Sustainable One-Pot Metal-Free Synthesis of Thiophenes via Room-Temperature Coupling of Pyridinium Bromide Salts and Thioamides

We report a sustainable and operationally simple one-pot protocol for the synthesis of structurally diverse thiophenes through the coupling of pyridinium bromide salts with β-ketothioamides under ambient conditions. The transformation proceeds smoothly at room temperature without the use of metal catalysts, external additives, or harsh reaction conditions, highlighting its environmentally benign nature. The methodology exhibits broad functional group tolerance and delivers thiophene derivatives in good to excellent yields. Notably, the protocol offers advantages such as high atom economy, mild reaction conditions, ease of handling, and scalability, aligning well with key principles of green chemistry. This efficient and eco-friendly approach provides a practical platform for the sustainable construction of thiophene scaffolds of potential relevance in pharmaceutical and materials chemistry.