Olefins and Functional Derivatives in the Presence of Water

The carbonylation of olefins with CO/HgO had been investigated by many authors in the USA before Reppe started his work. 

However, the reaction proceeded only under drastic conditions (pressure 700 upward to 900 atm) in the presence of mineral acids, BFg or metal halogenides. At that time metal carbonyls had been regarded as catalyst poisons. However, Reppe could prove that olefins react with carbon monoxide and water in the presence of metal carbonyls. The reaction products are saturated carboxylic acids. Whereas Ni(CO)4 is the preferred catalyst in the carbonylation of acetylenes, cobalt, rhodium and ruthenium catalysts are equivalent or superior in olefin carbonylation. Also palladium and hydrochloric acid containing catalyst systems are of special activity in hydrocarboxylation [469-471]. Iron has an accelerating effect [472]. Addition of boric acid to Ni or Co catalysts increases the catalyst life and suppresses the formation of insoluble polymer products [473]. 

Generally in the olefin carbonylation stronger reaction conditions have to be applied than in the carbonylation of acetylenes. In the stoichiometric procedure with Ni(CO)4 as catalyst, 150 °C and CO-pressures of about 50 atm are required and in the catalytic procedure conversion can be reali-2ed at 250 °C and a pressure of 200 atm. Palladium-containing catalysts are active already at 80-150 °C [469-471, 1021]. 

At low temperatures carbonylation of olefins succeeds without pressure with stoichiometric quantities of cobalt hydrocarbonyl, especially in the preparation of esters. 

Metal Carbonyl Catalyzed Carbonylation Reppe Reactions 

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