Synthesis, structure and biological activity of silver(I) complexes containing triphenylphosphine and non-steroidal anti-inflammatory drug ligands.

Two Ag(I) complexes containing triphenylphosphine and non-steroidal anti-inflammatory drug ligands were synthesized and investigated using various spectroscopic studies and single crystal X-ray crystallography. The binding properties of tolfenamic acid, ibuprofen and the two complexes with DNA and BSA were investigated using UV or fluorescence spectroscopy. The results showed that two Ag(I) complexes bound to DNA by the intercalation mode and interacted with BSA using a static quenching procedure.

Silver(I) Complexes with Mefenamic Acid and Nitrogen Heterocyclic Ligands: Synthesis, Characterization, and Biological Evaluation.

Four Ag(I) complexes with mefenamato and nitrogen heterocyclic ligands, [Ag(2-apy)(mef)] (), [Ag(3-apy)(mef)] (), [Ag(tmpyz)(mef)] (), and {[Ag(4,4'-bipy)(mef)](CHCN)(HO)} (), (mef = mefenamato, 2-apy = 2-aminopyridine, 3-apy = 3-aminopyridine, tmpyz = 2,3,5,6-tetramethylpyrazine, 4,4'-bipy = 4,4'-bipyridine), were synthesized and characterized. The interactions of these complexes with BSA were investigated by fluorescence spectroscopy, which indicated that these complexes quench the fluorescence of BSA by a static mechanism. The fluorescence data also indicated that the complexes showed good affinity for BSA, and one binding site on BSA was suitable for the complexes.

Gd(III)-Catalyzed Regio-, Diastereo-, and Enantioselective [4 + 2] Photocycloaddition of Naphthalene Derivatives.

Catalytic asymmetric dearomatization (CADA) reactions have evolved into an efficient strategy for accessing chiral polycyclic and spirocyclic scaffolds from readily available planar aromatics. Despite the significant developments, the CADA reaction of naphthalenes remains underdeveloped. Herein, we report a Gd(III)-catalyzed asymmetric dearomatization reaction of naphthalene with a chiral PyBox ligand via visible-light-enabled [4 + 2] cycloaddition.

Sulfur in Waste-Free Sustainable Synthesis: Advancing Carbon-Carbon Coupling Techniques.

This review explores the pivotal role of sulfur in advancing sustainable carbon-carbon (C-C) coupling reactions. The unique electronic properties of sulfur, as a soft Lewis base with significant mesomeric effect make it an excellent candidate for initiating radical transformations, directing C-H-activation, and facilitating cycloaddition and C-S bond dissociation reactions. These attributes are crucial for developing waste-free methodologies in green chemistry.

Enantioselective Synthesis of Cyclobutane Derivatives via Cascade Asymmetric Allylic Etherification/[2 + 2] Photocycloaddition.

Chiral cyclobutane presents as a popular motif in natural products and biologically active molecules, and its derivatives have been extensively used as key synthons in organic synthesis. Herein, we report an efficient synthetic method toward enantioenriched cyclobutane derivatives. The reaction proceeds in a cascade fashion involving Ir-catalyzed asymmetric allylic etherification and visible-light induced [2 + 2] cycloaddition.

Iridium-Catalyzed Asymmetric Allylic Benzylation with Photogenerated Hydroxy-o-Quinodimethanes.

An iridium-catalyzed asymmetric allylic benzylation of aryl vinyl carbinols under light irradiation is described. 2-Methylbenzophenone derivatives are employed and activated to hydroxy-o-quinodimethanes by an ultraviolet (UV) light. This approach enables asymmetric allylic benzylation with high enantioselectivity (up to 99 % ee) from readily available 2-methylbenzophenones without the utilization of strong bases, and pre-activation or pre-functionalization of the substrates.

Chiral Brønsted Acid-Catalyzed Intramolecular Asymmetric Allylic Alkylation of Indoles with Primary Alcohols.

Herein, chiral Brønsted acid-catalyzed intramolecular asymmetric allylic alkylation of indoles with allylic primary alcohols is described. The allyl alcohols were directly employed as the allylic precursors in this metal-free protocol, without preactivation or any additional activating reagents. This method provides the convenient synthesis of a broad range of functionalized tetrahydrocarbazoles in excellent yields (≤97%) with good enantioselectivity (≤93% ee).

Visible-light induced dearomatization reactions.

Dearomatization reactions provide rapid access to structurally complex three-dimensional molecules from simple aromatic compounds. Plenty of reports have demonstrated their utilities in the synthesis of natural products, medicinal chemistry, and materials science in the last decades. Recently, visible-light mediated photocatalysis has emerged as a powerful tool to promote many kinds of transformations.

Photoredox-Catalyzed Intermolecular Hydroalkylative Dearomatization of Electron-Deficient Indole Derivatives.

Dearomatization of indole derivatives offers a straightforward approach to access diverse indolines. To date, the corresponding dearomative transformations involving electron-deficient indoles are limited. Herein, we report a one-electron strategy for dearomatization of electron-deficient indoles via a photoredox-catalyzed hydroalkylation employing commercially available glycine derivatives as the hydrofunctionalization reagents.

Intermolecular Dearomatization of Naphthalene Derivatives by Photoredox-Catalyzed 1,2-Hydroalkylation.

An intermolecular hydroalkylative dearomatization of naphthalenes with commercially available α-amino acids is achieved via visible-light photoredox catalysis. With an organic photocatalyst, a series of multi-substituted 1,2-dihydronaphthalenes are obtained in good-to-excellent yields. Intriguingly, by tuning the substituents at the C2 position of naphthalenes, formal dearomative [3+2] cycloadditions occur exclusively via a hydroalkylative dearomatization-cyclization sequence.

Asymmetric Dearomatization of Indole Derivatives with N-Hydroxycarbamates Enabled by Photoredox Catalysis.

Dearomatization of indoles provides efficient synthetic routes for substituted indolines. In most cases, indoles serve as nucleophiles. Reported here is an asymmetric dearomatization reaction of indole derivatives that function as electrophiles.

Visible-Light-Promoted Intermolecular Oxidative Dearomatization of β-Naphthols with N-Hydroxycarbamates.

An intermolecular oxidative dearomatization of β-naphthols with N-hydroxycarbamates promoted by visible light was realized by means of photogenerated β-naphthol radical cation intermediates. With a commercially available organic dye, the naphthalenones bearing a fully substituted stereogenic center were obtained with up to 92 % yield under aerobic conditions (26 examples). In addition, the rearrangement of C-O coupling products to C-N coupling compounds could be achieved merely in the presence of Cs CO .

Thermosensitive Chitosan Hydrogels Containing Polymeric Microspheres for Vaginal Drug Delivery.

Thermosensitive hydrogels have increasingly received considerable attention for local drug delivery based on many advantages. However, burst release of drugs is becoming a critical challenge when the hydrogels are employed. Microspheres- (MS-) loaded thermosensitive hydrogels were thus fabricated to address this limitation.

Site-specific covalent attachment of an engineered Z-domain onto a solid matrix: an efficient platform for 3D IgG immobilization.

Immobilized antibodies with oriented and homogeneous patterns are crucial to solid-phase molecular recognition assay. Antibody binding protein-based immobilization can effectively present the desired antibodies. However, steadily installing the stromatoid protein with site-specific attachment manner onto a matrix surface remains to be elucidated.

Immobilization of unraveled immunoglobulin G using well-oriented ZZ-His protein on functionalized microtiter plate for sensitive immunoassay.

Highly efficient protein immobilization is extremely crucial for solid-phase immunoassays. We present a strategy for oriented immobilization of functionally intact immunoglobulin G (IgG) on a polystyrene microtiter plate via iminodiacetic acid (IDA)-Ni(2+) and ZZ-His protein interaction. We immobilized a ZZ-EAP (Escherichia coli alkaline phosphatase)-His fusion protein, which exhibits Fc binding, His tag, and intrinsic AP activities, and analyzed it against the interaction between rabbit IgG anti-horseradish peroxidase (anti-HRP) and its binding partner HRP to investigate the specificity and efficacy of this method.

catena-Poly[[bis-[aqua-(1,10-phenanthroline)lead(II)]-bis-(μ₃-2-hy-droxy-5-sulfonato-benzoato)] acetic acid monosolvate].

In the title compound, [Pb₂(C₇H₄O₆S)₂(C₁₂H₈N₂)₂(H₂O)₂]·CH₃COOH, the seven-coordinate Pb(II) atom is chelated by two N atoms of one 1,10-phenanthroline ligand, four O atoms from three 5-sulfosalicylate dianions and one water O atom. Each dianion serves as a bridging ligand, connecting adjacent Pb(II) atoms into a centrosymmetric polymeric chain extending parallel to [001]. There are π-π inter-actions between the aromatic systems of neighbouring dianions, with plane-to-plane distances of 3.