Efficient and rapid synthesis of regioselective functionalized potassium 1,2,3-triazoletrifluoroborates via 1,3-dipolar cycloaddition

In this study, we present a previously unreported method of preparing regiospecific organo-[1,2,3]-triazol-1-aryl-trifluoroborates from haloaryltrifluoroborates via a one-pot 1,3-dipolar cycloaddition reaction. We found that the use of either electron-rich or electron-deficient haloaryltrifluoroborates led to the desired cycloaddition products with good to excellent yields. Furthermore, we successfully carried out the cross-coupling reactions of the obtained triazoles with various aryl halides by means of the Suzuki–Miyaura reaction in the presence of 3 mol % of Pd(PPh3)4 catalyst in a 20% aqueous 1,4-dioxane solution at 100 °C; all these reactions yielded complete conversion to the corresponding products. Besides providing a high level of personnel safety, our highly versatile approach allows the preparation of functionalized organotrifluoborates containing 1,2,3-triazoles with retained functionality.