Issues in the Electrochemical Dehydrogenation of Secondary Amines

Abstract Herein, we report mechanistic studies on the ruthenium-catalyzed dehydrogenation of secondary amines using 2,6-dimethoxybenzoquinone as an electrochemically regenerable mediator. The Shvo catalyst [(C5Ph4O)RuH]2 operates at 90 °C at a potential of +0.4 V to dehydrogenate the amine to the imine at the anode. Hydrogen gas is generated at the cathode. Issues such as protonation of the amine are identified and circumvented by using lutidine as a proton-transfer base.