The present invention relates to a catalytic process for preparing an α,β-ethylenically unsaturated carboxylic acid salt, comprising contacting an alkene and carbon dioxide with a carboxylation catalyst being a transition metal complex, an alkoxide, and an organic solvent, to obtain an α,β-ethylenically unsaturated carboxylic acid salt, the organic solvent being incompletely miscible with water at a pressure of 1 bar at at least one temperature T and selected from amides and ureas, T being a temperature in the range from 10° C. to 90° C.