Research progress in synthesis of nitrogen-rich zole-ring compounds by cycloaddition reaction

Nitrogen-rich zole-ring compounds, as significant N-heterocyclic compounds, have a wide range of applications in medicinal chemistry, bio-conjugation, materials chemistry, etc. The syntheses of nitrogenrich zole-ring compounds by cycloaddition reaction have been paid more and more attention. This review is focused on research progress in synthesis of nitrogen-rich zole-ring compounds by cycloaddition reaction in recent years from various aspects such as the type of catalysts, synthesis of differently substituted products, etc.