Electroreductive room-temperature C-H activations with RuCl₃·nH₂O precatalyst via cathodic ruthenium(iii/ii) manifold

We, herein, disclose a strategy to directly utilize user-friendly RuCl₃·nH₂O for ortho- as well as meta-C-H functionalizations at low temperatures. The key to success was the in situ formation of the active ruthenium catalyst through cathodic electron transfer, setting the stage for C-H activations under exceedingly mild reaction conditions. The robustness of our electrocatalysis process was highlighted by the late-stage diversification of compounds of relevance to chemical, agrochemical, and pharmaceutical industries, as well as simple amines as terminal reductants for the electroreduction. Detailed mechanistic studies by, among others, spectroelectrochemical analysis provided strong evidence for a cathodic reduction manifold.