Expeditious and novel synthesis of α-hydroxyesters via rhodium-NHC catalyzed arylation of ethyl glyoxalate

The rhodium-NHC catalyzed arylation reaction of ethyl glyoxalate with aryl and alkyl boronic acids provides an efficient method for the synthesis of α-hydroxyesters. A wide range of α-hydroxyesters (up to 12) were prepared in good to excellent yields. KOtBu was the base of choice, along with tert-amyl alcohol as the solvent. As far as we are aware, this is the first report of this catalytic arylation, using rhodium-NHC catalysts with this specific substrate type.