Carbon dioxide incorporation into alkyne compounds mediated by silver catalysts

We have reported that a silver catalyst with a base was an effective system for the incorporation and utilization of carbon dioxide in organic syntheses under mild reaction conditions. The C≡C triple bond activation by the silver catalysts was assumed to be a key step in these reactions, which was supported by DFT calculations with a model substrate. Based on these reports, we recently developed three new CO₂ incorporations under the mild reaction conditions using our silver catalyst system. In this Personal Account, we describe the silver-catalyzed CO₂ incorporation with C-C bond formation to afford the corresponding γ-lactone derivatives and the synthesis of benzoxazin-2-one derivatives and 4-hydroxyquinolin-2(1H)-one derivatives from alkynylanilines with carbon dioxide catalyzed by silver salts. A silver salt and base catalyst system was applied to CO₂ incorporation with C-C bond formation to afford the corresponding γ-lactone derivatives in good to high yields. This catalyst system is an efficient approach to the synthesis of benzoxazin-2-one derivatives and 4-hydroxyquinolin-2(1H)-one derivatives from alkynylanilines with carbon dioxide.