Electro-reductive Halogen-Deuterium Exchange and Methylation of Aryl Halides in Acetonitrile

An electro-reductive halogen-deuterium exchange reaction in CD3CN has been developed. Using 9-fluorenone as a mediator, the electro-reduction of several aryl halides proceeded smoothly to give the deuterated products selectively. A methylation reaction of aryl halides also proceeded under similar conditions.