The Influence of Ion Pairing on the Electroreductive Cleavage of Substituted 9,10-Antraquinones in DMF Solution

Article abstract of DOI:10.1021/jo00386a030

A variety of substituted 9,10-antraquinones with acetates and trifluoroacetates leaving groups at the 2-methyl position were synthesized from 2-methyl-9,10-antraquinones containing 0-2 methoxy substituents.Cyclic voltammograms of the acetates in DMF containing LiClO4 as supporting electrolyte exhibited two reduction waves, the first resulting from the formation of Li(1+) ion pairs of their radical anions and the second from Li(1+) ion pairs of their dianions.Constant potential reduction of the acetates to their dianions followed by air oxidation gave high yields (78-88percent) of their reductive cleavage products, the 2-methyl-9,10-anthraquinones.In contrast, reduction of the acetates to their radical anions led to high yields of their alcohols (the 2-(hydroxymethyl)-9,10-anthraquinones) as a result of saponification.Reduction of the trifluoroacetates in DMF/LiClO4 produced comparable yields of their corresponding reductive cleavage products and alcohols via ion pairs of their radical anions or dianions.