Six-coordinate dinuclear hexaazamacrocyclic complexes of nickel(II), copper(II) and zinc(II) with tetraamide group ligands

Summary A series of 20–24 membered macrocyclic dinuclear transition metal complexes [M₂L¹X₄]-[M₂L⁴X₄] (M = Ni^II, Cu^II or Zn^II; X = Cl or NO₃) have been synthesized by template condensation of diethylenetriamine with dicarboxylic acids. The bonding and stereochemistry of the complexes have been characterized by i.r.,¹H-n.m.r., e.p.r. and electronic spectral studies, magnetic susceptibility and conductivity measurements. The Ni and Zn complexes exhibit octahedral geometry around the metal ion, whereas the Cu complexes possess a distorted octahedral geometry. Each metal ion is coordinated by two amide nitrogens and two secondary nitrogens of the diethylenetriamine moiety; the fifth and sixth coordination sites are occupied by the anions.     

TEAD–YAP Interaction Inhibitors and MDM2 Binders from DNA-Encoded Indole-Focused Ugi Peptidomimetics

DNA-encoded combinatorial synthesis provides efficient and dense coverage of chemical space around privileged molecular structures. The indole side chain of tryptophan plays a prominent role in key, or “hot spot”, regions of protein–protein interactions. A DNA-encoded combinatorial peptoid library was designed based on the Ugi four-component reaction by employing tryptophan-mimetic indole side chains to probe the surface of target proteins. Several peptoids were synthesized on a chemically stable hexathymidine adapter oligonucleotide “hexT”, encoded by DNA sequences, and substituted by azide-alkyne cycloaddition to yield a library of 8112 molecules. Selection experiments for the tumor-relevant proteins MDM2 and TEAD4 yielded MDM2 binders and a novel class of TEAD-YAP interaction inhibitors that perturbed the expression of a gene under the control of these Hippo pathway effectors.     

New nickel(II), copper(II), platinum(II) and palladium(II) complexes of a multidentate sulfur–nitrogen chelating agent

A new, potentially polydentate sulfur–nitrogen chelating agent, 2,6–bis(N-methyl-S-methyldithiocarbazato)pyridine (L) has been synthesized and characterized. With nickel(II) salts, the ligand yields complexes of empirical formula NiLX2·nH2O (X=Cl−, NCS− or NO3−; n=0 or 1) in which it behaves as a quadridentate NSSN chelating agent, coordinating to the nickel(II) ion via the two amino nitrogen atoms and the two sulfur atoms. Magnetic and spectral evidence support a distorted octahedral structure for these complexes. The ligand reacts with copper(II), platinum(II) and palladium(II) salts to yield homo-binuclear complexes of general formula [M2LX4]·nSol (M=CuII, PtII or PdII; X=Cl− or Br−; n=0.5, 1 or 2; Sol=H2O, MeOH or MeCOMe), in which each of the metal ions is in a square-planar environment. These complexes have been characterized by a variety of physicochemical techniques. This revised version was published online in June 2006 with corrections to the Cover Date.