Synthesis of new derivatives of a representative o-quinone scaffold by reduction at the electrode

The concomitant electrochemical reduction of 9,10-phenanthrenequinone and benzenediazonium tetrafluoroborate, under constant potential conditions (?0.5 V vs Ag/Ag⁺), has been performed in different organic solvents. An interesting entry to new C–C radical coupling products is here described. Another cathodic pathway where the anion radical intermediate acts as an EGB is also described. The electrochemical behaviour of both systems and mechanistic proposals are given.