Direct C–H Carboxylation Forming Polyfunctionalized Aromatic Carboxylic Acids by Combined Br?nsted Bases
CO2 fixation into electron-deficient aromatic C–H bonds proceeds with the combined Br?nsted bases LiO-t-Bu and LiO-t-Am/CsF/18-crown-6 (t-Am = CEtMe2) under a CO2 atmosphere to afford a variety of polyfunctionalized aromat