Electro-Inductive Effect: Using an Electrode as a Functional Group to Control the Reactivity of Molecules with Voltage

A new general method of controlling the chemical reactivity of molecules is proposed. Instead of tuning the electronic properties of reactive molecules by employing functional groups that impose different inductive effects to a molecule, we propose to immobilize the parent molecule onto an electrode, for example by installing a thiol group to the molecule and forming a self-assembled monolayer on a gold surface. By applying a voltage the electronic property of the immobilized molecule can be tuned, as is commonly done by decorating the molecule with electron-donating and electron-withdrawing groups. As a proof of principle, it is shown that the base-catalyzed saponification of benzoic ester can be shut down completely by applying a negative voltage, while it can be accelerated by using a positive voltage. Furthermore it is shown that the Suzuki-Miyaura cross-coupling reaction can be affected by the voltage when the arylhalide substrate of the reaction is immobilized on a gold electrode.