HF-Free, Direct Synthesis of Tetrabutylammonium Trifluoroborates

The direct preparation of tetrabutylammonium trifluoroborates from boronic acids without using HF or the corresponding potassium salt is described. The method is highly efficient for aromatic and aliphatic boronic acids. This protocol, however, was less efficient for boronic acids that were sensitive to protiodeboronation.