Poly(propyleneimine)-iminopyridyl-palladium dendrimers, bearing palladium moieties on the periphery, were found to be effective catalyst precursors for Heck coupling. The dendritic complexes achieved high conversions in the reaction of iodobenzene with methyl acrylate, styrene and 1-octene. Reactions with electron-deficient olefins yield mainly beta-arylated products, whilst electron-rich olefins, yield a mixture of arylated products (beta, alpha), cis/trans isomers and beta,beta-disubstituted compounds. Generally, the metallodendrimer leads to higher conversions and the reactions proceed at a faster reaction rate, when compared to reactions using an analogous mononuclear palladium complex or the palladium salt, PdCl2 (C) 2004 Elsevier B.V. All rights reserved.