Water Mediated Green Method Synthesis of Bioactive Heterocycles Reported Between 2012-2021 Accelerated by Microwave Irradiation: A Decennary Update

Abstract

The diverse field of chemistry demands various greener pathways in our quest to maintain sustainability. The utilization of energy inputs (mechanochemistry, ultrasound, or microwave irradiation), photochemistry, and greener reaction media being applied to organic synthesis are the key trends in the greener and sustainable process development in the current synthetic chemistry. These strategic methods aim to address the majority of the green chemistry principles, developing functional chemicals with less amount of waste production. In the synthesis of biologically potential heterocyclic molecules, green chemistry is a topic of great interest. It encompasses all branches of chemistry and is found in the notion of conducting chemical reactions while also conserving the environment through pollution-free chemical synthesis. Water as a solvent media is an excellent choice of solvent in organic synthesis development in the present day, as it is highly abundant, nontoxic, and non-combustible. Medicinal chemists have recently focused their attention on environmentally friendly procedures that use greener solvent media. Using water as a solvent, several studies on the process of optimization and selectivity have been reported, and the combination with microwave irradiation has emerged as a green chemistry protocol to produce high atom economy and yields. In this review, we have compiled microwave-assisted organic synthesis in aqueous media, including examples of the most cutting-edge methodologies employed for the heterocyclic scaffolds used in medicinal chemistry. It covers the most valuable advanced synthetics taking place in the area of heterocyclic molecule synthesis, between the decennary period of 2012 to 2021. The reported work discusses both synthetic and pharmacological applications.