Indolo[2,3-b]quinoxaline (IQ) Derivatives: Synthesis, Pharmacological Properties, and Applications in Organic Electronics and Sensors

Abstract: Quinoxaline and indoline-2,3-dione, as heterocyclic scaffolds, provide significant features as crucial components for material science and the construction of new pharmacological drugs. Several interesting biological and technical characteristics have been established by their combination in indolo[2,3-b]quinoxaline (IQs) moieties. The synthesis, therapeutic chemistry, and technical application of indolo[2,3-b]quinoxalin ring systems (IQs) have been the focus of numerous studies of research in recent years. This review presents the synthesis of these derivatives by the condensation of aryl‑1,2‑diamines with indoline‑2,3‑diones (isatins) in boiling acetic acid or through microwave‑assisted approaches. Additionally, the review highlights the usage of IQs in several electronic applications, including organic transistors, deep-red OLEDs, electron-transporting layers, chemical sensors, and emitting layers. These synthetic approaches and technical usage of IQs enable the efficient building of these scaffolds, accelerating further discovery and examination of their medicinal and technical potential.