A comparison of the effectiveness of sulphuric acid and trifluoromethanesulphonic acid in Koch carboxylation reactions

Abstract

Trifluoromethanesulphonic acid has been found to be far superior to 95% sulphuric acid for the carboxylation of olefins, alcohols, and esters with carbon monoxide at atmospheric pressure. This is attributed to the higher acidity of CF₃SO₃H and also the higher solubility of carbon monoxide in this acid. At higher carbon monoxide pressures the difference in behaviour of the two acids is much less marked as, under these conditions, the carbon monoxide concentration is not a limiting factor.