Synthesis of 1,4-Benzodiazepin-2-ones from Isatins.

Various -protected amino acids were coupled to isatin forming -amino acylisatins. These novel -acylisatins participate in a ring-opening reaction with either alcohols or amines to give the corresponding -glyoxylesters or amides. Upon deprotection, cyclization under basic conditions produces 1,4-benzodiazepin-2-ones bearing ester or amide functionalities at the C5 position.

Ruthenium(II) complexes with photoswitchable and photoejectable ligands.

A ruthenium(II) complex with a photoswitchable arylazopyrazole ligand is reported. Under irradiation a combination of photoisomerisation and photoejection of the ligand occurs.

Synthesis of Indoles through C2-C3 Bond Formation Using Lawesson's Reagent.

Amidophenylglyoxylic esters react with Lawesson's reagent at elevated temperatures, leading to the formation of a diverse array of indole derivatives. This methodology demonstrates broad substrate tolerance and utilizes readily available starting materials. Moreover, this synthetic route is metal-free and environmentally compatible.

Synthesis and Anticancer Activity of 3,4-Diaryl-1,2-dihydro- and 1,2,3,4-Tetrahydroquinolines.

Tetrahydroquinolines are key structures in a variety of natural products with diverse pharmacological utilities and other applications. A series of 3,4-diaryl-5,7-dimethoxy-1,2,3,4-tetrahydroquinolines were synthesized in good yield by reacting 3-aryl-5,7-dimethoxy-2,3-dihydroquinolin-4-ones with different Grignard reagents followed by the dehydration of the intermediate phenolic compounds. Subsequent reduction and deprotection were carried out to achieve the desired tetrahydroquinolone moiety.

Amphetamine-like Deferiprone and Clioquinol Derivatives as Iron Chelating Agents.

The accumulation of iron in dopaminergic neurons can cause oxidative stress and dopaminergic neuron degeneration. Iron chelation therapy may reduce dopaminergic neurodegeneration, but chelators should be targeted towards dopaminergic cells. In this work, two series of compounds based on 8-hydroxyquinoline and deferiprone, iron chelators that have amphetamine-like structures, have been designed, synthesized and characterized.

Probing the Antiaromaticity and Coordination Chemistry of Bowl-Shaped Zinc(II) Norcorrole.

Zinc norcorrole was prepared as its pyridine complex (ZnNc·pyridine) by metalation of freebase norcorrole. The ZnNc·pyridine complex is distinctly bowl-shaped, as demonstrated by both X-ray crystallography and nuclear magnetic resonance (NMR) spectroscopy. NMR spectroscopy showed characteristic ring current deshielding effects, with different magnitudes on either face of the bowl-shaped complex.

Spin crossover of a Fe(II) mononuclear complex induced by intermolecular factors involving chloride and solvent ordering.

Two new salts of a mononuclear tripodal Fe(II) complex were prepared, using ClO and Cl. The ClO sample (1) remained HS at low temperatures, similar to the previously reported BF analogue. Crystallising with the Cl anion (2) led to a markedly different crystal packing arrangement, and engendered SCO activity.

The influence of backbone fluorination on the helicity of α/γ-hybrid peptides.

Peptides that are composed of an alternating pattern of α- and γ-amino acids are potentially valuable as metabolism-resistant bioactive agents. For optimal function, some kind of conformational restriction is usually required to either stabilize the dominant 12-helix, or else to divert the peptide away from this conformation in a controlled way. Herein, we explore stereoselective fluorination as a method for controlling the conformations of α/γ-hybrid peptides.

Ruthenium(II) Complexes of a Xanthene-Spanned Dicarbene Ligand.

Octahedral ruthenium(II) complexes of a xanthene-di(-heterocyclic carbene) ancillary ligand (XdC) have been prepared and structurally characterized. Examples catalyze the transfer hydrogenation of ketones {[Ru(CO)I(,,'-XdC)] () and [Ru(CO)(MeCN)(,,'-XdC)] ()} and the selective electrochemical reduction of CO to CO {[Ru(,'-bpy)(CO)(,,'-XdC)] () at 0.40 V overpotential in MeCN-HO (1 M)}.

Structure of racemic duloxetine hydro-chloride.

Duloxetine hydro-chloride (trade name Cymbalta) is marketed as a single enanti-omer ()--methyl-3-(naphthalen-1-yl-oxy)-3-(thio-phen-2-yl)propyl-am-in-ium chloride, CHNOS·Cl, which is twice as effective as the ()-enanti-omer in serotonin uptake. Here, we report the crystal structure of duloxetine hydro-chloride in its racemic form (space group 2), where it shows significant differences in the mol-ecular conformation and packing in its extended structure compared to the previously reported ()-enanti-omer crystal structure. Mol-ecules of this type, comprising aromatic groups with a single side chain terminated in a protonated secondary amine, are commonly found in active anti-depressants.

Pyrimido[1,2-a]benzimidazoles as inhibitors of oncoproteins ubiquitin specific protease 5 and MYCN in the childhood cancer neuroblastoma.

The MYCN oncogene and histone deacetylases (HDACs) are key driver genes in the childhood cancer, neuroblastoma. We recently described a novel pyridobenzimidazole analogue, SE486-11, which enhanced the therapeutic effectiveness of HDAC inhibitors by increasing MYCN ubiquitination through effects on the deubiquitinase, ubiquitin-specific protease 5 (USP5). Here we describe the synthesis of a novel series of pyrimido[1,2-a]benzimidazole derivatives, and an evaluation of their cytopathic effects against non-malignant and human neuroblastoma cell lines.

How much do molecular shapes matter?

Nifedipine (NIF) molecules (L-type calcium channel antagonists) pack in solvated structures showing strikingly similar patterns, see Jones et al. [Acta Cryst. (2023), B79, 164-175].

Spin Crossover Induced by Changing the Identity of the Secondary Metal Ion from Pd to Ni in a Face-Centered Fe M Cubic Cage.

Discrete spin crossover (SCO) heteronuclear cages are a rare class of materials which have potential use in next-generation molecular transport and catalysis. Previous investigations of cubic cage [Fe Pd L ] constructed using semi-rigid metalloligands, found that Fe centers of the cage did not undergo spin transition. In this work, substitution of the secondary metal center at the face of the cage resulted in SCO behavior, evidenced by magnetic susceptibility, Mössbauer spectroscopy and single crystal X-ray diffraction.

3,4-Bis-O-propargyl-1,2:5,6-di-O-isopropylidene-D-mannitol: a study of multiple weak hydrogen bonds in the solid state.

The title homochiral compound, CHO, 1, was examined by single-crystal X-ray crystallography in order to understand its potential as a synthetic building block, particularly in inter- and intramolecular cyclocondensation reactions. It has also proven to be an excellent model for understanding multiple weak donor-acceptor D-H..

Efficient Reductive Defluorination of Branched PFOS by Metal-Porphyrin Complexes.

Vitamin B (VB) has been reported to degrade PFOS in the presence of Ti citrate at 70 °C. Porphyrin-based catalysts have emerged as VB analogues and have been successfully used in various fields of research due to their interesting structural and electronic properties. However, there is inadequate information on the use of these porphyrin-based metal complexes in the defluorination of PFOS.

Anomalous Structural Evolution and Glassy Lattice in Mixed-Halide Hybrid Perovskites.

Hybrid halide perovskites have emerged as highly promising photovoltaic materials because of their exceptional optoelectronic properties, which are often optimized via compositional engineering like mixing halides. It is well established that hybrid perovskites undergo a series of structural phase transitions as temperature varies. In this work, the authors find that phase transitions are substantially suppressed in mixed-halide hybrid perovskite single crystals of MAPbI Br (MA = CH NH and x = 1 or 2) using a complementary suite of diffraction and spectroscopic techniques.

Synthesis of Alkyne-Substituted Dihydropyrrolones as Bacterial Quorum-Sensing Inhibitors of .

The Quorum-sensing system in is responsible for the pathogenicity and the production of virulence factors and biofilm formation. Dihydropyrrolones were previously found to act as inhibitors of QS-dependent bacterial phenotypes. In this study, a range of dihydropyrrolone (DHP) analogues was synthesized via the lactone-lactam conversion of lactone intermediates followed by the formation of novel acetylene analogues of dihydropyrrolones from brominated dihydropyrrolones via Sonogashira coupling reactions in moderate to high yields.

Unusual Alternating Crystallization-Induced Emission Enhancement Behavior in Nonconjugated ω-Phenylalkyl Tropylium Salts.

The alternating physical properties, especially melting points, of α,ω-disubstituted -alkanes and their parent -alkanes had been known since Baeyer's report in 1877. There is, however, no general and comprehensive explanation for such a phenomenon. Herein, we report the synthesis and examination of a series of novel ω-phenyl -alkyl tropylium tetrafluoroborates, which also display alternation in their physicochemical characters.

Inhibitors of bacterial RNA polymerase transcription complex.

A series of hybrid compounds that incorporated anthranilic acid with activated 1H-indoles through a glyoxylamide linker were designed to target bacterial RNA polymerase holoenzyme formation using computational docking. Synthesis, in vitro transcription inhibition assays, and biological testing of the hybrids identified a range of potent anti-transcription inhibitors with activity against a range of pathogenic bacteria with MICs as low as 3.1 μM.

Hierarchical Spin-Crossover Cooperativity in Hybrid 1D Chains of Fe -1,2,4-Triazole Trimers Linked by [Au(CN) ] Bridges.

Foremost, practical applications of spin-crossover (SCO) materials require control of the nature of the spin-state coupling. In existing SCO materials, there is a single, well-defined dimensionality relevant to the switching behavior. A new material, consisting of 1,2,4-triazole-based trimers coordinated into 1D chains by [Au(CN) ] and spaced by anions and exchangeable guests, underwent SCO defined by elastic coupling across multiple dimensional hierarchies.

Thioether-linked dihydropyrrol-2-one analogues as PqsR antagonists against antibiotic resistant Pseudomonas aeruginosa.

The Pseudomonas quinolone system (pqs) is one of the key quorum sensing systems in antibiotic-resistant P. aeruginosa and is responsible for the production of virulence factors and biofilm formation. Thus, synthetic small molecules that can target the PqsR (MvfR) receptor can be utilized as quorum sensing inhibitors to treat P.

Ultra-Low Molecular Weight Photoswitchable Hydrogelators.

Two photoswitchable arylazopyrozoles form hydrogels at a concentration of 1.2 % (w/v). With a molecular weight of 258.

Synthetic Bilayers on Mica from Self-Assembly of Hydrogen-Bonded Triazines.

This study describes organic thin films prepared under a range of conditions from a model series of bis--alkyl chloro-triazines functionalized with short alkyl chains from ethyl to hexyl. The pure films were characterized using atomic force microscopy (AFM), X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). When cast on mica, these compounds assemble as crystalline sheets made up of a synthetic bilayer along the crystallographic -plane with an internal hydrogen-bonded domain between external alkyl chains.