Synthesis of Triarylmethanes by Decarbonylation of 3,3-Diaryl Benzofuranones

A simple
protocol for the synthesis of triarylmethane derivatives
with three different (hetero)­aryl groups by decarbonylation of 3,3-diaryl
benzofuranones, which can easily be prepared via arylation of benzofuranones,
was developed. The reaction proceeds on heating in dimethylformamide
(DMF) in the presence of CH3ONa and water to generate the
products in good to excellent yields. This reaction can be easily
scaled up to give a triarylmethane in a gram scale. Further chemical
manipulation of the products enabled useful transformations of the
phenol ring, including reduction, arylation, cyclization, etc.