Synthesis of indazole-based fluorophores

Abstract

Indazoles are commonly used in medicinal chemistry as indole surrogates, nonetheless, their unique electronic scaffold involving two tautomeric forms make them promising for optical applications. This review summarizes synthetic routes to indazole-based fluorophores and other photoactive compounds, including photosensitizers and photochromic molecules. They include N1-, N2-substituted derivatives as well as fused indazoles and detail their various applications as bioprobes, metal ligands, and photoswitches.