Nickel-catalysed hydrogen exchange of alkylaromatic hydrocarbons and toluic acid derivatives with deuterium oxide

Abstract

The selective hydrogen exchange of alkyl groups of some alkylaromatic hydrocarbons and toluic acid derivatives was achieved by allowing these compounds to react with deuterium oxide over nickel on kieselguhr at 99°. The observed deuterium distributions and the results of catalyst poisoning experiments can be interpreted in terms of initial π-bonding of the substrates to the catalyst followed by dissociative adsorption at a benzylic carbon atom and transfer of adsorption through the alkyl group by an α-β process. Some nitro- and halo-toluenes underwent little or no exchange.