Carboxylation of C(sp2)–H bonds in quinolone derivatives with CO2: facile synthesis of quinolone carboxylic acids†

Quinolone carboxylic acids and derivatives are widely regarded as privileged scaffolds due to their broad-spectrum biological activities. Herein, we report a direct and efficient carboxylation of C(sp²)–H bonds in quinolone derivatives with CO₂. This work offers a highly atom- and step-economical approach to a variety of quinolone-3-carboxylic acids and derivatives with good yields. Moreover, this methodology provides a convenient route to access both marketed drugs and other bioactive molecules. Notably, the derived glycogen synthase kinase 3β (GSK-3β) inhibitor VP0.7 exhibits promising cytotoxic activity against several cancer cell lines, highlighting its potential application in drug discovery.