Catalytic C-H Carboxylation of Terminal Alkynes with Carbon Dioxide

Within the past years, several catalyst systems have been discovered that promote the carboxylation of terminal alkynes with formation of propiolic acids. This reaction concept is particularly topical in that it involves the functionalization of a C-H bond and the incorporation of CO2 into an organic molecule without need for strong bases or aggressive organometallic reagents. The present article reviews the development of this new reaction type and critically compares the reaction and catalyst concepts disclosed in the literature.