Diethylzinc-promoted carboxylation of aryl/alkenyl boronic acids with CO 2 .

The carboxylation of aryl and alkenyl boronic acids with CO 2 is rarely studied and only achieved using copper salts as the catalyst in the presence of a strong base. Herein, we report a diethylzinc-promoted carboxylation of aryl or alkenyl boronic acids with carbon dioxide. The reaction does not require a transition-metal catalyst, and has simple and mild conditions and a broad substrate scope.