Recent Synthetic Strategies of Quinoxalines and Quinoxalinone Derivatives under Visible-Light Irradiation

Abstract: Heterocyclic compounds, which are commonly found in nature, are important molecules with fascinating biological and pharmacological effects. Specifically, scaffolds derived from quinoxaline and quinoxalinone are a family of N-heterocyclic molecules with a variety of biological properties, including herbicidal, anti-tumor, anti-cancer, and anti-malarial effects. The way chemists tackle difficult bond-forming reactions has been completely transformed by visible-lightmediated reactions, which have become a potent tool in organic synthesis. This mini-review discusses advances in the field from 2021 to the present and reviews previous work on photocatalytic synthesis methods to quinoxaline and quinoxalinone derivatives. This compilation is the first of its kind to focus solely on the use of photoredox systems in the synthesis of N-heterocyclic frameworks, such as quinoxalines and quinoxalinones. The type of photocatalyst/ photocatalyst-free strategy used to generate the target scaffolds determines the structure of this study under visible-light irradiation (white, blue, purple, xenon, and tungsten). Visible-lightmediated photocatalysis is emerging as a sustainable alternative to conventional syntheses in terms of regio/chemoselectivity; it enables radical chemistry and typical single-electron transfer reactions that are difficult to perform with current techniques. It successfully promotes modifications such as C-H functionalization, C-C, carbon-heteroatom, and heteroatom-heteroatom bond formation reactions.