An unexpected stereochemical course of dihydroimidazolium ylide cycloadditions

An unexpected stereochemical course of dihydroimidazolium ylide cycloaddition

Two Cu(II) complexes from an N-alkylated benzimidazole: synthesis, structural characterization, and biological properties

<div><p>Two mononuclear copper(II) complexes, [Cu(L)Cl₂](CH₃OH)₂ and [Cu(L)(NO₃)₂], were prepared and characterized by spectroscopic and analytic methods, where L is 2,6-bis(1-butyl-1<i>H</i>-benzo[<i>d</i>]imidazol-2-yl)pyridine. Molecular structures of the complexes were determined by X-ray diffraction. The X-ray data revealed that the complexes are mononuclear and coordination geometry around Cu(II) is distorted square pyramidal. The complexes were screened for their <i>in vitro</i> antibacterial and antifungal activities. The complexes show moderate antifungal activities against <i>Saccharomyces cerevisiae</i>, <i>Candida utilis,</i> and <i>Candida albicans</i>. Moreover, the complexes inhibit the development of <i>Escherichia coli</i> and <i>Klebsiella pneumoniae</i>.</p></div

Double template effect in [4+4] Schiff base macrocycle formation: an ESI-MS study

The mechanism of self-assembly of a polynuclear complex of a [4 + 4] Schiff base iminomethylenediphenolate macrocycle [BaCu4(4 + 4)]2+ via a non-macrocyclic dialdehyde intermediate has been followed using ESI-MS of the reaction solutions. Both assembly of the intermediate and Schiffbase condensation with diamine give rise to single products; formation of the intermediate metallacycle is fast but Schiffbase condensation ismuch slower. Both intermediate complex andmacrocyclic product have been structurally characterised

A novel trisprotonated beta-dialdiminate cryptand

A novel trisprotonated beta-dialdiminate cryptan

Nanostructured alpha-Fe2O3 thin films for photoelectrochemical hydrogen generation

We acknowledge PMI2 connect program of the British Council for partly funding the present work

Amides as precursors of imidoyl radicals in cyclisation reactions

Amides have been successfully used as precursors of imidoyl radicals for radical cyclisation. The amides have been converted to imidoyl selanides via reaction with phosgene to yield imidoyl chlorides followed by reaction with potassium phenylselanide. Imidoyl selanides were reacted with tributyltin hydride (Bu3SnH) as the radical mediator with triethylborane or AIBN as initiators to yield imidoyl radicals for cyclisation reactions. Imidoyl radicals have been cyclised onto alkenes to yield 2,3-substituted-indoles and -quinolines and also onto pyrroles and indoles to give bi- and tricyclic heteroarenes

Silver(I) complexes of 9-anthracenecarboxylic acid and imidazoles: synthesis, structure and antimicrobial activity

[Ag2(9-aca)2] (1) (9-acaH = 9-anthracenecarboxylic acid) reacts with a series of imidazoles to give [Ag(imidH)2.3(CH3CN)0.7](9-aca) (3), [Ag6(imidH)4(9-aca)6(MeOH)2] (4), {[Ag(1-Me-imid)2]2[Ag4(9- aca)6]} (5), {[Ag(1-Bu-imid)2]2[Ag4(9-aca)6]} (6) and [Ag(apim)](9-aca)·H2O (7) (imidH = imidazole; 1-Me-imid = 1-methylimidazole; 1-Bu-imid = 1-butylimidazole; apim = 1-(3-aminopropyl)imidazole). The mononuclear complex 3, hexanuclear 4–6, and polymeric 7, were all characterised using X-ray crystallography. While many of the complexes possess excellent in vitro antifungal and antibacterial activities they are, unanimously, more effective against fungal cells. The insect, Galleria mellonella, can survive high doses of the Ag(I) complexes administered in vivo, and a number of the complexes offer significant protection to larvae infected with a lethal dose of pathogenic Candida albicans cells

Regulating Bioactivity of Cu²⁺ Bis-1,10-phenanthroline Artificial Metallonucleases with Sterically Functionalized Pendant Carboxylates

The synthetic chemical nuclease, [Cu­(1,10-phenanthroline)₂]²⁺, has stimulated research within metallonuclease development and in the area of cytotoxic metallodrug design. Our analysis reveals, however, that this agent is “promiscuous” as it binds both dsDNA and protein biomolecules, without specificity, and induces general toxicity to a diversity of cell lineages. Here, we describe the synthesis and characterization of small-molecule metallonucleases containing the redox-active cation, [Cu­(RCOO)­(1,10-phen)₂]⁺, where 1,10-phen = 1,10-phenanthroline and R = −H, −CH₃, −C₂H₅, −CH­(CH₃)₂, and −C­(CH₃)₃. The presence of coordinated carboxylate groups in the complex cation functions to enhance dsDNA recognition, reduce serum albumin binding, and offer control of toxicity toward human cancer cells, Gram positive and negative bacteria, and fungal pathogens. The induction of genomic dsDNA breaks (DSBs) were identified in ovarian adenocarcinoma cells using immunodetection of γ-H2AX. Formate, acetate, and pivalate functionalized complexes induced DSBs in a higher percentage of cells compared with [Cu­(1,10-phen)₂]²⁺, which supports the importance of inner-sphere modification toward enhancing targeted biological application