The Anodic Oxidation of 1,1-Diphenyl Ketones in the Presence of Nucleophiles

<p>The anodic oxidation of 1,1-diphenylethylene has been previously shown to proceed via the intermediate 2,2-diphenylacetaldehyde. Subsequent anodic oxidation of this compound in a 99:1 acetonitrile:water solvent resulted in the isolation of benzophenone. Performing the electrolysis in the presence of alcoholic nucleophiles instead generated α-alkoxyaldehydes which were then oxidized further to form benzhydryl alkyl ethers. In this thesis, 1,1-diphenylacetone and several derivatives thereof were electrolytically oxidized in the presence of various nucleophiles in order to determine the course and mechanism of this reaction and the effect substitutions have on it.</p> <p>It is shown that in the majority of cases, the reaction proceeds to the benzhydryl alkyl ether corresponding to the nucleophile used. The primary mechanism by which this reaction occurs is shown via electrolyses and computational modeling to proceed via a cation radical delocalized across the carbonyl oxygen and one phenyl ring of the benzhydryl moiety in a novel type of conjugation specific to α-benzhydryl ketones. This mechanism stands in contrast to that of anodic oxidation of 2,2-diphenylacetaldehyde, which was shown previously to be oxidized primarily via its enol.</p>