Use of Ring-Expanded Diamino- and Diamidocarbene Ligands in Copper Catalyzed Azide–Alkyne “Click” Reactions

The two-coordinate ring-expanded N-heterocyclic carbene copper­(I) complexes [Cu­(RE-NHC)2]+ (RE-NHC = 6-Mes, 7-o-Tol, 7-Mes) have been prepared and shown to be effective catalysts under neat conditions for the 1,3-dipolar cycloaddition of alkynes and azides. In contrast, the cationic diamidocarbene analogue [Cu­(6-MesDAC)2]+ and the neutral species [(6-MesDAC)­CuCl]2 and [(6-MesDAC)2(CuCl)3] show good activity when the catalysis is performed on water.

已成功制备双配位扩环氮杂环卡宾(ring-expanded N-heterocyclic carbene, RE-NHC)铜(I)配合物[Cu(RE-NHC)₂]⁺（配体RE-NHC分别为6-Mes、7-o-Tol、7-Mes），该类配合物在无溶剂条件下可高效催化炔烃与叠氮化物的1,3-偶极环加成反应。与之相比，阳离子二酰胺卡宾(diamidocarbene)类似物[Cu(6-MesDAC)₂]⁺以及中性配合物[(6-MesDAC)CuCl]₂和[(6-MesDAC)₂(CuCl)₃]，在水相体系中进行催化反应时同样表现出优异的催化活性。