title: Homeopathic ligand-free palladium as a catalyst in the heck reaction. A comparison with a palladacycle.
abstract: [reaction: see text] Ligand-free Pd(OAc)(2) can be used as a catalyst in the Heck reaction of aryl bromides as long as the amount of catalyst is kept between 0.01 and 0.1 mol %. At higher concentrations palladium black forms and the reaction stops. The actual catalyst is monomeric. Palladacycles merely serve as a source of ligand-free palladium in Heck reactions of aryl bromides.
authors.affiliation: DSM Pharma Chemicals-Advanced Synthesis, Catalysis & Development, P.O. Box 18, 6160 MD Geleen, The Netherlands.
authors.forename: André H M
authors.initials: AH
authors.lastname: de Vries
authors.forename: Jan M C A
authors.initials: JM
authors.lastname: Mulders
authors.forename: John H M
authors.initials: JH
authors.lastname: Mommers
authors.forename: Huub J W
authors.initials: HJ
authors.lastname: Henderickx
authors.forename: Johannes G
authors.initials: JG
authors.lastname: de Vries