Levulinic acid and its esters synthesized by the palladium-catalyzed carbonylation of 3-buten-2-one, 4-alkoxy-2- butanone, 4-chlorobutanone, and the products of reaction of acetone with formaldehyde or a formaldehyde precursor, preferably trioxane, in the presence of water or an alkanol contg. dissolved HCl. The synthesis is regiospecific. The catalytic system is highly active only in the presence of excess HCl at 100-110°. The yield increases with increasing CO pressure concn. of palladium, concn. of the acid (up to a HCl/substrate ratio of 2.5-3), concn. of the substrate and of the alkanol dissolved in a solvent such as benzene. The following reactivity order has been established; primary alc. > secondary > tertiary and BuOH > PrOH > EtOH. Palladium(0) or palladium(II) complexes can be used as catalyst precursors. They decomp. to palladium metal, which is the true catalyst. Pd/C is also active. The possible modification of the microstructure of the catalyst is discussed on the basis of the reactivity of the metal with the reaction medium.

Levulinic acid synthesis via regiospecific carbonylation of methyl vinyl ketone or of its reaction products withhydrochloric acid or an alkanol or of a mixture of acetone with a formaldehyde precursor catalyzed by a highly activepalladium-hydrochloric acid

TONIOLO, Luigi
1990-01-01

Abstract

Levulinic acid and its esters synthesized by the palladium-catalyzed carbonylation of 3-buten-2-one, 4-alkoxy-2- butanone, 4-chlorobutanone, and the products of reaction of acetone with formaldehyde or a formaldehyde precursor, preferably trioxane, in the presence of water or an alkanol contg. dissolved HCl. The synthesis is regiospecific. The catalytic system is highly active only in the presence of excess HCl at 100-110°. The yield increases with increasing CO pressure concn. of palladium, concn. of the acid (up to a HCl/substrate ratio of 2.5-3), concn. of the substrate and of the alkanol dissolved in a solvent such as benzene. The following reactivity order has been established; primary alc. > secondary > tertiary and BuOH > PrOH > EtOH. Palladium(0) or palladium(II) complexes can be used as catalyst precursors. They decomp. to palladium metal, which is the true catalyst. Pd/C is also active. The possible modification of the microstructure of the catalyst is discussed on the basis of the reactivity of the metal with the reaction medium.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10278/35563
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