Our environment is in a continuous state of change, which, in turn, demands sustainable, eco-friendly, and safer chemistry techniques. This, in turn, has led to the green chemistry principles coming into the picture in recent years. Over the years, microwave heating has evolved as a green protocol in organic synthesis. The advantages of the safe and environment-friendly MW heating approach include a simple experimental setup, products of high purity with high yields, solvent-free reactions, short reaction times, elimination of the side products, and a decrease in the rate of by-product formation. Heterocycles, especially nitrogen heterocycles, are important not only because they are present in natural products, but because they have widespread applications in pharmaceutical industries as well. These N-heterocycles are part of many biologically active molecules. In the present review, the focus has been laid on the developments in MW-mediated synthesis of biologically important N-heterocycles in the last 2 years (2020-21).
Keywords: Eco-friendly heterocycles, green chemistry, microwave heating, organic synthesis, solvent-free reactions.