Synthesis of multimetallic dendrimers through non-covalent interactions.

Hexa-ammonium functionalized Dendriphos ligands and mono-sulfonate functionalized metal complexes have been used as building blocks for the preparation of multimetallic dendritic assemblies. These metallodendrimers consist of a single metal centre surrounded by an oligocationic shell formed by the coordinated Dendriphos ligands and multiple associated anionic organometallic complexes.

Efficient synthesis of β-chlorovinylketones from acetylene in chloroaluminate ionic liquids.

A method for the Friedel-Crafts-type insertion reaction of acetylene with acid chlorides in chloroaluminate ionic liquids is presented. The use of ionic liquids not only serves to avoid the use of carbon tetrachloride or 1,2-dichloroethane but also suppresses side reactions, notably the polymerization of acetylene, which occurs in these chlorinated solvents. Consequently, the products can be isolated using a simpler purification procedure, giving a range of aromatic and aliphatic β-chlorovinyl ketones in high yield and purity.

Coulombic inter-ligand repulsion effects on the Pt(II) coordination chemistry of oligocationic, ammonium-functionalized triarylphosphines.

The Pt(II) coordination chemistry of oligocationic ammoniomethyl- and neutral aminomethyl-substituted triarylphosphines (L) is described. Complexes of the type PtX(2)(L)(2) (X = Cl, I) have been isolated and characterized. For the hexa-meta-ammoniomethyl-substituted ligands [1](6+) and [2](6+), two ligands always occupy a trans-configuration with respect to each other in complexes of the type PtX(2)(L)(2), while for the tri-para-ammoniomethyl-substituted ligand [7](3+), the trans/cis ratio is dependent on the ionic strength of the solution.

Steric, electronic, and secondary effects on the coordination chemistry of ionic phosphine ligands and the catalytic behavior of their metal complexes.

The effects of introducing ionic functionalities in phosphine ligands on the coordination chemistry of these ligands and the catalytic behavior of the corresponding metal complexes are reviewed. The steric and electronic consequences of such functionalizations are discussed. Apart from these steric and electronic effects, the presence of charged groups often leads to additional, supramolecular interactions that occur in the second coordination sphere of the metal complex, such as intramolecular, interligand hydrogen bonding and Coulombic repulsion.

Hexacationic Dendriphos ligands in the Pd-catalyzed Suzuki-Miyaura cross-coupling reaction: scope and mechanistic studies.

The combination of Pd(2)dba(3) x CHCl(3) and hexacationic triarylphosphine-based Dendriphos ligands (1-3) leads to a highly active catalytic system in the Suzuki-Miyaura cross-coupling reaction. Under relatively mild reaction conditions, nonactivated aryl bromides and activated aryl chlorides can be coupled at a low Pd loading (0.1 mol %).

Organic transformations on sigma-aryl organometallic complexes.

This work reviews recent developments in the field of organic transformations on sigma-aryl organometallic complexes. The general notion that M--C sigma bonds are kinetically labile, highly reactive, and incompatible with typical reaction conditions met in organic synthesis has limited the use of these synthetic strategies thus far. However, organic transformations on metal-bound sigma-aryl fragments are being used more and more by chemists in both industry and academia.

A new, easily recyclable arylating agent based on a diphosphino-digold(I) complex.

The synthesis of two organogold(I) complexes, [(Au(NCN))2(dppbp)] (6) and [(Au(Phebox))2(dppbp)] (9), and their application in subsequent transmetalating reactions are described. A trinuclear organogold(I) complex, [(AuCl)3(tdpppb)] (4) is also reported, which exhibits a surprisingly high solubility in dichloromethane. It was found that 6 and 9 can cleanly transfer the anionic NCN-([C(6)H(3)(CH(2)NMe(2))2-2,6]-) or Phebox-([2,6-bis(oxazolinyl)phenyl]-) moiety to Ti(IV) and Pd(II) centers, respectively.