RuAAC ‘Click Chemistry’-Mediated Synthesis of 1,5-Disubstituted 1,2,3-Triazoles

The modular ruthenium-catalyzed azide-alkyne cycloaddition (RuAAC) is widely explored for direct access of 1,5-disubstituted 1,2,3-triazoles in regioselective manner. Unlike its copper-catalyzed counterpart (CuAAC) variant which predominantly yields 1,4-disubstituted triazoles, the RuAAC offers unique regioselective advantages that extensively expand the synthetic utility of 1,2,3-triazoles. The resulting 1,5-triazole conjugates have been more frequently displayed promise in several areas of pharmaceutical and biochemistry, including inhibitors, building of new materials and electronic devices as well ligands in coordination chemistry and catalysis. This chapter highlights the broad applicability of RuAAC through its implementation in the synthesis of regioselective 1,5-disubstituted 1,2,3-triazole and their conjugates as part of macrocyclic architectures and peptidomimetics along with mechanistic insights and notable applications of resulting conjugates in various emerging fields.