Anhydrous Conditions Enable the Catalyst-Free Carboxylation of Aromatic Alkynes with CO2 under Mild Conditions

The direct carboxylation of aromatic alkynes with CO2, a cheap and widely available C1 source, is the most attractive method for the synthesis of carboxylic acids. Here we show that direct carboxylation of terminal alkynes can be simply performed in near-quantitative yield in four hours with anhydrous Cs2CO3 under mild conditions without need of a metal catalyst.