Green Synthesis of Five- and Six-membered N-heterocycles by Ultrasonic Irradiation in Aqueous Media

Five- and six-membered N-heterocyclic compounds play an important role in medicinal chemistry and the development of new drugs. There is a constant demand for the development of novel biologically potent compounds, and there is also an increasing pressure to develop alternative and more sustainable synthetic methodologies following the Green Chemistry principles. Thus, the present review aims to compile the latest progress in the use of ultrasound irradiation in water conditions to mediate the synthesis of five- and six-membered N-heterocyclic compounds in an environmentally benign manner.