Synthesis and Utilization of 1 H -Indazole N -Oxides in the Production of C3-Functionalized 1 H -Indazoles.

The medicinal importance, natural rarity, and challenges associated with the synthesis of C3-functionalized 1 H -indazoles have propelled the development of novel and practical 1 H -indazole N-oxides for the production of diverse arrays of C3-functionalized 1 H -indazoles. The use of 1 H -indazole N-oxides has been remarkably effective for the selective introduction of diverse functional groups, including amino (NHAr), chloro (Cl), hydroxy (OH), sulfonyl (SO2 Ar), aromatic (Ar), olefin, alkyl, and N-formyl (NRCHO) groups, to indazole pharmacophore molecules. This review offers a concise overview of the synthetic approaches and practical applications of 1 H -indazole N-oxides, including recent studies conducted by the authors. Transformative reactions involving 1 H -indazole N-oxides not only offer strategies for synthesizing C3-functionalized 1 H -indazoles but also hold significant potential in medicinal chemistry. 1 Introduction 2 Synthetic Approaches and Applications of 1 H -Indazole N -Oxides 3 Summary and Outlook [ABSTRACT FROM AUTHOR]