ImpactU Versión 3.11.2 Última actualización: Interfaz de Usuario: 16/10/2025 Base de Datos: 29/08/2025 Hecho en Colombia
Essential Oils and Eutectic Solvents in the Povarov Reaction for the Synthesis of Tetrahydroquinolines: A Lesson of Cycloadditions, Stereochemistry, and Green Chemistry
Cycloadditions in combination with multicomponent reactions are among the most valuable synthetic tools used by organic chemists to construct cyclic and heterocyclic compounds in a straightforward way. Although cycloadditions, such as the Diels–Alder reaction, are mainly covered in basic and advanced organic courses for undergraduate students, few experiments are reported in the literature for undergraduate organic chemistry laboratories. Here we describe a new experiment to illustrate the multicomponent imino-Diels–Alder cycloaddition to obtain a tetrahydroquinoline derivative under green chemistry conditions. Different synthesis procedures, including solvent-free reactions, microwave assisted reactions, use of a deep eutectic solvent, and star anise oil as starting material, were evaluated by students. The structure of the synthesized compound was confirmed by NMR spectroscopy (1H, APT, COSY, HSQC), IR spectroscopy, mass spectrometry, and melting point analysis. In addition, the stereochemistry was also proposed by students based on the NMR data.