Copper-Mediated ortho-Nitration of (Hetero)Arenecarboxylates

Various (hetero)arenecarboxylic acids were converted to the corresponding Daugulis amides and nitrated selectively in the ortho‐position in the presence of [CuNO3(PPh3)2] and AgNO2 at 50 °C. A microwave‐assisted saponification allows regenerating the carboxylate group within minutes, which may then be removed tracelessly by protodecarboxylation, or substituted by aryl‐ or alkoxy‐groups via decarboxylative cross‐coupling. Mild and selective: In the presence of [CuNO3(PPh3)2], aromatic and heteroaromatic 8‐aminoquinolinyl amides undergo selective ortho‐CH nitration under exceptionally mild conditions. A microwave‐assisted cleavage of the amide directing group allows regeneration of the carboxylate group within minutes. The carboxylate may be tracelessly removed in situ, or substituted by aryl or alkoxy groups in decarboxylative processes (see scheme; NH2Q=8‐aminoquinoline, X=CO2H, H, Ar, OR).