A Regioselective Synthesis of Benzopinacolones through Aerobic Dehydrogenative α‐Arylation of the Tertiary sp3 C-H Bond of 1,1‐Diphenylketones with Aromatic and Heteroaromatic Compounds

Abstract

A regioselective synthesis of symmetrical and unsymmetrical benzopinacolones through aerobic dehydrogenative α‐arylation at the tertiary sp3 CH bond of substituted 1,1‐diphenylketones with aromatic and heteroaromatic compounds, in the presence of K2S2O8 in CF3COOH at room temperature, is described. The reaction is proposed to go via a carbocation intermediate, which could be generated directly from cleavage of the sp3 CH bond of 1,1‐diphenylketone. Subsequent α‐arylation was achieved at the methene sp3 carbon atom of the substituted ketone. A variety of substituted aromatic and heteroaromatic compounds were compatible with this reaction. In addition, benzopinacolones were converted into sterically hindered, tetrasubstituted alkenes and polycyclic aromatic compounds.