Krister Zetterberg

Palladium-promoted addition of amines to isolated double bonds☆

Abstract Palladium(II) complexes have been found to promote amination of terminal olefins, to give, after reduction, high yields of amines. Internal olefins may also be aminated, but the yields are moderate to low. Cyclohexene and cyclooctene react very sluggishly. In order to avoid formation of bis(amine)palladium complexes, which is a major side reaction, the temperature has to be kept low. Preliminary mechanistic studies show that three moles of amine are required per mole of palladium to ensure good yields.

The mechanism of nucleophilic addition to η3-allylpalladium complexes: the influence of ligands on rates and regiochemistry☆

Abstract The influence of the ligands L in η 3 -(3-methylbutenyl)palladium(L 2 ) complexes on the rates and regiochemistry of nucleophilic addition has been studied. Acceptor ligands such as phosphines and 1,5-cyclooctadiene have been found to increase the rate of addition as well as the preference for reaction at the more substituted allyl terminus. There is a good correlation between the rates and the 13 C NMR shifts of the more substituted η 3 -allyl terminus, indiating that the NMR shifts can be used to predict acceptor properties of the ligands. There is a fair agreement between the rates and the regiochemistry of the palladium catalyzed nucleophilic displacement of allylic acetate from these complexes and those for the stoichiometric reactions involving η 3 -allyl complexes.

Palladium(II)-promoted 1,4-diamination of 1,3-dienes. Stereochemistry of amination of a π-allylpalladium complex

Reaction of 1,3-dienes with bis(benzonitrile)palladium dichloride and dimethylamine gives 4-dimethylamino π-allylic palladium complexes, which on treatment with AgBF4 or triphenylphosphine are attacked by excess dimethylamine on the face of the π-allyl group opposite to that occupied by palladium to give 1,4-diamines.

Protonation of π-alkene–rhodium(I) complexes leads to σ-alkyl–rhodium(III)—an NMR study

The reaction of Rh(beta-diketonato)(alkene)(2) complexes with CF3SO3H in THF gives Rh(beta-diketonato)(alkyl) species when the alkene is ethylene, cis-butene or 5-methylene-cycloheptene whereas 1,5-cyclooctadiene complexes are unreactive. The reaction was followed by means of NMR-spectroscopy at low temperature and the products were characterized in solution by 2D-NMR techniques. Three possible reaction mechanisms are discussed: ligand assisted proton transfer, hydride transfer and direct protonation of the alkene. The Rh(III)ethyl species are stable against degradation by beta-hydride elimination. However, Rh(III)(beta-diketonato)(n-butyl) complexes lose butene rapidly when ethylene is added and Rh(beta-diketonato)(ethyl) complexes are formed. A mechanism preventing the formation of higher oligomers is proposed, where beta-hydride elimination is followed by rapid alkene exchange and hydride re-insertion

A NEW ROUTE TO SYNTHESIZE 2,9-DICARBONITRILE-1,10-PHENANTHROLINE

Abstract A simple, straightforward method to synthesize 2,9-dicarbanitrile-1, 10-phenanthroline from 2,9-dimethyl-1, 10-phenanthroline via 2,9-dicarbamoyl-1, 10-phenanthroline is described.

Nucleophilic Addition to π‐Olefin‐, π‐Allyl‐ and σ‐Alkyl‐palladium Complexes. Examples of "Umpolung" by the Use of Organometallic Reagents.

Review: Auf der Basis des Wacker-Prozesses [Pd-katalysierte Hydratisierung von Ethen zu Acetaldehyd] wird uber die Veranderung der Reaktivitat von Doppelbindungen durch Metallkomplexbindung berichtet.