Rapid and Sustainable Electrochemical Pd Catalyst Generation from Bulk Metal.

Palladium catalysts form 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 Pd pre-catalyst covered by ligands. However, the "cocktail" of catalysis concept discovered recently has shown that Pd systems can efficiently operate in catalysis without the necessity of a complicated and expensive pre-installed ligand environment. Here, we point out on a green and sustainable process for Pd active species generation without the need of waste-abundant pre-catalyst-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. Synthetically important Suzuki cross-coupling was utilized as a representative test reaction to confirm the idea. It should be emphasized that 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 a number of already existing catalytic methods.