Emerging trends in two- and three-component efficient synthetic strategies for functionalised and fused quinoxalines

Abstract

Quinoxalines are important moieties that mimic the naphthalene core unit, where two carbon atoms (C-1 and C-4) are replaced by N atoms. Many natural products and synthetic compounds contain functionalised and fused quinoxaline precursors having significant physicochemical properties and biological activities. Eventually these quinoxaline derivatives become significant building blocks in modern chemistry research. All these properties of quinoxaline encourage chemists to take up the challenges of discovering new methods for synthesizing functionalised and fused quinoxalines. Several methods were reported for synthesizing quinoxalines, like Ugi reactions, metal-catalysed multi-component reactions, microwave-assisted techniques, and neat reactions, including diversity-oriented synthesis. From the standpoint of green and sustainable perspectives, researchers are striving to achieve the most efficient organic synthesis through greener methods with the utilization of eco-compatible catalysts, reagents, and solvents to improve atom economy, increase product yield, and reduce environmental pollution. In this review, we are going to emphasize the recent advancements in two- and three-component efficient synthetic strategies of functionalised as well as fused quinoxaline derivatives. This review also outlines the schematic rationalization and the limitations of the synthetic methodologies that will enlighten future prospects.