A Review of the Use of the Nickel Catalyst in Azide‐Alkyne Cycloaddition Reactions

ABSTRACT Trying to find beneficial and effective catalysis for synthesizing biologically active and valuable 1,2,3‐triazoles is continually being studied to make the procedure more efficient, green, and eco‐friendly. The click reaction is famous in green chemistry for its high selectivity and efficiency in generating 1,2,3‐triazoles with important pharmaceutical and biological activities. 1,3‐Dipolar cycloaddition reaction of organic azides and alkynes by copper‐mediated have a great deal of attention paid to and developed to provide 1,2,3‐triazoles. However, utilizing Cu(II) species frequently requires a reducing reagent, making this approach less atom‐economic. Recently, notable progress has been made in designing and developing metal‐catalyzed click reactions to prepare 1,2,3‐triazoles. As appropriate alternatives to copper catalysts, nickel catalysts can be a good choice in click reactions. This review thoroughly studies the excellent potential of nickel catalysts in azide‐alkyne cycloaddition reactions and recommends using them as proper alternatives to traditional copper catalysts. This review can pave the path for further application of nickel catalysts in click reactions.