铜催化的不对称叠氮和炔烃的环加成反应的研究进展

As one of the most important click reactions, the copper-catalyzed azide-alkyne cycloaddition (CuAAC) has found widespread applications. Nevertheless, the exploitation of enantioselective CuAAC remains largely undeveloped. Although the reaction itself does not generate chiral elements, the enantioselective CuAAC can be realized via the desymmetrization of prochiral dialkynes or diazides, as well as the kinetic resolution of racemic azides or terminal alkynes. Notably, enantioselective CuAAC provides efficient access to structurally diverse enantioenriched compounds featuring an azide, terminal alkyne or 1,4-disubstituted 1,2,3-triazoles, which are valuable structural units in organic synthesis or medicinal chemistry. Since the first highly enantioselective CuAAC reaction via desymmetrization of prochiral diynes was reported in 2013, substantial progress has been made in this research area. To date, enantioselective CuAAC has been successfully applied to the construction of central chirality, axial chirality and planar chirality. The recent exciting achievements are summarized, the challenges in this context are briefly discussed, and the synthetic opportunities for future development are outlined.