Sustainable One‐Pot Synthesis of <i>N</i> ‐Substituted Pyrroles Using a Multifunctional Cobalt‐Based Catalyst

Abstract The development of novel non‐noble metal‐based heterogeneous catalysts for organic compound synthesis has gained significant relevance in the last decades, aiming to maximize efficiency while minimizing environmental impact. A carbon‐supported nitrogen phosphorus‐cobalt catalyst ( Co 2 PN x @NC ) was found to be active for the one‐pot synthesis of N ‐substituted pyrroles via the reductive coupling of nitrobenzene with 2,5‐hexanedione. This work represents the first successful synthesis of this important group of molecules with &gt;99% conversion and &gt;99% chemoselectivity, using ethanol as a green solvent, non‐noble metal‐based catalyst, H 2 as the reductant, and mild reaction conditions simultaneously. The robustness of the catalyst has been investigated using several techniques, including HAADF‐STEM, HRTEM, XEDS, and PXRD, revealing excellent stability after six successive runs. In the presence of this material, the hydrogenation of readily accessible nitroarenes followed by condensation yields more than 25 pyrroles in good to high yields. Beyond its advantageous step economy, the broad synthetic applicability of this methodology was demonstrated across a range of functionalized substrates, including the preparation of antifungal and antimycobacterial agents on a half‐gram scale. A sustainability assessment of the process using Green Metrics, EcoScale, and GreenStar tools confirmed the effectiveness of ethanol as a green solvent for this process.