Selective electrochemical carboxylation of terminal alkyne to 2-alkynoic acid

摘要

The invention relates to a method for carboxylating terminal alkynes in which terminal alkynes are used which have at least one additional aliphatic carbon atom in alpha -position and which do not posses a proton which has a higher acidity than that of the proton of the terminal triple bond. A solution is produced from the terminal alkyne and an aprotic solvent. In an undivided electrolysis cell equipped with a cathode and an anode, the solution is acted upon by carbon dioxide with a pressure which is greater than atmospheric pressure. The cathode and the anode are connected to an electric power source. The aim of the invention is to provide a method in which carbon dioxide is selectively inserted between the terminal C-H-bond, whereby the triple bond remains intact. At the same time, a nickel complex catalyst should be dispensed with. The objective is achieved by carrying out the carboxylation without a catalyst or a catalyst precursor.