Products 2b Research Articles

Ultrasound-assisted synthesis of novel Schiff bases from 3-(2-oxo-2H-chromen-3-yl)-1-(4-phenylthiazol-2-yl)-1H-pyrazole-4-carboxaldehyde and their cytotoxicity, apoptosis, cell cycle, molecular docking, and ADMET profiling

With the ultimate goal of discovering new anticancer agents, this study involved the design and synthesis of fifteen novel Schiff bases 4a,b, 5, 6a–d, 7a–e, and 8–10 which contain 3-(2-oxo-2H-chromen-3-yl)-1-(4-phenylthiazol-2-yl)-1H-pyrazole moiety. The synthetic method depended on reaction of 3-(2-oxo-2H-chromen-3-yl)-1-(4-phenylthiazol-2-yl)-1H-pyrazole-4-carboxaldehyde (3) with a series of aromatic and heteroaryl amines under ultrasound irradiation to explore the influence of aromatic and heteroaryl rings on biological activity. The chemical structures of these Schiff bases were fully elucidated using various spectral and elemental analyses. The antiproliferative activities of the Schiff bases were studied by the standard SRB method. Among the new 15 Schiff bases, derivatives 4a,b, 5, and 7b have significant cytotoxic effects against PC3, HepG2, and HCT116 cancer cell lines. These four bioactive Schiff bases significantly increased the late apoptosis of all studied tumor cells. Also, both products 4a and 4b arrested the cell cycle at the G1 phase, while both compounds 5 and 7b arrested the S and G2 phases against PC3 cells. In addition, the products 4a, 4b, 5, and 7b have promising high abilities to arrest the cell cycle at the G2 phase against HepG2 and HCT116 cells. The different substitutions on the aryl ring were the basis for the structure–activity relationship study. The molecular docking study confirmed good binding interactions of these compounds with Cyclin-dependent kinase 8 (CDK-8) receptor, while the absorption, distribution, metabolism, excretion, and toxicity (ADMET) prediction supported that these bioactive products can be promising anticancer agents.

Synthesis, Characterization and Calculations of Linear and Nonlinear Optical Properties of Acrylonitrile Substituted Spirocyclotriphosphazene Derivatives

There methoxy-substituted acrylonitrile compounds (2a, 2b and 2c) were synthesized using method described in the literature. Compounds 3a, 3b and 3c were obtained by using the microwave demethylation method for the first time, then they were reacted with 2,2-dichloro-4,4,6,6-bis[spiro(2′,2″-dioxy-1′,1″-biphenylyl)]-cyclotriphosphazene (DPP) to reach final products 4a, 4b and 4c. The structures of the substituted compounds were determined by elemental analysis, MALDI-TOF, 1H, [Formula: see text]C APT, [Formula: see text]P NMR and FT-IR spectroscopy. In order to investigate the usability potential of the synthesized products 4a, 4b and 4c in optoelectronic devices, we experimentally measured the band gaps and calculated their nonlinear optical properties by Density Functional Theory (DFT) method. Obtained results showed that the introduction of an electronegative substituent (F) or an electropositive substituent (CH[Formula: see text] to the parent compound 4a has minimal impact on the absorption spectra. However, the fluorine-substituted compound 4b exhibits considerably higher values in terms of dipole moment, averaged polarizability, and first-hyper polarizability when compared to compounds 4a and 4c. Calculated values of dipole moment, averaged polarizability, first-hyper polarizability, electronegativity and global hardness of the fluorine-substituted compound 4b were found to be 6.281 (debye), −393.592 (1.4818 × 10[Formula: see text] cm[Formula: see text], 899.857 (8.641 × 10[Formula: see text] cm5/e.s.u), 4.492 (eV) and 1.922 (eV), respectively. These values were the highest in magnitude in comparison to the associated values of 4a and 4c. Overall results indicated that the influence of introducing an electropositive substituent (CH[Formula: see text] to the parent compound 4a, resulting in decreased stability and increased reactivity. Conversely, the introduction of an electronegative substituent (F) to 4a leads to opposite effects.

Who will embrace upward line extension? The role of power distance belief

Upward line extension is a significant strategy for enterprise brand management and market expansion. However, a new status product launched by a non-status brand through upward line extension inevitably forms a competitive relationship with the status product launched by a status brand. Based on the categorization theory, this study explores the influence of status product type (non-extended status product, upward-extended status product) on consumer responses and its potential psychological mechanisms. Furthermore, it examines the moderating role of power distance belief (PDB) in the relationship between status product type and consumer responses. The results indicate that consumers develop lower product evaluations and purchase intentions for upward-extended status products compared to non-extended status products (Studies 1, 2a, 2b, and 2c). Perceived fit and signaling effectiveness mediate the effect of status product type on consumer responses (Study 1). More importantly, PDB moderates the effect of status product type on consumer responses, as high-PDB consumers respond similarly to upward-extended and non-extended status products, whereas low-PDB consumers respond more negatively to upward-extended status products compared to non-extended status products (Studies 2a, 2b, and 2c). Perceived fit and signaling effectiveness mediate the interaction effect between PDB and status product type on consumer responses (Studies 2a and 2b). This study augments the literature on vertical brand extension and PDB, and provides practical guidance for marketers intending to launch upward line extension.

New Cu (I) complexes as catalyst for “click” reaction: An experimental and computational study

In this work, two novel well‐defined Cu (I) complexes of a Schiff base ligand are described. For this purpose, N, N′‐bis (trans‐cinnamaldehyde) ethylenediimine [C20H20N2] (L) and Cu (I) complex of the type [CuC20H20N2)PPh3Cl] (C1) and [Cu(C20H20N2)PPh3Br] (C2) were synthesised. IR, NMR, XRD and TGA analyses were used to characterise these compounds and single‐crystal X‐ray crystallography confirmed the structure of the compounds. The catalytic activity of the synthesised complexes was studied in azide‐alkyne click reaction (AAC) and the best reaction condition was 15 mol% catalyst, 30 min and 45°C in water, which can be considered moderate catalytic activity for the complexes. Material Studio 2017 software was used to obtain the geometry, energy, HOMO and LUMO of all structures by the quantum calculations (module DMol3 and LDA/PWC). The computational results showed catalyst C2 has more reactivity than catalyst C1, and the C1‐catalysed products form faster than the C2‐catalysed products exceptions 4a and 4b. Product 4b (resulting catalyst C2) is formed faster than product (4a).

P-Centred redox reactions of a 1,4-dihydro-1,4-phosphasiline.

Tricyclic 1,4-dihydro-1,4-phosphasilines 3a,b were synthesized from Si(NR2)2-bridged imidazole-2-thione compounds 2a,b. Based on calculated FMOs of 3b, forecasting a possible P-selective P-N bond cleavage reduction, a redox cycle could be established using solutions of P-centred anionic derivative K[4b]. The cycle started with the oxidation of the latter to give the P-P coupled product 5b which could be chemically reduced by KC8 to yield K[4b], again. All new products have been unambiguously confirmed in solution and solid state.

π-Pimer, π-Dimer, π-Trimer, and 1D π-Stacks in a Series of Benzene Triimide Radical Anions: Substituent-Modulated π Interactions and Physical Properties in Crystalline State

π-Pimer, π-Dimer, π-Trimer, and 1D π-Stacks in a Series of Benzene Triimide Radical Anions: Substituent-Modulated π Interactions and Physical Properties in Crystalline State

Regioselective N- versus P-Deprotonation of Aminophosphane Tungsten(0) Complexes

1,2-Bifunctional ligands are rare, in general, which holds especially for those with a P-N linkage. Herein, we report on the synthesis of P-tert-butyl substituted aminophosphane W(CO)5 complexes 3a-f (a: R = R’ = H; b: R = H, R = Me; c: R = H, R’ = ally; d: R = H, R’ = i-Pr; e: R = H, R’ = t-Bu; f: R = R’ = Me) obtained via formal N-H insertion reactions of Li/Cl phosphinidenoid complex 2 into NH bonds of ammonia and different amines. The 1,2-bifunctionality of 3b was addressed in targeted regioselective deprotonation reactions leading to amidophosphane complexes M-4b or M/N(H)Me phosphinidenoid complexes M-5b, respectively (M = Li, K). Remarkable was the observation that reactions of M-4b and M-5b with MeI as the electrophile resulted in the formation of the same product 7b. The constitution of all the compounds has been established by means of NMR and IR spectroscopy and mass spectrometry. Two possible reaction pathways were studied in detail using high-level DFT calculations.

Assembling high nitrogen isomeric energetic molecules via a lithium-mediated concerted [2 + 3] reaction of two diazo compounds

The search for high nitrogen isomeric energetic molecules and comparison of their structure–property relationship are always attractive in the field of energetic materials. In this paper, a novel lithium-mediated concerted [2 + 3] reaction with two diazo compounds has been accomplished which leads to the simultaneous formation of two isomeric cyanotetrazoles (2a and 2b). The cyano group in cyanotetrazoles was further converted to tetrazole or tetrazole N-oxide to form tricyclic heterocyclic products (3a, 3b, 7a, and 7b). The energetic properties of the compounds were studied. A representative compound 3a (Td = 220 °C, D = 9052 m s−1, IS = 13 J, FS = 200 N) has better detonation performances, higher thermal stability and lower mechanical sensitivities than RDX, which is expected to serve as a potential energetic material.

Supramolecular Template-Assisted Catalytic [2+2] Photocycloaddition in Homogeneous Solution

Supramolecular Template-Assisted Catalytic [2+2] Photocycloaddition in Homogeneous Solution

Chiral Bicyclic Imidazole-Catalyzed Direct Enantioselective C -Acetylation of Indolones

Chiral Bicyclic Imidazole-Catalyzed Direct Enantioselective <i>C</i> -Acetylation of Indolones

CO2 trapping of selected N‐heterocyclic vinylidenes with an NBO mechanistic scrutiny by DFT

AbstractTrapping of CO2 is probed by a set of three N‐heterocyclic vinylidene minima, from the azole family, including imidazole (1), 1,2,4‐triazole (2), and tetrazole (3), at M06‐2X/6‐311++G** level of theory. Exothermic adsorption of CO2 over 1, 2, and 3 gives the initial CO2‐complex, 1a, 2a, and 3a, with no transition state (TS). Consequently, carbenic π‐additions to CO2 (within 1a, 2a, and 3a) may give reactant‐like, three‐membered cyclic TSs, which lead to the exothermic formation of 1b &gt; 2b &gt; 3b. Alternatively, CO2 intramolecular reactions within 1a, 2a, and 3a may result in the formation of the product‐like, five‐membered cyclic TSs, which lead to the endothermic formation of unstable side products 1c, 2c, and 3c, which revert to 1a, 2a, and 3a, respectively. Hence, this manuscript focuses on the main CO2 trapped products (1b, 2b, and 3b), and takes advantage of the immense potential of the NBO and AIM data in elucidating their formation provisional mechanisms. Unprecedentedly, contributions of different donor‐acceptor interacting orbitals to the formation of each product are assessed on the basis of their second‐order perturbation stabilization energy (E2) values.

Synthesis and antimicrobial evaluation of novel tris‐thiadiazole derivatives

Abstract1,1′,1″‐(((1,3,5‐triazine‐2,4,6‐triyl)tris(oxy))tris(benzene‐4,1‐diyl))tris(ethan‐1‐one) 1 reacted with extra bromine to afford the corresponding 1,1′,1″‐(((1,3,5‐triazine‐2,4,6‐triyl)tris(oxy))tris(benzene‐4,1‐diyl))tris(2‐bromoethan‐1‐one) 2. Also, reaction of acetophenone derivatives 3 with 5‐amino‐1,3,4‐thiadiazole‐2‐thiol 4 give the 5‐((1‐arylethylidene)amino)‐1,3,4‐thiadiazole‐2‐thiol 5. Compounds 5a–h reacted with 2 in the presences of acetic acid to afford novel 1,1′,1″‐(((1,3,5‐triazine‐2,4,6‐triyl)tris(oxy))tris(benzene‐4,1‐diyl))tris(2‐((5‐((1‐arylethylidene)amino)‐1,3,4‐thiadiazol‐2‐yl)thio)ethan‐1‐one) derivatives 6a–h. Antimicrobial activities of the products were evaluated against five bacterial strains including Streptococcus pneumoniae, Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Serratia marcescens. The antimicrobial results indicated that products 6b, 6d, and 6h had excellent activities as compared to other synthesized products against a variety of bacterial strains. The compounds having Cl and NO2 substituents showed notable inhibition of bacterial growth almost near to Ciprofloxacin as standard.

General and Efficient C–P Bond Formation by Quantum Dots and Visible Light

General and Efficient C–P Bond Formation by Quantum Dots and Visible Light

Nickel-Catalyzed Regiodivergent Asymmetric Cycloadditions of α,β-Unsaturated Carbonyl Compounds

Nickel-Catalyzed Regiodivergent Asymmetric Cycloadditions of α,β-Unsaturated Carbonyl Compounds

Synthesis of Dihydroisoquinoline and Dihydropyridine Derivatives via Asymmetric Dearomative Three-Component Reaction

Synthesis of Dihydroisoquinoline and Dihydropyridine Derivatives via Asymmetric Dearomative Three-Component Reaction

Reverse orientation in the ultrasound-assisted [3 + 2]-cycloaddition reaction of nitrile imines with 3-formylchromone-Meldrum's acid adducts.

The [3 + 2]-cycloaddition reaction of nitrile imines with 2,2-dimethyl-5-[(4-oxo-4H-chromen-3-yl)methylene]-1,3-dioxane-4,6-dione tends to form the reverse-orientation products under ultrasound irradiation in EtOH in the presence of Et3N. Evidence for the structure of product 5b was obtained from single-crystal X-ray analysis.

Photocatalyzed Dual-Oxidative Trifluoromethylthio-Trifluoromethylation of Alkenes with CF 3 SO 2 Na

A novel photocatalyzed trifluoromethylthio-trifluoromethylation of alkenes has been developed, using CF3SO2Na as both CF3 and SCF3 source. This photocatalyzed dual-oxidative strategy, which combine...

Copper (I)–Organic Frameworks for Catalysis: Networking Metal Clusters with Dynamic Covalent Chemistry

Metal clusters exhibit diverse structures, emerging functions, and applications; thus, incorporating clusters into metal–organic frameworks (MOFs) brings tremendous merits. Although the constructio...

C7-Prenylation of Tryptophan-Containing Cyclic Dipeptides by 7-Dimethylallyl Tryptophan Synthase Significantly Increases the Anticancer and Antimicrobial Activities.

Prenylated natural products have interesting pharmacological properties and prenylation reactions play crucial roles in controlling the activities of biomolecules. They are difficult to synthesize chemically, but enzymatic synthesis production is a desirable pathway. Cyclic dipeptide prenyltransferase catalyzes the regioselective Friedel–Crafts alkylation of tryptophan-containing cyclic dipeptides. This class of enzymes, which belongs to the dimethylallyl tryptophan synthase superfamily, is known to be flexible to aromatic prenyl receptors, while mostly retaining its typical regioselectivity. In this study, seven tryptophan-containing cyclic dipeptides 1a–7a were converted to their C7-regularly prenylated derivatives 1b–7b in the presence of dimethylallyl diphosphate (DMAPP) by using the purified 7-dimethylallyl tryptophan synthase (7-DMATS) as catalyst. The HPLC analysis of the incubation mixture and the NMR analysis of the separated products showed that the stereochemical structure of the substrate had a great influence on their acceptance by 7-DMATS. Determination of the kinetic parameters proved that cyclo-l-Trp–Gly (1a) consisting of a tryptophanyl and glycine was accepted as the best substrate with a KM value of 169.7 μM and a turnover number of 0.1307 s−1. Furthermore, docking studies simulated the prenyl transfer reaction of 7-DMATS and it could be concluded that the highest affinity between 7-DMATS and 1a. Preliminary results have been clearly shown that prenylation at C7 led to a significant increase of the anticancer and antimicrobial activities of the prenylated derivatives 1b–7b in all the activity test experiment, especially the prenylated product 4b.

Effect of methyl substituent on the solubility of 1,4-benzoquinone derivatives in n-octanol/water system

The solubility of the compound is a crucial task for new drug design. Quinone is a promising candidate to develop as a new drug. In this research, the synthesis of 1,4-benzoquinone derivatives, that is, 2-(5-bromoamyl)-3,5-dimethyl-1,4-benzoquinone (2a) and 2-(5-bromoamyl)-5-methyl-1,4-benzoquinone (2b) were carried out by decarboxylation and insertion reaction of alkyl bromides. The product 2a and 2b are purified using SiO2 gel column chromatography and analyzed by UV-Visible, FT-IR, and NMR. The yield of 2a is 13.75%, and 2b is 4.04%. The solubility of 2a and 2b, expressed by log P, is measured in the n-octanol/water (3:7 (v/v)) system by the shake flask method. The log P of 2a and 2b are 2.99 and 1.36, respectively. It is showed that the log P of 2a is higher compared to 2b. The presence of two methyl substituents on the quinone ring of 2a supports the increase of hydrophobicity of the compound in the n-octanol/water system.