Efficient preparation of 4-hydroxyquinolin-2(1H)-one derivatives with silver-catalyzed carbon dioxide incorporation and intramolecular rearrangement.

Although 4-hydroxyquinolin-2(1H)-one derivatives have attracted much attention due to their biological benefits, conventional reactions under harsh heat conditions must be employed to provide these key compounds. In the presence of a catalytic amount of silver salt, various o-alkynylanilines were treated with carbon dioxide and a base under mild reaction conditions to afford the corresponding 4-hydroxyquinolin-2(1H)-one derivatives in high yield.