Nickel(II)/Salox-Catalyzed Enantioselective C-H Functionalization.

Recently, nickel catalysts have garnered considerable attention for their efficacy and versatility in asymmetric catalysis, attributed to their distinctive properties. However, the use of cost-effective and sustainable divalent nickel catalysts in C-H activation/asymmetric alkene insertion poses significant challenges due to the intricate control of stereochemistry in the transformation of the tetracoordinate C-Ni(II) intermediate. Herein, we report a Ni(II)-catalyzed enantioselective C-H/N-H annulation with oxabicyclic alkenes.

5-Aminopyrazole Dimerization: Cu-Promoted Switchable Synthesis of Pyrazole-Fused Pyridazines and Pyrazines via Direct Coupling of C-H/N-H, C-H/C-H, and N-H/N-H Bonds.

A Cu-promoted highly chemoselective dimerization of 5-aminopyrazoles to produce pyrazole-fused pyridazines and pyrazines is reported. The protocol generates switchable products via the direct coupling of C-H/N-H, C-H/C-H and N-H/N-H bonds, with the merits of broad substrate scope and high functional group compatibility. Gram-scale experiments demonstrated the potential applications of this reaction.

Synthesis of Some Thiazolyl and Oxazolyl Quinazoline Derivatives as Potential Anti-Microbial Agents.

Introduction: Quinazoline holds significant importance in pharmaceutical chemistry, which is included in a range of drugs, clinical contenders, and bioactive compounds. N-contain-ing heterocyclic compounds of quinazoline have a wide and distinct range of biopharmaceutical activities.

Methods: A series of newly synthesized heterocyclic compounds, namely, N-(4-substituted ben-zylidene)-2-(2-aminothiazol-4-yl)-6-methylquinazolin-3(4H)-amines (3a'-3e') and N-(4-substi-tuted benzylidene)-2-(2-aminooxazol-4-yl)-6-methylquinazolin-3(4H)-amines (3a-3e), were synthesized starting from 6-methylquinazolin-3(4H)-amine and 4-substituted benzaldehyde and their antibacterial and antifungal properties were evaluated.

Selected Ion Extraction of Peptides with Heavy Isotopes and Hydrogen Loss Reduces the Type II Error in Plasma Proteomics.

Naturally occurring peptides display a wide mass distribution after ionization due to the presence of heavy isotopes of C, H, N, O, and S and hydrogen loss. There is a crucial need for sensitive methods that collect as much information as possible about all plasma peptide forms. Statistical analysis of the delta mass distribution of peptide precursors from MS/MS spectra that were matched to 63,077 peptide sequences by X!TANDEM revealed Gaussian peaks representing heavy isotopes and hydrogen loss at integer delta mass values of -3, -2, -1, 0, +1, +2, +3, +4, and +5 Da.

Interaction Mechanisms of Cold Atmospheric Plasmas with HIV Capsid Protein by Reactive Molecular Dynamics Simulation.

In recent years, plasma medicine has developed rapidly as a new interdisciplinary discipline. However, the key mechanisms of interactions between cold atmospheric plasma (CAP) and biological tissue are still in the exploration stage. In this study, by introducing the reactive molecular dynamics (MD) simulation, the capsid protein (CA) molecule of HIV was selected as the model to investigate the reaction process upon impact by reactive oxygen species (ROS) from CAP and protein molecules at the atomic level.

Inorganic-organic hybrid nanoparticles with carbonate-triggered emission-colour-shift.

(Eu[PTC])(Eu[TREN-1,2-HOPO]) inorganic-organic hybrid nanoparticles (IOH-NPs) contain Eu, tris[(1-hydroxy-2-oxo-1,2-dihydropyridine-6-carboxamido)ethyl]amine (TREN-1,2-HOPO) and perylene-3,4,9,10-tetracarboxylate (PTC). The IOH-NPs are prepared in water and exhibit a rod-type shape, with a length of 60 nm and a diameter of 5 nm. Particle size and chemical composition are examined by different methods (SEM, DLS, FT-IR, TG, C/H/N analysis).

Electrochemistry-enabled Ir-catalyzed C-H/N-N bond activation facilitates [3+2] annulation of phenidones with propiolates.

A mild and efficient [3+2] annulation of phenidones with propiolates has been developed to access -substituted indole alkylamides, enabled by merging electrochemistry with iridium catalysis using an undivided cell at room temperature. The mechanistic studies have confirmed that the electrochemically mediated catalytic cycle of Ir-Ir-Ir exhibits enhanced efficiency, mild reaction conditions, and unconventional selectivity.

Tailored Functionalization of Plasmonic AgNPs/C:H:N:O Nanocomposite for Sensitive and Selective Detection.

We report here on the development of tailored plasmonic AgNPs/C:H:N:O plasma polymer nanocomposites for the detection of the pathogenic bacterium Borrelia afzelii, with high selectivity and sensitivity. Silver (Ag) nanoparticles, generated by a gas aggregation source, are incorporated onto a C:H:N:O plasma polymer matrix, which is deposited by magnetron sputtering of a nylon 6.6.

Programmable Synthesis of Cationic Azaperylenes via Rh(III)-Catalyzed Multiple C-H/N-H Bonds Activation and Annulation.

Rh(III)-catalyzed dual N-H and triple C-H activation/(4 + 2) annulation of 2-aryl-2,3-dihydro-1-perimidines and alkynes has been disclosed to construct 4,5,14,15-tetrasubstituted cationic azaperylenes with high yields (up to 95%) and broad scope. Tandem (4 + 2) annulation of 1-perimidines with vinylene carbonate and alkynes affords 4,5-disubstituted azaperylene salts, and -alkynyl 1-perimidines undergo an intra- and intermolecular annulation cascade to give 4,5,14-trisubstituted targets. Most of the intermediates were detected by ESI-MS, indicating a convincible mechanism including three possible paths.

Green Synthesis and Characterization of Silver Nanoparticles Using Extracts to Investigate Their Antibacterial Potential.

Background And Purpose: Antimicrobial resistance (AMR) has emerged as a significant global concern. To combat this growing threat, various strategies have been employed, including the use of plant extracts and the biosynthesis of nanoparticles (NPs). The current study was designed to evaluate the phytochemical analysis of ginger () extracts, characterize the silver nanoparticles (AgNPs) and to see their antibacterial potentials against multi-drug resistant (MDR) bacterial strains.

Diagnosis, treatment, and follow-up of patients with hypophosphatasia.

Introduction: Hypophosphatasia is a rare inherited systemic metabolic disorder, with an estimated prevalence in the severe forms of the disease of 1/100.000-1/300.000, that affects the typical architecture of bone, leading to defective mineralization during growth and remodeling.

Ru(II)-Catalysed Highly Regioselective C6 C-H/N-H Annulation of Indole-7-carboxamides with Alkynes for the Synthesis of Pyrrolo[3,2-h]isoquinolin-9-ones.

We disclosed an efficient protocol for regioselective C6 C-H/N-H activation/annulation reaction of indole-7-carboxamides with alkynes to synthesize highly substituted pyrrolo[3,2-h]isoquinolin-9-one derivatives. Under optimized reaction conditions, electron-deficient and electron-rich internal alkynes reacted efficiently with various indole-7-carboxamides to deliver desired products in good to excellent yields. The synthetic utility of the product is demonstrated by its selective oxidation to the corresponding isatin derivative.

The Relationship Between Spin Crossover (SCO) Behaviors, Cation and Ligand Motions, and Intermolecular Interactions in a Series of Anionic SCO Fe(III) Complexes with Halogen-Substituted Azobisphenolate Ligands.

To investigate the halogen substitution effect on the anionic spin crossover (SCO) complexes, azobisphenolate ligands with 5,5'-dihalogen substituents from fluorine to iodine were synthesized, and their anionic Fe complexes , , , and were isolated. The temperature dependence of magnetic susceptibility and crystal structure revealed that , , and are all isostructural and exhibit SCO with the rotational motion of the cation and ligands, whereas shows incomplete SCO. Note that and showed irreversible and reversible cooperative SCO transitions, respectively.

Formation of Planar π-Conjugated Sheets in Cocrystals of Bis(iodoethynyl)pyridines and Bipyrimidylalkynes: Cooperative C-H···N Hydrogen Bonds and sp-C-I···N Halogen Bonds.

The cocrystallization of the ditopic halogen bond donors 2,5-, 2,6-, 3,5-bis(iodoethynyl)pyridines with the dipyrimidyls 1,2-bis(5-pyrimidyl)ethyne and 1,4-bis(5-pyrimidyl)butadiyne is explored. The cocrystal components have complementary shapes and functional groups so that the noncovalent C-I···N halogen bonding and C-H···N hydrogen bonding interactions are complementary resulting in 1:1 cocrystals with the ditopic halogen bond accepting bipyrimidyls. The cocrystals feature π-stacked planar sheets of alternating bis(iodoalkynes) and bipyrimidyls held together in one direction by I···N halogen bonds and in the roughly orthogonal direction by pyridine-pyridine and pyrimidine-pyrimidine C-H···N hydrogen bonds.

Cp*Co(III)-catalyzed synthesis of isoquinolones controlled annulation of primary arylamides with internal alkynes.

In this study, we present the first cobalt(III)-catalyzed direct synthesis of isoquinolones from readily available primary arylamides and internal alkynes through a controlled oxidative C-H/N-H annulation reaction. This innovative protocol eliminates the need for expensive transition metal salts and external auxiliaries, producing the desired mono-annulated product exclusively while accommodating a wide range of substrates. Preliminary mechanistic studies highlight the critical role of copper oxide in facilitating the transformation.

Cobalt-Catalyzed Regioselective C8-H Sulfoxamination of 1-Naphthylamine Derivatives with NH-Sulfoximines.

A simple cobalt-catalyzed, picolinamide-directed C8-H sulfoxamination of 1-naphthalamides with NH-sulfoximines has been developed. This cross-dehydrogenative C-H/N-H coupling reaction offers a facile route to N-arylated sulfoximines, exhibiting high yields, a broad substrate scope, and excellent functional group tolerance and scalability.

Diverse Self-Assembled Molecular Architectures Promoted by C-H···O and C-H···Cl Hydrogen Bonds in a Triad of α-Diketone, α-Ketoimine, and an Imidorhenium Complex: A Unified Analysis Based on XRD, NEDA, SAPT, QTAIM, and IBSI Studies.

X-ray structural elucidation, supramolecular self-assembly, and energetics of existential noncovalent interactions for a triad comprising α-diketone, α-ketoimine, and an imidorhenium complex are highlighted in this report. Molecular packing reveals a self-assembled 2D network stabilized by the C-H···O H-bonds for the α-diketone (benzil), and the first structural report of Brown and Sadanaga stressing on the prevalence of seems to be an oversimplified conjecture. In the α-ketoimine, the imine nitrogen atom undergoes intramolecular N···H interaction to render itself inert toward intermolecular C-H···N interaction and exhibits two types of C-H···O H-bonds in consequence to generate a self-assembled 2D molecular architecture.

Homogeneity analysis of medicine tablets by laser induced breakdown spectroscopy combined with multivariate methods.

Pharmaceutical tablets need to have a homogenous chemical structure, especially in cases where the patient may divide the tablet in half prior to consumption. This work aims to demonstrate the viability of using laser induced breakdown spectroscopy (LIBS) for analyzing the homogeneity and determining the chemical composition of losartan potassium tablets. This was accomplished by obtaining the spectra of 10 tablet points in 30 successive laser pulses, which revealed four main peaks (C, H, N, and O) as well as a high concentration of calcium and potassium in the core tablets and titanium in the coating-all of which are excellent analytical objectives for LIBS.

A novel AAV9-dual microRNA-vector targeting in the hippocampus as a treatment for mesial temporal lobe epilepsy.

Mesial temporal lobe epilepsy (mTLE) is the most prevalent type of epilepsy in adults. First and subsequent generations of anti-epileptic therapy regimens fail to decrease seizures in a large number of patients suffering from mTLE, leaving surgical ablation of part of the hippocampus as the only therapeutic option to potentially reach seizure freedom. GluK2 has recently been identified as a promising target for the treatment of mTLE using gene therapy.

Molecular Association and Reactivity of the Pyridine Dimer Cation.

A recent experimental report has identified the formation of the C-N hemibonded pyridine dimer cation following vacuum ultraviolet near-threshold photoionization [, , 12, 4936-4943]. Herein, the dynamics and consequent reactivity of the pyridine dimer cation were investigated employing Born-Oppenheimer molecular dynamics (BOMD) simulations. An antiparallel π-stacked pyridine dimer in the neutral ground state is transformed into a noncovalently interacting C-H···N hydrogen-bonded structure which can lead to proton transfer in the cationic state.

Effect of graphene electrode functionalization on machine learning-aided single nucleotide classification.

Solid-state nanogap-based DNA sequencing with a quantum tunneling approach has emerged as a promising avenue due to its potential to deliver swift and precise sequencing outcomes. Nevertheless, despite significant progress, experimentally achieving single base resolution with a high signal-to-noise ratio remains a daunting challenge. In this work, we have utilized a machine learning (ML) framework coupled with the quantum transport method to assess and compare the nucleotide identification performance of graphene nanogaps functionalized with four different edge-saturating entities (C, H, N, and OH).

Assessment of amoxicillin (AMX) removal from aqueous medium through Rhapis-based bioretention system.

Antibiotics can be effectively removed from wastewater using constructed wetlands (C.W.s).

Palladium/norbornene-catalyzed C-H/N-H cycloaddition of carbazoles with 2-halobenzoic acid derivatives.

An example of palladium/norbornene-catalyzed C-H/N-H cycloaddition of carbazoles with 2-bromobenzoic acids is presented, in which a collection of important carbazoles is expeditiously obtained. Derivatives, including acyl halides, α-oxocarboxylic acids, anhydrides, and even amides, are all allowed. Preliminary mechanistic studies reveal that a rare six-membered spiropalladacycle is involved.