2,2'-Ethylenebis(1,3-dithiane) as a polydentate μ-, μ- and μ-assembling ligand for the construction of sulphur-rich Cu(I), Hg(II) and heterometallic Cu(I)/Hg(II) coordination polymers featuring uncommon network architectures.

With the aim to elaborate novel and inexpensive sulphur-rich materials featuring unusual network architectures, the coordination chemistry of the tetradentate thiaheterocycle 1,2-di(1,3-dithian-2-yl)ethane L1 ligand toward CuX and HgX salts was investigated. When L1 is reacted with CuI in a 1 : 1 ratio, a two-dimensional CP [{Cu(μ-I)Cu}(μ-L1)] (CP1) is formed, in which two out of four S atoms of L1 remain non-coordinated. Upon treatment of L1 with CuI in a 1 : 2 ratio, [{Cu(μ-I)Cu}(μ-L1)] (CP2) is obtained, in which each S atom of L1 coordinates to one copper centre forming a 2D layer.

The structure-defining incorporation of chloride in methyllithium dimers.

We herein present two polymeric solid state structures of pmdta-stabilized methyllithium with co-existing dimeric and tetrameric units, exhibiting partial incorporation of nearly omnipresent LiCl selectively in the dimeric entities. An unexpected interconnecting contact from these positions to a neighboring tetrameric unit is observed.

Insight into the Bonding and Aggregation of Alkyllithiums by Experimental Charge Density Studies and Energy Decomposition Analyses.

In this Article, the organolithiums [((-)-sparteine)LiBu] (), [(ABCO)LiBu] (), and [(ABCO)(LiPr)] () are investigated by means of experimental and theoretical charge density determination to elucidate the nature of the Li-C and Li-N bonds. Furthermore, the valence shell charge concentrations (VSCCs) in the nonbonding region of the deprotonated C-atom will provide some insight on the localization of the carbanionic lone pair. Analysis of the electron density (ρ()), Laplacian (∇ρ()), and the energy decomposition (EDA) confirmed that the Li-C/N bond exhibits astonishingly similar characteristics, to reveal an increasingly polar contact with decreasing aggregate size.

Crystal structure of 2-[bis(benzylsulfanyl)methyl]-6-methoxyphenol.

The title compound, CHOS, , represents an example of an -vanillin-based functionalized di-thio-ether, which could be useful as a potential chelating ligand or bridging ligand for coordination chemistry. This di-thio-acetal crystallizes in the ortho-rhom-bic space group . The phenyl rings of the benzyl groups and that of the vanillin unit form dihedral angles of 35.

Heteroleptic Coordination Environments in Metal-Mediated DNA G-Quadruplexes.

The presence of metal centers with often highly conserved coordination environments is crucial for roughly half of all proteins, having structural, regulatory, or enzymatic function. To understand and mimic the function of metallo-enzymes, bioinorganic chemists pursue the challenge of synthesizing model compounds with well-defined, often heteroleptic metal sites. Recently, we reported the design of tailored homoleptic coordination environments for various transition metal cations based on unimolecular DNA G-quadruplex structures, templating the regioselective positioning of imidazole ligandosides .

Crystal structure of the coordination polymer -poly[[[(acetonitrile-κ)copper(I)]-μ-1,3-dithiolane-κ ::'] hexafluoridophosphate].

The polymeric title compound, [Cu(CHN)(CHS)](PF), represents an example of a one-dimensional coordination polymer resulting from the reaction of [Cu(MeCN)][PF] with 1,3-di-thiol-ane. The cationic one-dimensional ribbon consists of two copper(I) centers each ligated by one aceto-nitrile mol-ecule and inter-connected through two bridging 1,3-di-thiol-ane ligands. One S-donor site of each ligand is κ-bound to Cu, whereas the second S atom acts as a four-electron donor, bridging two Cu atoms in a κ-bonding mode.

Inhibition of Glucose Transporters and Glutaminase Synergistically Impairs Tumor Cell Growth.

Cancer cells sustain growth by altering their metabolism to accelerated aerobic glycolysis accompanied by increased glucose demand and employ glutamine as additional nutrient source. This metabolic adaptation induces upregulation of glucose transporters GLUT-1 and -3, and simultaneous targeting of both transporters and of glutamine metabolism may offer a promising approach to inhibit cancer cell growth. We describe the discovery of the very potent glucose uptake inhibitor Glutor, which targets glucose transporters GLUT-1, -2, and -3, attenuates glycolytic flux and potently and selectively suppresses growth of a variety of cancer cell lines.

The smaller, the better? How the aggregate size affects the reactivity of (trimethylsilyl)methyllithium.

Weighting both the basicity and nucleophilicity of an organolithium compound is crucial for an effective use of these reagents in syntheses. To achieve this, an aggregate of optimal size and reactivity has to be formed by adding suitable donating agents. Against usual expectations, this is not inevitably the smallest possible aggregate.

Unravelling the Synthesis and Chemistry of Stable, Acyclic, and Double-Deficient 1,3-Butadienes: An endo-Selective Diels-Alder Route to Hedgehog Pathway Inhibitors.

The first synthetic access to stable and acyclic 1,3-butadienes with two electron-withdrawing carbonyl groups and their potential to deliver new molecular scaffolds through intriguing endo-selective Diels-Alder cycloadditions are presented. The bicyclic scaffolds produced through the cycloaddition chemistry of electron-deficient dienes afforded potent Hedgehog signaling pathway inhibitors.

Cardenolides and dihydro-β-agarofuran sesquiterpenes from the seeds of Salacia staudtiana.

Phytochemical studies of the seeds of the Cameroonian medicinal plant, Salacia staudtiana, resulted in the isolation and identification of five new cardenolides (1-5) as well as a new dihydro-β-agarofuran (9), along with eight known compounds. The structures of all compounds were elucidated by 1D/2D NMR, ESI-HRMS data and comparison with literature data. The relative configurations of the new compounds were defined by X-ray crystallography analysis, NOESY correlations and coupling constants.

Control of Structures and Emission Properties of (CuI) 2-Methyldithiane Coordination Polymers.

A structurally unique and strongly luminescent nonporous 3D coordination polymer (CP) [CuI(methyldithiane)] , CP3, has been prepared in a quasi-anticipated manner from 2-methyl-1,3-dithiane, L1, and CuI. This CP incorporates an unprecedented CuI cluster built upon two side-fused open cubanes. The crystal structure of CP3 has been determined at 100, 150, 200, 250, 300, 350, and 400 K to study the temperature dependence of the Cu···Cu distances.

Cardenolides from the stem bark of Salacia staudtiana.

Seven new cardenolides, staudtianoside A-F (1-6) and staudtianogenin A (8), were isolated along with six known compounds from the stem bark of the Cameroonian medicinal plant Salacia staudtiana Loes. ex Fritsch. The structures were elucidated by means of ESI-HRMS and NMR spectroscopic methods and by comparison with literature data.

The Reactivity of Benzyl Lithium Species is Regulated by Intermediate Structures.

The reaction of benzyl lithiums is an important aspect in organic and organometallic synthesis. Reported herein are detailed insights into the reactivity of benzyl lithiums as regulated by intermediate structures. By discussing the carbometalation of allylamines and the reaction of the formed benzyl-lithium compounds with electrophiles, the influence of the metal as well as the solvent on the electronic structure of the intermediate is described.

Crystal structure of 1-[(2,4,6-triiso-propyl-phen-yl)sulfon-yl]aziridine.

The title compound, C17H27NO2S, exhibits a distorted geometry of the aromatic ring with elongated bonds at the ipso-C atom. The S atom deviates from the aromatic ring plane by 0.393 (4) Å.

Crystal structure of di-benzyl-dimethyl-silane.

In the title compound, C16H20Si, a geometry different from an ideal tetra-hedron can be observed at the Si atom. The bonds from Si to the benzylic C atoms [Si-C = 1.884 (1) and 1.

Crystal structure of 4-(tri-methyl-germ-yl)benzoic acid.

The title compound, [Ge(CH3)3(C7H5O2)], was obtained as a by-product in the synthesis of the corresponding aldehyde. Two slightly different mol-ecules are present in the asymmetric unit. In both mol-ecules, the geometry of the aromatic ring plane is distorted by varying intensities.