Recent advancements in visible-light-induced direct C(3)–H functionalization of quinoxalin-2(1H)-ones

Quinoxalin-2(1H)-ones are unique nitrogen-containing organic compounds with wide applications in the agrochemical, pharmaceutical, and chemical industries as well as in material science. During the last decades, visible-light-promoted photoredox catalysis has emerged as a versatile platform for constructing quinoxalin-2(1H)-one scaffolds under exceptionally mild conditions. In this review, we provide an overview of recent advances in photocatalytic direct C(3)–H functionalization of quinoxaline-2(1H)-ones, including the construction of C(3)–C bonds and C(3)–RF/C/O/N/Cl/S/D bonds, as well as the related reaction mechanisms. We aim to enhance the methods for the reaction of quinoxalin-2(1H)-ones at the C–3 position, which have extensive applications in organic synthesis and medicinal chemistry.