New Synthetic Reactions Catalyzed by Palladium Complexes

Abstract

Palladium-phosphine complexes catalyze four reactions of allylic β-keto carboxylates. Decarboxylation-allylation gives α-allyl ketones. Decarboxylation-dehydrogenation proceeds in boiling acetonitrile to give α, β-unsaturated ketones. An industrial process for methyl jasmonate has been developed based on this reaction. Decarboxylation-deacetoxylation of α-acetoxymethyl-β-keto carboxylates in acetonitrile at room temperature affords α-methylene ketones. Decarboxylation-hydrogenolysis takes place in THF at room temperature by the treatment with ammonium formate to give saturated ketones. Allylic esters and carbamates are converted to corresponding acids and amines by the treatment with formic acid in the presence of palladium catalysts. Thus allyl group can be used as a protecting group of acids and amines. Protection of amino acids by carbamate formation and palladium-catalyzed deprotection proceed without racemization. © 1986 IUPAC