Aryl Boronic Esters Are Stable on Silica Gel and Reactive under Suzuki−Miyaura Coupling Conditions

A wide range of aryl boronic 1,1,2,2-tetraethylethylene glycol esters [ArB(Epin)s] were readily synthesized. Purifying aryl boronic esters by conventional silica gel chromatography is generally challenging; however, these introduced derivatives are easily purified on silica gel and isolated in excellent yields. We subjected the purified ArB(Epin) to Suzuki−Miyaura couplings, which provided higher yields of the desired biaryl products than those obtained using the corresponding aryl boronic acids or pinacol esters.