A versatile copper-catalyzed [3 + 1 + 1] annulation of oximes and isocyanates with AgNO3 is described. In this conversion, AgNO3 and isocyanates instead of conventional azide or diazonium reagents were used as the nitrogen source. This three-component transformation was achieved by cleaving N–O/C–H/C–N bonds and building C═N/N–N bonds, which provides a strategy to prepare N-2-aryl-1,2,3-triazoles with
Palladium-Catalyzed Olefination and Arylation of 2-Substituted 1,2,3-Triazole <i>N</i>-Oxides
作者:Wei Liu、Yahui Li、Bo Xu、Chunxiang Kuang
DOI:10.1021/ol401002w
日期:2013.5.17
Two highly efficient protocols for the regioselective synthesis of 2-substituted 4-alkenyl- and 4-aryl-1,2,3-triazoles by the palladium-catalyzed C–H functionalization of 1,2,3-triazoleN-oxides are reported. A possible pathway of direct alkenylation with 1-octene and vinyl acetate is discussed.
The reactions of α‐bromoacetophenones with methylhydrazine in refluxing acetic acid generated 2‐methyl‐4‐aryl‐2H‐[1,2,3]triazoles in good yields. The method was developed by the reactions of α‐bromoacetophenones with phenylhydrazines in the presence of cupric ion, leading to 2,4‐diary‐2H‐[1,2,3]triazoles. The structures were established on the basis of corresponding IR, 1H NMR, and elemental analysis data.