Palladium-catalyzed enantioselective multiple carbonylation of 1-olefins. Synthesis of optically active 2-oxo-pentanedioates and butanedioates

In the presence of an oxidant such as 1,4-benzoquinone, cationic palladium(II) complexes catalyze a multiple carbonylation of 1-olefins to 2-oxopentanedioates and to butanedioates. The selectivity to 2-oxopentanedioates is reasonable only for styrene as the substrate and increases by increasing the carbon monoxide pressure. The triple carbonylation is regiospecific for styrene, whereas the two possible regioisomers are formed for the aliphatic olefins. The results of regioselectivity and enantioselectivity are interpreted on the basis of common reaction intermediates for the two multiple carbonylation processes.