Synthesis of functionalized organotrifluoroborates via the 1,3-dipolar cycloaddition of azides

We have successfully prepared potassium azidoalkyltrifluoroborates from the corresponding halogen compounds in 94 - 98% yields through a nucleophilic substitution reaction with NaN3. In the presence of various alkynes and Cu(I) as a catalyst, these azidotrifluoroborates easily formed 1,4-disubstituted organo-[1,2,3]-triazol-1-yl-trifluoroborates in 85-98% yields. This method was then developed into a facile one-pot synthesis for the preparation of various organo-[1,2,3]-triazol-1-yl-trifluoroborates using haloalkyltrifluoroborates as the starting materials.