摘要 |
The present invention relates to a novel catalyst system comprising a palladium metal source, a monodentate phosphorus ligand, anionic semilabile ligand, protonic acid, and proton source, and an improved process for the preparation of alpha,beta-unsaturated carboxylic acids and their esters represented ascomprising the steps of reacting alkynes in an aprotic organic solvent, in the presence of said novel catalyst system, in carbon monoxide atmosphere in a homogeneous medium, cooling the reaction mixture to ambient temperature, flushing the reaction vessel with inert gas, removing the solvent by conventional methods, separating the catalyst and isolating the alpha,beta-unsaturated carboxylic acids and their esters by conventional methods.
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