An Electric Field-Induced Change in the Selectivity of a Metal Oxide-Catalyzed Epoxide Rearrangement

The rearrangement of cis-stilbene oxide catalyzed by Al2O3 was studied in the presence of interfacial electric fields. Thin films of Al2O3 deposited on Si electrodes were used as the opposing walls of a reaction vessel. Application of a voltage across the electrodes engendered electrochemical double layer formation at the Al2O3-solution interface. The aldehyde to ketone product ratio of the rearrangement was increased by up to a factor of 63 as the magnitude of the double layer charge density was increased. The results support a field-dipole effect on the selectivity of the catalytic reaction.