatalysts

An efficient, synthetically challenging tetra‐ and penta‐substituted pyrroles are reported under one‐ pot three‐component reactions using thiourea‐based organocatalysts under mild reaction conditions. This method is noteworthy for its inexpensive catalyst, easy reaction conditions, air atmosphere, excellent yields, and scalability. Generally, these molecules are synthesized under the Paal–Knorr reaction. However, our protocol offers low organocatalyst loading, catalyst recycling, high atom economy, and a wide functional group tolerance, with product yields up to 91%. The plausible mechanism indicates that H‐bonding between the organocatalyst and the starting materials facilitates the intramolecular Michael addition to afford the intermediate, which then leads to highly substituted pyrrole derivatives.