Functionalization of indazoles and azaindazoles via palladium-catalyzed cross-coupling and transition metal-free C–H activation: current advances and applications – an eight-year update

The functionalization of indazoles and azaindazoles is an important area of research in medicinal chemistry and materials science. This review provides an overview of recent advancements in indazole and azaindazole framework modification, emphasizing halogenation, functionalization using palladium-catalyzed strategies as well as emerging transition metal-free approaches. It explores various methodologies for synthesizing biologically active compounds and functional materials, highlighting the importance of regioselectivity in these processes. This review also offers insights into the current state of the field and identifies promising directions for future research. The aim is to provide more sustainable and efficient synthetic pathways for indazole and azaindazole derivatives.