Eco-friendly Methodologies for the Synthesis of Heterocyclic Systems

The increasing awareness towards environmental pollution and climate changes has impelled research in organic synthesis to search for more environmentally responsible and less impactful solvents in place of toxic and often hazardous Volatile Organic Compounds (VOCs).1 Over the last few years, our research group focused on the sustainable synthesis of heterocyclic compounds such as tetrahydrofuran,2 thiophene,3 and triazole derivatives4 using biodegradable, nature-inspired designer solvents like the so-called Deep Eutectic Solvents (DESs)5 and even water.6 N-containing heterocyclic compounds such as 2,5-diarylpyrazines,7 2-aroylimidazoles and 2,4-diaroyl-6-arylpyrimidines8 are important scaffolds in many biologically active and pharmaceutically relevant molecules. In this communication, the regiodivergent, sustainable synthesis of the aforementioned heterocycles from phenacyl azides is discussed using DESs as environmentally responsible media, acting both as solvents and catalysts, under very mild reaction conditions.