Synthesis of 6H-Chromeno[4,3-b]quinolin-7-ylphosphonates through Three Component Phosphonylation of Coumarin Carbaldehyde and Their Antimicrobial and Photophysical Properties.

Organophosphorylated coumarin derivatives were synthesized by a three-component reaction of 4-chloro-3-formylcoumarin, aromatic amines, and dialkyl phosphite in the presence of ZnCl2. This process includes the formation of C(sp3)-P and C(sp2)-N bonds in one pot. The modular scope of the reaction allowed rapid access to a variety of 6H-chromeno[4,3-b]quinolin-7-ylphosphonate derivatives in good yields. Furthermore, photophysical studies of the products revealed their stimulating fluorescence properties.

Exploring an Electrochemical Route for Water-Enhanced Oxygenation Reactions Utilizing Nickel Molecular Structures: A Case Study.

Recently, Ni molecular catalysis has been extensively applied in oxygenation reactions. This work is underpinned by the characterization techniques and the discovered instability of the Ni-bipyridine/phenanthroline system, which results in Ni (hydr)oxide production under oxidative conditions. The practical applications of this mechanism by employing a prepared Ni (hydr)oxide-based electrode specifically in the oxygenation of sulfides, achieving noteworthy yields in contrast to noncatalyst control experiments, are explored. Thus, a Ni (hydr)oxide-based material is proposed as a candidate for the true catalyst for sulfide oxidation in the presence of the Ni-bipyridine/phenanthroline system. The findings of this study are expected to stimulate discussion and encourage new viewpoints within the chemical community regarding the potential applications and mechanisms of molecular catalysts in oxidation reactions.

Heteroleptic Silver(I) and Gold(I) N-Heterocyclic Carbene Complexes: Structural Characterization, Computational Analysis, Tyrosinase Inhibitory, and Biological Effects.

Derivatization of (NHC)M-Cl (M = Ag, Au) with selected sulfur donors from the family of dialkyldithiophosphates and bis(2-mercapto-1-methylimidazolyl)borate ligands gave a series of heteroleptic mononuclear complexes. In single-crystal X-ray diffraction analysis, Ag(I) complexes adopted a trigonal planar geometry, while Au(I) complexes are near-linear. TD-DFT and hole-electron analyses of the selected complexes gave insight into the electronic features of the metal complexes. In vitro cellular tests were conducted on the human cancerous breast cell line MCF-7 using 2 and 8. The antibacterial activities of complexes 1, 2, 3, 7, 8, and IPr-Ag-Cl were also screened against Gram-positive (Staphylococcus aureus PTCC 1112) and Gram-negative (Escherichia coli PTCC 1330) bacteria. Antityrosinase and hemolytic effects of the selected compounds were also determined.

Phosphite-imidazole catalyzed N-formylation and N-acylation of amines.

A novel and convenient method for the N-formylation reaction of amines with DMF as a formylating agent has been developed, utilizing a catalytic amount of diethyl phosphite/imidazole. Diethyl phosphite, as a nucleophilic catalyst, plays a significant role in this conversion. The presented method has a broad substrate scope, and various N-formyl products were obtained in good to excellent yields. Moreover, by using DMA instead of DMF, the N-acetylation reaction was also successful. The reaction of o-phenylenediamines with DMF afforded the corresponding benzimidazoles. Furthermore, N-sulfonyl amidines were obtained in good to excellent yields by the reaction of sulfonamides with DMF under similar conditions.

ZnCl2-mediated stereo- and chemoselective synthesis of vinylphosphonates.

A highly chemo- and stereoselective synthesis of diethyl (E)-2-(alkylidene)-2-phosphonoacetonitriles via the Knoevenagel condensation reaction of carbonyl compounds with diethyl cyanomethylphosphonate in the presence of zinc chloride has been achieved. By the presented method, various E-isomers of arylmethylidene phosphonates rather than Horner-Wadsworth-Emmons olefination products were obtained in good to excellent yields. Their E configurations were determined by X-ray diffraction and NMR analyses. In addition, DFT calculations provided insights into the chemo- and stereoselectivity of the reaction.

Chemoselective photocatalytic oxidation of alcohols to aldehydes and ketones by nitromethane on titanium dioxide under violet 400 nm LED light irradiation.

In this study, for the first time, nitroalkanes, especially nitromethane, have been used as electron acceptors for the highly chemoselective oxidation of alcohols in the presence of a TiO2 photocatalyst under 400 nm LED irradiation. The reactions showed excellent selectivity for the production of aldehydes. Interestingly, aldehydes such as benzaldehyde and p-methoxybenzaldehyde are stable under the reaction conditions. In the case of the use of 2-nitropropane and 2-methyl-2-nitropropane, the product imine, which is the result of the reaction of the aldehyde with aliphatic amine, is also obtained.

ZnCl2-Mediated Double Addition of Dialkylphosphite to Nitriles for the Synthesis of 1-Aminobisphosphonates.

In this study, the double addition of dialkylphosphite to nitriles in a ZnCl2/Et3N system is described. The reaction was conveniently and directly used for the synthesis of biologically important 1-aminobisphosphonates (ABPs) from nitriles. The one-pot synthesis of 1-aminobisphosphonates from aldehydes via the in situ generation of nitriles is also described.

One-pot synthesis of biologically active 1,2,3-trisubstituted pyrrolo[2,3-b]quinoxalines through a palladium-catalyzed reaction with internal alkyne moieties.

Synthesis of 2,3-disubstituted 1-alkylpyrrolo[2,3-b]quinoxalines was accomplished through the reaction of 3-chloroquinoxalin-2-amines with internal alkynes in the presence of Pd(OAc)[Formula: see text], NaOAc, and KOtBu in DMSO. This method afforded desired pyrrolo[2,3-b]quinoxalines in 65-92% reaction yields. The minimum inhibition concentration and minimum bactericidal concentration determinations against Micrococcus luteus and Pseudomonas aeruginosa revealed that some of the synthesized compounds showed the same values compared to tetracycline. These compounds could be used in the future research for the development of new antibiotics.

Assessment of spatial distribution of soil heavy metals using ANN-GA, MSLR and satellite imagery.

This study aims to assess and compare heavy metal distribution models developed using stepwise multiple linear regression (MSLR) and neural network-genetic algorithm model (ANN-GA) based on satellite imagery. The source identification of heavy metals was also explored using local Moran index. Soil samples (n = 300) were collected based on a grid and pH, organic matter, clay, iron oxide contents cadmium (Cd), lead (Pb) and zinc (Zn) concentrations were determined for each sample. Visible/near-infrared reflectance (VNIR) within the electromagnetic ranges of satellite imagery was applied to estimate heavy metal concentrations in the soil using MSLR and ANN-GA models. The models were evaluated and ANN-GA model demonstrated higher accuracy, and the autocorrelation results showed higher significant clusters of heavy metals around the industrial zone. The higher concentration of Cd, Pb and Zn was noted under industrial lands and irrigation farming in comparison to barren and dryland farming. Accumulation of industrial wastes in roads and streams was identified as main sources of pollution, and the concentration of soil heavy metals was reduced by increasing the distance from these sources. In comparison to MLSR, ANN-GA provided a more accurate indirect assessment of heavy metal concentrations in highly polluted soils. The clustering analysis provided reliable information about the spatial distribution of soil heavy metals and their sources.

Resolution of enantiomers of novel C2 -symmetric aminobisphosphinic acids via diastereomeric salt formation with quinine.

C2 -symmetric N,N-bis(phosphinomethyl)amines were prepared by the thermal reaction of aromatic aldehydes with ammonia and hypophosphorus acid as previously described. Both enantiomers of C2 -symmetric N,N-bis(phosphinomethyl)amine were obtained in a high enantiomeric purity through the diastereomeric salt formation with (-)-quinine, and subsequent fractional crystallization. X-ray crystallographic analysis of one of the diastereomeric salts clearly revealed that (-)-quinine could be an efficient resolving agent for obtaining the single enantiomer (R,R)-N,N-bis(phosphinomethyl)amine.

Inhibition of cytotoxic self-assembly of HEWL through promoting fibrillation by new synthesized α-hydroxycarbamoylphosphinic acids.

The main objective of the present study is to investigate the potency of new synthesized hydroxycarbamoyl phosphinic acid derivatives in modulating cytotoxic fibrillogenesis of hen egg white lysozyme (HEWL), as a common model in protein aggregation studies. Hydroxycarbamoyl phosphinic acid derivatives were prepared by the reaction of α-hydroxyalkylphosphinic acids with isocyanates (or isothiocyanates) in the presence of trimethylsilyl chloride (TMSCl). The designed process involves the condensation reaction leading to formation of new C sp2-P bond formation. The synthesis and purity of novel designed compounds were confirmed by NMR, LC-MS, and HPLC techniques. A range of experiments, including thioflavin T (ThT) and 8-anilino-1-naphthalenesulfonic acid (ANS) fluorescence assays, Congo red binding measurement, atomic force microscopy imaging, MTT-based cell viability and hemolysis assays were employed to investigate anti-amyloidogenic effects of tested compounds. The obtained results demonstrate that these compounds are able to significantly modulate the self-assembly process of HEWL via shortening of nucleation phase leading to the acceleration of fibrillation and appearance of very large and thick fibrils with decreased surface hydrophobicity and cytotoxicity. Based on ANS binding data, we suggest that increased exposure of hydrophobic patches of oligomeric species is the possible mechanism by which tested compounds promote self-assembly process of HEWL. Fluorescence anisotropy and molecular docking studies indicate the interaction of both synthesized compounds with HEWL, and more specifically with residues that are situated in the highly aggregation-prone ß-domain region of protein. This study unveils the potential of hydroxyalkylphosphinic acids as modulators of amyloid fibrillation highlighting these compounds as a promising approach for targeting protein aggregates associated with neurodegenerative diseases.

Synthesis of α-oxycarbanilinophosphonates and their anticholinesterase activities: the most potent derivative is bound to the peripheral site of acetylcholinesterase.

A novel method has been developed for the synthesis of α-oxycarbanilino phosphonates through a reaction of α-hydroxyphosphonates with isocyanate under microwave irradiation. The synthesized compounds were evaluated for their acetylcholinesterase (AChE) inhibition potency through IC(50) determination. Molecular modelling studies suggest that the most potent inhibitor (compound 4h, IC(50) = 6.36 µM) is bound to the peripheral site of AChE, which suggests that it decreases the catalytic activity not through binding to the active site but through blocking the entrance of the active site gorge. This puts forward the potential of compound 4h and its derivatives to be used in the design of dual inhibitors: inhibition of the catalytic activity of AChE and of amyloid ß aggregation.

Stereoselective synthesis of vinylphosphonates through aromatic aza-Claisen rearrangement of α-aminophosphonates.

A novel and convenient approach for the synthesis of vinyl phosphonates has been developed, utilizing an aromatic aza-Claisen rearrangement of ß,γ-unsaturated α-aminophosphonates. The synthetic utility of this method was further examined in a gram-scale synthesis. The DFT calculations have provided insights into the basis of the reaction mechanism.

Practical photocatalytic and sonophotocatalytic reduction of nitroarenes in water under blue LED irradiation using ß-CD modified TiO2 as a green nest photocatalyst.

Photocatalysis using natural photosynthesis is a green technology that is gaining popularity in a number of industries due to its potential for environmental applications and the use of solar energy. Focus is being placed on using inexpensive materials and light-emitting diodes (LEDs) of various wavelengths in photocatalytic reactions in order to improve the performance of solar-driven photocatalysts at a lower cost. In this study, a scalable, highly efficient photocatalytic and sonophotocatalytic method was investigated for the reduction of nitro-compounds by a water/titania/ß-cyclodextrin system under sunlight and blue LED irradiation, using sodium sulfide as a sacrificial electron donor. ß-Cyclodextrin, chemically bound to TiO2 nanoparticles as an encapsulating agent, hosted nitro compounds in aqueous media and formed an inclusion complex. In addition, this method was used to successfully carry out one-pot reduction-amidation of nitroarene compounds in the presence of acetic anhydride. Interestingly, it was found that ultrasound has a synergistic effect on photocatalytic reduction and considerably reduces the duration time. In this regard, a fast, practical sonophotocatalytic reduction of nitroarenes was carried out in an ultrasound bath.

Organic Phase-Soluble Nanomagnetically Cationic Phospholipid: Synthesis, Characterization, and In Vitro Transfection Activity.

The presented work describes the synthesis and characterization of a novel magnetic cationic phospholipid (MCP) system with a stable dopamine anchor as well as its transfection activity study. The synthesized architectural system increases the biocompatibility of iron oxide and promises applications of magnetic nanoparticles in living cells. The MCP system is soluble in organic solvents and can be easily adapted to prepare magnetic liposomes. We created complexes with liposomes containing MCP and other functional cationic lipids and pDNA as gene delivery tools, which possessed the ability to enhance the efficiency of transfection, particularly the process of interaction with cells by inducing a magnetic field. The MCP is able to create iron oxide nanoparticles and has the potential for the materials to prepare the system for site-specific gene delivery with the application of an external magnetic field.

Correction to "Homobimetallic Au(I)-Au(I) and Heterotrimetallic Au(I)-Fe(II)-Au(I) Complexes with Dialkyldithiophosphates and Phosphine Ligands: Structural Characterization, DFT Analysis, and Tyrosinase Inhibitory and Biological Effects".

[This corrects the article DOI: 10.1021/acsomega.3c00645.].

Homobimetallic Au(I)-Au(I) and Heterotrimetallic Au(I)-Fe(II)-Au(I) Complexes with Dialkyldithiophosphates and Phosphine Ligands: Structural Characterization, DFT Analysis, and Tyrosinase Inhibitory and Biological Effects.

The role of bridging and terminal ligand electronic and steric properties on the structure and antiproliferative activity of two-coordinated gold(I) complexes was investigated on seven novel binuclear and trinuclear gold(I) complexes synthesized by the reaction of either Au2(dppm)Cl2, Au2(dppe)Cl2, or Au2(dppf)Cl2 with potassium diisopropyldithiophosphate, K[(S-OiPr)2], potassium dicyclohexyldithiophosphate, K[(S-OCy)2], or sodium bis(methimazolyl)borate, Na(S-Mt)2, which afforded air-stable gold(I) complexes. In 1-7, the gold(I) centers adopt a two-coordinated linear geometry and are structurally similar. However, their structural features and antiproliferative properties highly depend upon subtle ligand substituent changes. All complexes were validated by 1H, 13C{1H}, 31P NMR, and IR spectroscopy. The solid-state structures of 1, 2, 3, 6, and 7 were confirmed using single-crystal X-ray diffraction. A density functional theory geometry optimization calculation was used to extract further structural and electronic information. To investigate the possible cytotoxicities of 2, 3, and 7, in vitro cellular tests were carried out on the human cancerous breast cell line MCF-7. 2 and 7 show promising cytotoxicity.

One-pot synthesis of 1,2,3-triazoles from boronic acids in water using Cu(II)-ß-cyclodextrin complex as a nanocatalyst.

We report here the one-pot synthesis of 1,2,3-triazoles of arylboronic acids in water. An efficient method has been developed for the synthesis of 1,2,3-triazoles via a one-pot reaction of an arylboronic acid with sodium azide in the presence of Cu(2)-ß-CD (CD = Cyclodextrin) as a nanocatalyst in water followed by a click cyclization reaction with an alkyne at room temperature in air without any additives. This method is simple, rapid, and high yielding.

Synthesis and inhibitory activity of ureidophosphonates, against acetylcholinesterase: pharmacological assay and molecular modeling.

A novel method has been developed for the synthesis of 1-ureidophosphonates through a three components condensation of aldehyde with amine and diethylphosphite in the presence of sulfanilic acid as catalyst followed by subsequent reaction of the product with isocyanate. This method is easy, rapid, and good yielding. The anticholinesterase (AChE) activities (inhibition potency through IC(50)) of newly synthesized 1-ureidophosphonates were also investigated. The activities of the synthesized compounds toward the enzyme AChE were determined and compared in terms of their molecular structures and it was found, through molecular docking simulations, that the most potent derivative (compound 3i) inhibited the enzyme through binding to the peripheral anionic site (PAS) and not to its acylation site (A site).