Rapid and Sustainable Electrochemical Pd Catalyst Generation from Bulk Metal

Palladium catalysts constitute a cornerstone of modern chemistry with upmost scientific and industrial impact. Bulk palladium metal itself is chemically inert, and a sequence of chemical transformations has to be utilized to convert the metal into a Pd precatalyst covered by ligands. However, the "cocktail" concept of catalysis discovered recently has shown that Pd systems can efficiently operate in catalysis without the need for a complicated and expensive preinstalled ligand environment. Here, we point out on a green and sustainable process for the generation of Pd active species without the need for waste-abundant precatalyst-related chemistry. In this work, an electric current was used to generate an active Pd catalyst from a bulk metal in an ionic liquid medium for the efficient cross-coupling of aryl iodides/bromides and boronic acids. A synthetically important Suzuki cross-coupling was utilized as a representative test reaction to confirm the idea. Notably, an electric current is used only at the Pd dissolution stage. Afterwards, the electrodes are removed from the reaction mixture, and a standard reaction procedure can be followed. The reported catalyst preparation process via electrochemical dissolution is potentially compatible with several already existing catalytic methods.