Sustainable Pathways to Pyrroles through Iron‐Catalyzed N ‐Heterocyclization from Unsaturated Diols and Primary Amines

Pyrroles are prominent scaffolds in pharmaceutically active compounds and play an important role in medicinal chemistry. Therefore, the development of new, atom‐economic, and sustainable catalytic strategies to obtain these moieties is highly desired. Direct catalytic pathways that utilize readily available alcohol substrates have been recently established; however, these approaches rely on the use of noble metals such as ruthenium or iridium. Here, we report on the direct synthesis of pyrroles using a catalyst based on the earth‐abundant and inexpensive iron. The method uses 2‐butyne‐1,4‐diol or 2‐butene‐1,4‐diol that can be directly coupled with anilines, benzyl amines, and aliphatic amines to obtain a variety of N‐substituted pyrroles in moderate‐to‐excellent isolated yields.