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An efficient palladium‐catalyzed annulation of 3‐arylquinazolinones with mono and double alkyne insertion was developed for the synthesis of fused quinazolinone derivatives in 43–80 % yields. A notable effect was observed in product yield, when bases/additives were modulated. The reaction mechanism is believed to proceed through C−X cleavage/alkyne insertion/1,4‐Pd migration and C−H annulation in a one‐pot manner. [ABSTRACT FROM AUTHOR]

Excessive emission of CO2 has caused a critical greenhouse effect that is emerging as a major threat to the environment. Electrocatalytic reduction of CO2 is an advanced technology where chemically inert CO2 is reduced and can be used to produce value-added fuels or chemicals. In this work, the electrocatalytic performance of a single Cu atom embedded in a MoS2 monolayer with a sulfur vacancy for the electroreduction of CO2 is studied using density functional theory (DFT) with dispersion correction. The single Cu atom is stably located in the sulfur vacancy of the MoS2 monolayer. The multiple pathways explored here involve proton–electron pair transfer in the CO2 reduction reaction (CO2RR) to yield a variety of C1 products, such as HCOOH, CO, CH3OH and CH4. These pathways were examined using the corresponding free energy profiles and overpotentials. Among the different C1 products, CH4 formation is more favored via the following optimized pathway: *CO2 → *OCHO → *OCHOH → *OCH2OH → *OCH2 → *OCH3 → *OHCH3 → *OH + CH4 → H2O. The MoS2 monolayer with embedded Cu has enhanced CO2RR activity with an appreciably low overpotential compared to pristine MoS2. This study provides a deep understanding of the structure–reaction relationships and various mechanistic pathways of the CO2RR, and could aid in the design of high-performance single-atom electrocatalysts. [ABSTRACT FROM AUTHOR]

Protein engineering by directed evolution is time-consuming. Hence, in silico techniques like FoldX-Yasara for ∆∆G calculation, and SNPeffect for predicting propensity for aggregation, amyloid formation, and chaperone binding are employed to design proteins. Here, we used in silico techniques to engineer BDNF-NTF3 interaction and validated it using mutations with known functional implications for NGF dimer. The structures of three mutants representing a positive, negative, or neutral ∆∆G involving two interface residues in BDNF and two mutations representing a neutral and positive ∆∆G in NGF, which is aligned with BDNF, were selected for molecular dynamics (MD) simulation. Our MD results conclude that the secondary structure of individual protomers of the positive and negative mutants displayed a similar or different conformation from the NTF3 monomer, respectively. The positive mutants showed fewer hydrophobic interactions and higher hydrogen bonds compared to the wild-type, negative, and neutral mutants with similar SASA, suggesting solvent-mediated disruption of hydrogen-bonded interactions. Similar results were obtained for mutations with known functional implications for NGF and BDNF. The results suggest that mutations with known effects in homologous proteins could help in validation, and in silico directed evolution experiments could be a viable alternative to the experimental technique used for protein engineering. [ABSTRACT FROM AUTHOR]

• The (E)-2-hydroxy-5-(((4-(N-(thiazol-2-yl) sulfamoyl) phenyl) imino) methyl) benzoic acid is an optical material, because it is showing good fluorescence spectrum. • Electronic properties, FMO and MEP were analysed by using different solvents. • Using the DLPNO-CCSD(T), the most stable dissociation energies are confirmed in 5FSATH-water complex. • The active sites and interaction were determined using ELF, LOL, and RDG. • The antimicrobial activity confirms our synthesized compound moderate activity. The molecular docking experiment showed 5FSATH had an extremely high binding affinity score. The Schiff base (5FSATH) was synthesized and characterized by different experimental techniques. In the context of local energy decomposition analysis (LED), the binding energy of 5FSATH-water interaction is determined to be -15.63 kcal/mol, while the bond distance between the two objects is measured to be 1.9781 A°. The absorption spectrum was recorded using different solvents like DMSO, water, and chloroform. The experimental absorption spectrum wavelengths 206, 220, and 300 nm, were recorded from DMSO solvent. In the emission (fluorescence) spectrum we observed three different wavelengths such as 352, 510, and 609 nm. For the calculated NMR spectrum, used the standard GIAO method and DMSO as the solvent. The HOMO-LUMO analysis indicates the charge transfer within the molecule, it is calculated by different solvents. NBO confirms the synthesized compound stability, hyper conjugative interaction, and charge delocalization. To test for antibacterial and antifungal activity, an agar disc well diffusion method is utilized. Synthesized compound tested against Escherichia coli, Candida albicans, Staphylococcus aureus, and Streptococcus pneumoniae microorganisms. Amoxicillin was used as the reference drug for testing antibacterial and antifungal activity. According to the findings of the antimicrobial activity, the result of the molecular docking experiment showed that the compound 5FSATH had an extremely high binding affinity score. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel class of spirooxindolopyrrolidines was synthesized employing cycloaddition methodology. • Spiro compounds were achieved in good yields and assigned by spectroscopic analysis. • In vitro antimicrobial activity against multi-drug resistant bacteria and fungi. • Trifluoromethoxy substituted spiro compound 4b displayed significant antimicrobial activity. Infectious diseases are a major public health concern worldwide and a leading cause of morbidity and mortality. Spirooxindolopyrrolidine moiety is attractive in this connection, because this structural unit predominates in many biologically relevant natural alkaloids and displayed multifarious biological profiles including antimicrobial activities. In present study, we have synthesized new class of spirooxindolopyrrolidine hybrid heterocycles employing multicomponent cycloaddition methodology. Compound thus synthesized were evaluated for their antimicrobial activity against common microbial pathogens. Of the compounds 4a-d , the compound 4b bearing trifluoromethoxy unit on the oxindole ring exhibited significant antimicrobial activity with an inhibition range from 7.00 ± 0.15 to 20.00 ± 0.08 mm and MIC value from 8.00 to >256.00 μg/mL against selected microbial pathogens. Hence, the compound 4b was a potential candidate to compacting infectious diseases causing microbial pathogens. The overall results of this study indicated that compound 4b has higher potential activities against both multidrug-resistant bacteria and fungal pathogens. Further research studies are needed to fully understand their medicinal properties of new hybrid heterocycles that are being developed in our laboratory for potential therapeutic development to treat various diseases caused by microbial pathogens. [ABSTRACT FROM AUTHOR]

[Display omitted] • Absorption studies of (E)-2-hydroxy-5-(((4-sulfamoyl phenyl) imino) methyl) benzoic acid with metal clusters (Pt/Ni/Ru) in gas phase and water phase are investigated. • The adsorption energies of 5FSANI-Pt2-Ru (water medium) cluster are the highest absorption energy. • The studies ELF, LOL and RDG were conducted. • In FMO analysis, we observed very low energy gap values. The adsorption of (E)-2-hydroxy-5-(((4-sulfamoyl phenyl) imino) methyl) benzoic acid (5FSANI) on various metal clusters and chemical descriptors was investigated on the basis of the solvation effects by using frontier molecular orbital (FMO), molecular electrostatic potential (MEP), and wave function analyses. In this study two basis sets (mixed basis set) such as cc-pVDZ and Lan-L2DZ with B3LYP functional level were used. The Lan-L2DZ basis set was used for metal atoms and cc-pVDZ basis set was used for other atoms like, C, H, N, S, and O respectively. The adsorption energy of 5FSANI-Pt2-Ru (water) cluster was found to be the highest (−170.78 kcal/mol), whereas the adsorption energy of 5FSANI-Ru3 (water) cluster was found to be the lowest (−11.94 kcal/mol). After the addition of the metal clusters, 5FSANI became more electrophilic, as evidenced by the higher electrophilicity index of all metal-drug systems. The results of this study indicated that the solvents had stronger negative solvation energies. The investigation of non-covalent contacts showed the considerable inter and intra-molecular interactions. Studies such as electron localized function (ELF), localized orbital locator (LOL), and average localized ionization energy (ALIE) confirmed the electron localization and delocalization energies. The metal frontier molecular orbital and the molecular electrostatic potential of the clusters were calculated by using the density functional theory (DFT) method. [ABSTRACT FROM AUTHOR]

The significance of orientational and (ro)vibrational excitations on the K( 2 S) + H 2 ( X 1 Σ g + ) reaction dynamics is presented here by performing the exact time-dependent wavepacket calculations using the Coriolis coupling (CC) approach. Employing the new accurate ab initio ground electronic surface 1 2 A ′ reported by Yuan et al. (2018), the dynamical quantities such as integral cross sections and thermal rate constants are computed within the CC and CS (centrifugal sudden) methods. All partial wave contributions of J (total angular momentum) up to 90 are required to get the convergence in dynamical results up to the collision energy of 3.5 eV. The present study attests that the ground and first vibrational level dynamics is insignificant. For v = 2 , the reaction probability is monotonically increasing, followed by the onset noted near 1.25 eV, as a function of collision energy up to 3.5 eV. Further, the kinematic effects (replacing H by D atom) on the title system is also performed and found that the KH product formation is more favored than the KD product via HD depletion path. [ABSTRACT FROM AUTHOR]

• Novel biologically active N -tosylated benzimidazole was prepared in good yield. • Structural elucidation was done by NMR and single crystal X-ray diffraction analysis. • Compound was determined by computational study. • Compound displayed significant antioxidant and TB activities. • A docking simulation was performed for the synthesized compound. Synthesis of 2-(diethoxymethyl)-1-tosyl-1H-benzo[ d ]imidazole 5 in excellent yield was achieved from 2-(1-ethoxypropyl)-1H-benzo[ d ]imidazole by ionic liquid supported eco-friendly green protocol. The precursor, 2-(diethoxymethyl)-1H-benzo[ d ]imidazole was prepared from o -phenylenediamine in good yield. The compound 5 was characterized by 1H, 13C and mass spectroscopic analyses. Also, its structure was further confirmed by X-ray single crystal analysis. From Hirshfeld calculations, it was clear that the H...H (51.1 %), H...C (21.6 %), O...H (18.9 %) and N...H (6.3 %) interactions were the most dominant in the solid-state structure of compound 5. The crystal stability was controlled by the short distance of O3...H7 (2.556 Å), N2...H6 (2.555 Å) and H11C...H11C (1.964 Å). Natural bond orbital (NBO) calculations were used to calculate the different intramolecular charge transfer interactions in the synthesized benzimidazole molecule 5. In addition, the DFT calculations were used to predict its electronic and reactivity descriptors. Furthermore, the synthesized compound was examined for its antioxidant properties and it was found that the compound 5 exhibited potent antioxidant activity (IC 50 value of 42.32 µM) when compared to the standard drug butylated hydroxyanisole (BHA) (IC 50 value of 58.6 µM). In addition, the compound 5 showed significant tuberculosis activity (3.12 µg/mL) against Mycobacterium tuberculosis H37Rv when compared to the standard drug, ethambutol (1.56 µg/mL). The docking simulation was also performed for compound 5 which correlated well with the in vitro findings. [ABSTRACT FROM AUTHOR]

• Synthesis of new class of dispiropyrrolidine grafted indole heterocycle. • Compound was achieved in excellent yield employing cycloaddition strategy. • Compound unambiguously assigned by spectroscopic and XRD analysis. • Structural determination of the compound was explored by theoretical study. • Compound displayed potent antibacterial and antioxidant activities. Synthesis of dispirooxindolopyrrolidine embedded indole hybrid heterocycle was achieved in excellent yield employing intermolecular 1,3-dipolar cycloaddition cascade reaction sequence. The non-stabilized 1,3-dipole component was derived from isatin and l -tryptophan under decarboxylative condensation methodology, was reacts with 3-(4-fluorobenzylidene)indolin-2-one to form 5-benzyl-spiro[2.3′]oxindolo-spiro[3.3′′]-oxindolo-4-[4-fluorophenyl-pyrrolidinewith four stereogenic center via two C C and one C N bonds in single synthetic operation. The structure of compound was undoubtably determined by 1D and 2D NMR spectroscopic analysis. The stereo and regiochemistry of cycloadduct was confirmed through single crystal X-ray diffraction studies. The packing aspects of compound 4 were analyzed using Hirshfeld calculations. It is found that the O...H, N...H, C...H and H...H interactions have major role in the crystal stability. Their percentages are estimated to be 10.1, 3.4, 25.0 and 51.0%, respectively indicating that the H...H contacts are the most dominant. Different electronic parameters such as charge population, dipole moment, molecular electrostatic potential map and frontier molecular orbitals as well as their derived reactivity descriptors were presented. Compound 4 showed potent antibacterial efficacy against E. coli with MIC value of >7.8 µg/mL, besides, compound 4 displayed significant antioxidant activity (84.05%) at the concentration of 500 µg/mL. [ABSTRACT FROM AUTHOR]

• Synthesis of dispiropyrrolidine embedded with indenoquinoxaline and chromanone heterocycles. • Compound was achieved in excellent yield using ionic liquid assisted eco-friendly green protocol. • Structural characterization was done by NMR and single crystal X-ray diffraction analysis. • Compound displayed significant antimicrobial activity against tested microbial pathogens. A regio- and stereoselective synthesis of hitherto unexplored novel class of dispiropyrrolidine embedded with indenoquinoxaline and chromanone hybrid heterocycle has been achieved employing an eco-friendly ionic liquid assisted multicomponent 1,3-dipolar cycloaddition cascade protocol. The dipolarophile, 3-(4-methoxybenzylidene)chroman-4-one reacts with non-stabilized 1,3-dipole component derived from indenoquinoxalinone and l -phenylalanine through decarboxylative cascade reaction pathway affording (2′S,4′S)-5′-benzyl-4′-(4-methoxyphenyl)dispiro[chromane-3,3′-pyrrolidine-2′,11′'-indeno[1,2- b ]quinoxalin]-4-one (6) as the final product. The structure of 6 was confirmed through NMR and mass spectroscopic analyses. Further, stereochemistry of the spirocompound was undoubtedly determined through single crystal XRD analysis. In the crystal structure, the O...H and N...H interactions are the most common contacts and also have great importance in molecular packing. In addition, the C...H contacts are also important in the studied crystal structure. DFT and NBO calculations were performed on this system in order to discuss its electronic and reactivity parameters. The calculated dipole moment value is 2.9238 Debye indicating a polar compound. Compound 6 was assayed for antimicrobial efficacy and found to have potential activity against eight tested microbial pathogens. Among them, E. coli ML_KSUB22 and C. albicans ML_KSUF05 were found to be highly susceptible than the other pathogens. [ABSTRACT FROM AUTHOR]

Antifungal activity of spirooxindolo-pyrrolidine tethered indole and imidazole heterocyclic hybrid, 9c. Invasive fungal infections are one of the leading causes of nosocomial bloodstream infections with a limited treatment option. A series of derivatized spirooxindolo-pyrrolidine tethered indole and imidazole heterocyclic hybrids have been synthesized, and their antifungal activity against fungal strains were determined. Here we characterize the antifungal activity of a specific spirooxindolo-pyrrolidine hybrid, dubbed compound 9c , a spirooxindolo-pyrrolidine tethered imidazole synthesized with a 2-chloro and trifluoromethoxy substituent. The compound 9c exhibited no cytotoxicity against mammalian cell line at concentrations that inhibited fungal strains. Compound 9c also significantly inhibited the fungal hyphae and biofilm formation. Our results indicate that spirooxindolo-pyrrolidine heterocyclic hybrids potentially represent a broad class of chemical agents with promising antifungal potential. [ABSTRACT FROM AUTHOR]

A new class of (N‐(pyrimidin‐2‐yl)‐4‐((1,7,7‐trimethylbicyclo [2.2.1] heptan‐2‐ylidene) amino) benzenesulfonamide (CDA) was synthesized from commercially available camphor and sulfadiazine. The synthesized Schiff‐base was characterized by FT‐IR, 1H and 13C NMR spectroscopic analyses. The HOMO, LUMO, MEP, chemical reactivity parameters, and NBO were calculated using the WB97XD/cc‐pVDZ basis set. For better understanding, the electronic absorption and emission of the compound were recorded using UV‐Vis and fluorescence spectra. Molecular docking simulations were investigated between ligand (compound) and target protein. The computational results correlate well with observed values. The frontier molecular orbital energy gap (3.78 eV) revealed that the studied molecule has higher polarizability and chemical reactivity with lower kinetic stability. In addition, compound showed the highest binding score −5.72 kcal/mol, which was confirmed by a molecular docking simulation. [ABSTRACT FROM AUTHOR]

• Spiropyrrolidine embedded chromanones were achieved in excellent yield. • Spiropyrrolidines were synthesized using one-pot cycloaddition methodology. • Compounds unambiguously assigned by spectroscopic and single crystal XRD analysis. • Structural determination of the compounds was investigated by computational study. Synthesis of a new class of heterocyclic hybrid embedding spirooxindole, pyrrolidine and chromanone structural moieties was achieved in excellent yield using an intermolecular [3+2]-cycloaddition cascade reaction protocol. The synthesized spiropyrrolidines were unambiguously determined by spectroscopic analysis and the stereo- and regiochemistry of the cycloadducts were undoubtably assigned by single crystal X-ray diffraction analysis. Structural features of the compounds were examined by using X-ray crystallographic studies. The molecular packing was defined by Hirshfeld surface analysis. Furthermore, the structure and reactivity of the synthesized dispiropyrrolidines were investigated by density functional theory (DFT) calculations. [ABSTRACT FROM AUTHOR]

A small library of new class of dispiropyrrolidinyl-piperidone tethered indono[1,2- b ]quinoxaline heterocyclic hybrids 7 a – j were synthesized employing multicomponent 1,3-dipolar cycloaddition strategy in [bmim]Br. The azomethine ylide employed is first of its kind and generated in situ from indenoquinoxalinone and l -tryptophan, a combination that has not been employed previously for the in situ generation of azomethine ylides. The synthesized heterocyclic hybrids 7a – j were evaluated for their in vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities, therein compounds 7h and 7j displayed more potent AChE and BChE enzyme inhibition than the standard drug with IC 50 values of 3.22, 2.01, 12.40 and 10.45 mM, respectively. Molecular docking studies have also been investigated for most active compounds that disclosed interesting binding templates to the active site channel of cholinesterase enzyme. [ABSTRACT FROM AUTHOR]

Graphical abstract Antifungal activities of benzimidazole tethered pyrrolo[3,4- b ]quinoline compounds. Abstract Fungal infections caused by Candida and Cryptococcus are particularly dangerous for immunocompromised individuals. In this study, we identified that benzimidazole fused pyrrolo[3,4- b ]quinoline compounds have potent antifungal activity against several clinical isolates of pathogenic fungal strains. Specifically, the compound 6a did not show cytotoxicity against mammalian cells at a concentration that inhibits the growth of fungal strains. In addition, the compound 6a also significantly reduced the metabolic activity of fungal cells in the Candida albicans biofilms. Collectively, our results indicate that benzimidazole fused quinoline compounds have a potential to develop as an antifungal agents. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A series of structurally intriguing pyrrolo[3,2- c ]quinolinones were synthesized in excellent yields. • These heterocyclic hybrids were achieved employing multicomponent domino protocol. • The reaction provided five new bonds, three new rings and four contiguous stereocenters. Abstract A series of structurally intriguing novel pyrrolo[3,2- c ]quinolinone heterocyclic hybrids have been synthesized for the first time via a one-pot multicomponent domino reaction sequence that involves a 1,3-dipolar cycloaddition and two subsequent annulation steps. Baylis-Hillman adducts derived from various substituted benzaldehyde and methyl acrylate in presence of DABCO were used as a dipolarophiles, while the 1,3-dipole components were azomethine ylides, formed in situ from isatin derivatives and l -phenylalanine. The reaction generated five new bonds, three new rings and four contiguous stereocenters, which were created with full diastereomeric control. [ABSTRACT FROM AUTHOR]

A new type of optically pure primary amino aromatic Tf-amide organocatalyst can be easily prepared from 8-amino-1-tetralone, and its chemical behavior was investigated in the context of asymmetric aldol and Mannich reactions. Most notably, the asymmetric aldol reaction proceeded smoothly in brine. [ABSTRACT FROM AUTHOR]

Abstract A new and convenient approach has been deviced for the practical synthesis of structurally robust, four different pseudoenantiomeric amino Tf-amido organocatalysts with the unique cis - and trans -substituted 1,2-cis-cyclohexanediamine structures. These pseudoenantiomeric organocatalysts are easily prepared by the Diels-Alder strategy of 2-phenyl-1,3-butadiene and maleic anhydride, and their chemical behavior was investigated by their application to asymmetric aldol synthesis for the practical synthesis of both enantiomeric aldols. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

Abstract A small library of novel hybrid spiroheterocycles containing spirooxindole, pyrrolidine and indole/imidazole moieties were synthesized with complete regio- and diastereoselectively in good to excellent yields from a three-component process starting from a series of variously substituted ( E )-(2-nitrovinyl)benzenes, indoline-2,3-dione derivatives and l -tryptophan or l -histidine in an ionic liquid. The key step of this transformation is a 1,3-dipolar cycloaddition reaction involving a rare class of in situ -generated azomethine ylides derived from aromatic amino acids. The compounds thus synthesized were evaluated for their anticancer activity and were shown to inhibit the proliferation of FaDu cells, a human epithelial cell line isolated from a squamous cell carcinoma of the hypopharynx, via apoptotic cell death. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

A regio and stereo- selective synthesis of hitherto unexplored hybrid heterocyclic system comprising spiropyrrolidine, indolizino[6,7- b ]indole units in good to excellent yields, has been developed via three component 1,3-dipolar cycloaddition and concomitant trifluoroacetic acid catalyzed Pictet-Spengler cyclization with paraformaldehyde. The newly synthesized compounds were evaluated for their in vitro acetylcholinesterase (AChE) and butylcholinesterase (BChE) enzyme inhibitory activities. Most of the synthesized compounds showed good inhibitory activity, among them, compounds 4d and 4g displayed highest potency against AChE (IC 50 1.88 and 1.98 μM), and BChE (IC 50 18.32 and 10.21 μM) enzyme, respectively than the standard drug, galanthamine. Molecular modeling simulation was investigated for the most active compounds 4d and 4g on AChE and BChE enzymes to disclose the binding and orientation of these molecules into active site of respective receptors. [ABSTRACT FROM AUTHOR]

In this account, we describe our recent developments in organocatalyzed asymmetric methodologies for the practical synthesis of both enantiomers. The synthesis of both enantiomeric products by using both enantiomeric catalysts is the most traditional way. In addition, use of two pseudoenantiomeric catalysts provides a more practical approach for the synthesis of both enantiomeric products. Even more efficient is the use of a single enantiomeric catalyst in the presence or absence of certain additives for obtaining both enantiomeric products. These three different strategies are illustrated by using certain organocatalyzed asymmetric approaches. [ABSTRACT FROM AUTHOR]

A small library of benzimidazole-fused pyrrolo[3,4- b ]quinoline has been synthesized from readily available benzimidazole 2-carbaldehyde and various substituted arylamines in good to excellent yields utilizing an intramolecular Povarov reaction catalyzed by boron trifluoride diethyl etharate as the key final step. The compounds thus synthesized can be considered as decarbonyl analogues of the anticancer alkaloid luotonin A and were evaluated in a DNA relaxation assay for their ability to inhibit human topoisomerase I. Interestingly, two of the compounds showed a remarkable activity that is comparable to that of the standard drug camptothecin. The compounds were also evaluated for their cytotoxic effect in four highly aggressive human cancer cell lines, namely KB, MDA-MB231 (breast), LNCap (prostate), and HT1080 (fibrosarcoma). Some of the compounds obtained showed promising cytotoxicities for these four cell lines. [ABSTRACT FROM AUTHOR]

Transition metal oxide based materials are believed as a sustainable and effective electrocatalysts for oxygen evolution and oxygen reduction reactions (OER/ORR). However, poor conductivity, specific surface area, and tunable crystallography are major bottlenecks. To alleviate such issues, we developed a highly active spinel Co 3 O 4 decorated N-doped hollow carbon sphere (Co 3 O 4 /NHCS) by single step decoration using cobalt phthalocyanine (CoPc) precursor for the first time. The introduction of various extents of CoPc significantly affects the sphere wall thickness, defect sites, doping amount of cobalt content, and the concentration of Co3+ and Co2+ sites. The resulting optimum loading of 0.2 g of Co 3 O 4 /NHCS-0.2, exhibits a highly uniform hollow carbon sphere with a high wall thickness (61 nm), better surface area (445 m2 g−1), and moderate defect sites. Notably, an exterior concentration of octahedral Co3+ (35.50%) and tetrahedral Co2+ (26.54%) sites serve as the active centres for OER and ORR, respectively. Remarkably, the obtained material exhibits exceptional OER performance with a potential of 1.80 V vs. RHE in 0.1 M KOH medium for achieving a current density of 10 mA cm−2, outperforming the benchmark RuO 2 material. In addition, Co 3 O 4 /NHCS-0.2 demonstrates an impressive ORR electrocatalytic activity with onset potential of 0.89 V vs. RHE, excellent current density of 5.0 mA cm−2, lower Tafel slope of 60 mV dec−1 and close to four electron transfer. Moreover, the moderate carrier concentration, flat band potential, higher tetrahedral Co2+ and pyridinic N sites significantly improved the ORR activity and methanol oxidation tolerance ability. [Display omitted] • Co 3 O 4 decorated N-doped hollow carbon sphere by single step process. • The 0.2 g of cobalt phthalocyanine shows the higher Co3+/Co2+ ratio. • Co 3 O 4 /NHCS-0.2 possesses a remarkable OER activity. • Co 3 O 4 /NHCS-0.2 demonstrates an impressive ORR activity. [ABSTRACT FROM AUTHOR]

Abstract B3LYP/cc-pVDZ generated the best N-(5-((4-ethylpiperazin-1-yl)methyl)pyridin-2-yl)-5-fluoro-4-(4-fluoro-1-isopropyl-2-methyl-1H-benzo[d] imidazol-6-yl) pyrimidin-2-amine (TA) results. The NBO study shows that the LP (1) N16 to π*(C17-N19) has the highest stabilization energy at 53.86 kcal/mol. Electron localization and delocalization areas are confirmed by wavefunction studies. The Gaussian-16w software establishes thermodynamic properties for a titled compound which is confirmed by various solvents. The frontier molecular orbital studies we confirmed by gas phase have the highest bond gap value which is 4.02 eV. The titled compound nitrogen is the nucleophilic attack (blue color) and oxygen is the electrophilic attack (red color), which is confirmed by MEP study. In non-linear optical (NLO) study water solvent shows the highest dipole moment activity, due to the solvent’s interaction the gas phase dipole moment is lower. The docking study showed the greatest binding affinity score of −5.28 kcal/mol. [ABSTRACT FROM AUTHOR]

An Ru(II)‐catalyzed C−H annulations of oximes and N‐methoxybenzamides with bridged alkyne is described. This method is useful for the efficient synthesis of various macrocyclic isoquinolines and isoquinolones in good to moderate yields. A possible mechanism, involving a key five‐membered metallacycle intermediate, alkyne insertion followed by reductive elimination to give a final annulated product has been proposed. [ABSTRACT FROM AUTHOR]

A stereo‐, regio‐ and chemoselective synthesis of a series of structurally diverse novel oxobenzothiophene embedded spirooxindolopyrrolidine/pyrrolizidine hybrid heterocycles were achieved in excellent yields by multicomponent 1,3‐dipolar cycloaddition reaction process. The 1,3‐dipole component employed was generated in situ from isatin and N‐methylglycine/L‐proline while the dipolarophile, ethyl 2‐(3‐oxobenzo[b]thiophen‐2(3H)‐ylidene)acetate was prepared from thiophenol in two good yielding steps. The formation of spiroheterocyclic hybrids occurred through the formation of two C=C and one C−N bonds in a single synthetic transformation. The compounds formed consists of three adjacent stereocenters, out of which two are spirocarbons. The synthesized spiro compounds were assayed for their AChE/BChE inhibitory activity and most of the spirocompounds showed promising cholinesterase inhibitory activity. Among them, spiropyrrolidine that substituted with chlorine atom on the oxindole ring displayed significant activity (4.16±0.09 μM) with respect to standard drug, galantamine (2.09±0.11 μM). Molecular modelling simulation was explored for the most potent compound that revealed interesting binding templates to the active site of enzyme. [ABSTRACT FROM AUTHOR]

A novel efficient eco-friendly on “ionic liquid” method has been developed for the synthesis of multi-functionalized isoxazolidines through a nitrone 1,3-dipolar cycloaddition reaction. The low cost and eco-benign room temperature ionic liquid, acetylcholine iodide-ethylene glycol (ACI/EG) accelerates the formation of the desired regioselective mono-/di isoxazolidine analogues and reduced the reaction time with high level of chemical yield. Furthermore, the recyclability of ACI/EG has also been investigated. [ABSTRACT FROM AUTHOR]

• Dispiropyrrolidines synthesized in excellent yield via cycloaddition strategy. • Compounds were elucidated by spectroscopic and single crystal X-ray analysis. • Molecular packing and structure reactivity descriptors were investigated. • Compounds assayed for their antimicrobial activity against K. pneumonia strains. • Antimicrobial efficacy was also performed through molecular docking study. A regio and stereoselective synthesis of a new class of spirooxindolopyrrolidine embedded indandione heterocycles was obtained in excellent yield employing a three-component cascade reaction protocol. The key step for this protocol is a 1,3-dipolar cycloaddition reaction involving azomethine ylide generated in situ from isatin and l -phenylalanine. The structure of newly synthesized compound was assigned based on the NMR spectroscopic analysis and the stereo/regiochemistry was undoubtable assigned by single crystal X-ray diffraction analysis. Further, the structural determination of the compound was assigned through density functional theory (DFT) and Hirshfeld surface analysis. It is found that the compound was highly stabilized by intermolecular interactions such as X-H-H-X (X = C and O) and also by hydrogen bonding interaction. The synthesized compounds were assayed for their antibacterial activity against five different clinical bacterial strains of K. pneumoniae and found that the compound possessing chloro‑substitution on aryl ring showed significant activity against tested K. pneumoniae strains. [Display omitted] [ABSTRACT FROM AUTHOR]

series of benzimidazole-tethered oxazepine heterocyclic hybrids has been synthesized in good to excellent yields from an N-alkylated benzimidazole 2-carboxaldehyde, which in turn was accomplished from o-phenylenediamine in three good yielding steps. The calculated molecular structure of compounds 2-methyl-4-(2-((phenylimino)methyl)-1H-benzo-[d]imidazol-1-yl)-butan-2-ol 9 and 10 3,3-dimethyl-N-phenyl-1,2,3,5-tetrahydrobenzo-[4,5]imidazo[2,1-c][1,4]oxazepin-5-amine using the B3LYP/6-31 G(d, p) method were found to agree well with their X-ray structures. The charge distributions at the different atomic sites were computed using the natural bond orbital (NBO) method. The regions of electrophilic and nucleophilic reactivity were shown using a molecular electrostatic potential (MEP) map. In addition, the frontier molecular orbitals of these compounds were discussed at the same level of theory. Nonlinear optical (NLO) properties have also been investigated by computational hyperpolarizability studies, and it was found that Compound 9 is the best candidate for NLO applications. [ABSTRACT FROM AUTHOR]

A series of novel pyrrolo[3,4- b ]quinolines have been synthesized from N -alkynyl aldehydes and various substituted arylamines in good to excellent yields utilizing an intramolecular Povarov reaction catalyzed by boron trifluoride diethyl etherate as the key final step. [ABSTRACT FROM AUTHOR]

A series of hitherto unreported anthracene-embedded dispirooxindoles has been synthesized via a one-pot three-component 1,3-dipolar cycloaddition reaction of an azomethine ylide, generated in situ from the reaction of isatin and sarcosine to 10-benzylideneanthracen-9(10H)-one as a dipolarophile in 1-butyl-3-methylimidazolium bromide([bmim]Br), an ionic liquid. This reaction proceeded regio- and diastereoselectively, in good to excellent yields. [ABSTRACT FROM AUTHOR]

A facile synthesis of dispirooxindolopyrrolidines has been accomplished via a one-pot three component 1,3-dipolar cycloaddition reaction. The reaction of azomethine ylides generated in situ from L-phenylalanine and substituted isatins with a series of unusual (E)-2-oxoindolino-3-ylidene acetophenone dipolarophiles in the ionic liquid 1-butyl-3-methylimidazolium bromide [bmim]BF4, furnished the cycloadducts in good yields, with the regioisomers 5a-f being obtained with high selectivity. Furthermore, the recyclability of [bmim]BF4, up to five times, was also investigated. [ABSTRACT FROM AUTHOR]

• Synthesis of a structurally unexplored novel class of ferrocene fused spiropyrrolidine hybrid. • Spiro compound was achieved in excellent yield via a one-pot multicomponent cascade protocol. • The synthesized compound was elucidated by spectroscopic, X-ray diffraction and computational studies. • Spirocompound displayed significant activity against tested MDR S. aureus strains. Our synthetic approach for the assembly of highly diversified spiropyrrolidine grafted ferrocene was based on a one-pot four component cascade reaction protocol involving 1,3-dipolar cycloaddition reaction of (E)-3-ferrocene-1-(4-bromophenyl)prop‑2-en-1-one and azomethine ylide generated in situ from quinoxalinone and l -tryptophan. The structure of the compound was assigned by one- and two-dimensional NMR spectroscopic studies. The regio- and stereochemistry of the spirocompound was confirmed by single crystal X-ray diffraction analysis. The nature of three-dimensional orientation of the synthesized compound has been investigated through single crystal X-ray diffraction study. Crystal structure of the synthesized compound was analyzed using Hirshfeld calculations. In spirocompound, the packing of molecules is controlled by significant O...H (3.3%), N...H (4.1%) and C H...π (24.8%) interactions. The different π-donation and π-back donation interactions was analysed using NBO calculations. The compound 6 exhibited potent inhibitory activity against tested MDR S. aureus strains ranging from 8.00 to 256.00 µg/mL with respect to MIC and MBC determination. [ABSTRACT FROM AUTHOR]

• Structurally diverse azetidinone integrated spirooxindolopyrrolidine has been accomplished. • Spirocompound has been synthesized through green synthetic protocol using ionic liquids. • Structure of spirocompound elucidated through spectroscopic, X-ray and DFT studies. • Antibacterial potential of the synsthesized compound has also been investigated. Synthesis of structurally diverse novel class of azetidinone integrated spirooxindolopyrrolidine heterocyclic hybrid was achieved in excellent yield employing a single-pot intermolecular 1,3-dipolar cycloaddition cascade protocol. The highly functionalized dipolarophile, azetidinone Baylis-Hillman adduct, was prepared from 4-formyl azetidinone whereas the non-stabilized 1,3-dipole component was derived from trifluoromethoxyisatin and l -phenylalanine via decarboxylative condensation. The structure of the product was determined by X-ray diffraction on single crystal method. Further, the crystal structure was analyzed using Hirshfeld calculations. The packing of molecules is controlled by the O...H (19.2%), F...H (17.3%), C...C (3.2%) and N...H (14.8%) which are the most significant in cycloadduct. The electronic and reactivity descriptors of the cycloadduct were calculated on the basis of DFT calculations. The synthesized heterocyclic hybrid displayed significant activity against selected ESBL producing E. coli strains and the minimal MIC values was observed against E. coli WTP005. [Display omitted] [ABSTRACT FROM AUTHOR]

Quinoline Schiff bases display potential applications in optoelectronics and laser fields because of their unique optical properties that arise from extensive delocalization of the electron cloud, and a high order of non-linearity. In this context, a new class of conjugated quinoline-derivative viz. N-(quinolin-3-ylmethylene)anilines were synthesized from 2-hydroxyquinoline-3-carbaldehyde in two good yielding steps. The ability of these imines to accept an electron from a donor is denoted by their electron acceptor number and sites, which is calculated using density functional theory (DFT). The optical properties such as FT-IR, Raman, UV-VIS, and EDS spectra were calculated using TD-DFT, which also provided the energy gap, HOMO-LUMO structure. The optical properties of the synthesized imino quinolines were experimentally studied using photoluminescence and absorption spectroscopy. The properties such as Stokes shift and quantum yield were calculated using experimental data. Furthermore, the compound bearing a methyl group on the aryl ring and ZnO nanoparticles (hydrothermally synthesized) were dissolved in toluene, and optically excited with a 355 nm nanosecond laser, which produced a random laser. [ABSTRACT FROM AUTHOR]

Highlights: [•] Synthesis of hitherto unreported morpholine fused unusual spiroheterocyle. [•] Product achieved in good yield via one-pot cascade reaction sequence. [•] The structure determined by spectral and single crystal X-ray diffraction studies. [•] Formation of spiroheterocyle has been investigated through DFT calculation. [ABSTRACT FROM AUTHOR]

Abstract: An expedient regio-, stereo- and product-selective synthesis of novel hybrid heterocyclic systems comprising [1,2-c]oxazolidine, pyrrolidine and piperidine units, in good to excellent yields, has been developed via three-component 1,3-dipolar cycloaddition/annulation domino reactions and concomitant trifluoroacetic acid mediated condensative annulation with paraformaldehyde. These novel structurally complex heterocyclic hybrids, accessed by a two-step protocol, possess seven rings and seven contiguous stereocentres. [Copyright &y& Elsevier]

A series of novel 1-(2′-α-O-D-glucopyranosyl ethyl) 2-arylbenzimidazoles has been prepared via one-pot glycosylation of ethyl-1-(2'-hydroxyethyl)-2-arylbenzimidazole-5-carboxylate derivatives. Synthesis of the 2-arylbenzimidazole aglycones from 4-fluoro-3- nitrobenzoic acid was accomplished in four high-yielding steps. The reduction and cyclocondensation steps for the aglycone synthesis proceeded efficiently under microwave irradiation to afford the appropriate benzimidazoles in excellent yields within 2-3 min. Glycosylation of the hydroxyethyl aglycones with the perbenzylated 1-hydroxyglucopyranose, pretreated with the Appel-Lee reagent, followed by catalytic hydrogenolysis delivered the desired 1-(2′-α-O-D-glucopyranosyl ethyl) 2-aryl-benzimidazoles in a simple and straightforward manner. [ABSTRACT FROM AUTHOR]

Abstract: A facile and efficient synthesis of novel chromeno[4,3-b]pyrroles has been accomplished by intramolecular 1,3-dipolar cycloaddition which on subsequent Pictet–Spengler cyclisation in presence of p-toluenesulfonic acid yielded indolizino[6,7-b]indoles. The synthesized chromenopyrroles and indolizinoindoles were evaluated for their antimicrobial and antioxidant activities. Compounds 7b, 7e, 7a and 7d exhibited respectively, good antibacterial and antifungal activities against tested pathogens when compared to reference control. [Copyright &y& Elsevier]

[image omitted] One-pot synthesis of novel β-lactam-grafted spiropyrrolidines has been accomplished in good yield via a facile [3 + 2] cycloaddition reaction of azomethine ylides, derived from β-lactam aldehyde and sarcosine, with various p-substituted (E)-2-oxoindoline-3-ylidene acetophenone derivatives as dipolarophiles. The reaction gave excellent yields of the products when carried out under microwave irradiation. [ABSTRACT FROM AUTHOR]

Abstract: A facile and one-pot synthesis of a series of novel spiropyrrolidines/pyrrolizidines with β-lactam substituent has been accomplished through 1,3-dipolar cycloaddition reaction of alkenyl esters derived from β-lactam aldehyde as dipolarophile with the dipole azomethine ylide derived from 1,2- and 1,3-diketones and secondary amino acids. The synthesized compounds were evaluated for antimicrobial activities and found to exhibit relatively good antibacterial activity at lower concentration against four human bacterial pathogens. [ABSTRACT FROM AUTHOR]

Abstract: Synthesis of novel β-lactam fused spiroisoxazolidine chromanones and tetralones ring systems has been achieved by intermolecular 1,3-dipolar cycloaddition reaction of bicyclic nitrone with unusual dipolarophiles, arylidene chromanones/tetralones under different reaction conditions. The synthesized compounds were evaluated for antimicrobial activities. It was observed that two of the synthesized compounds exhibited relatively good antibacterial and antifungal activities. [Copyright &y& Elsevier]

Abstract: Synthesis of novel pyrroloisoquinoline and indolizinoindole derivatives with β-lactam unit has been achieved by sequential intermolecular 1,3-dipolar cycloaddition reaction and Pictet-Spengler cyclization. The azomethine ylide derived from β-lactam imine of α-amino ester in the presence of silver acetate reacted with nitrostyrenes to give pyrrolidinyl β-lactam, which underwent Pictet-Spengler cyclization in presence of trifluoroacetic acid to give pyrroloisoquinolines and indolizinoindoles. [Copyright &y& Elsevier]

• Structurally diverse spirooxindole-pyrrolidine molecular scaffolds achieved. • Their molecular structures were elucidated from NMR, X-ray and DFT studies. • Hirshfeld analysis was performed to determine different intermolecular contacts. • DFT computed parameters are in good agreement with experimental findings. Structurally diverse highly functionalized flouro- and nitro - substituted spirooxindole-pyrrolidine heterocyclic hybrids have been achieved in good yields. The molecular structure of these diverse spiroheterocyclic hybrids was elucidated by spectroscopic analysis and further confirmed by single crystal X-ray crystallographic studies and density functional theory (DFT) calculations. Analysis of molecular packing for these hybrids was performed using Hirshfeld analysis. Geometric parameters calculated by DFT are in good agreement with the experimental data obtained from X-ray crystallography. Structurally diverse highly functionalized flouro- and nitro - substituted spirooxindole-pyrrolidine molecular scaffolds have been achieved and their molecular structures were elucidated by NMR spectroscopy and X-ray crystallographic studies. Geometric parameters calculated by DFT are in good agreement with the experimental data obtained from the X-ray crystallography. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: A highly regio- and stereoselective synthesis of novel spiro pyrrolidines/pyrrolizidines containing β-lactam and oxazolone moieties under two different conditions is achieved using [3+2] cycloaddition methodology in moderate to good yield. [Copyright &y& Elsevier]

[Display omitted] • Novel spirooxindolopyrrolidine tethered indandiones have been synthesized in excellent yields. • A one-pot eco-friendly three component cycloaddition strategy have been employed. • Compounds were assessed for their antimycobacterium activity against Mtb H37Rv. • Compound with chloro substituent displayed two fold activity than that of standard drug, ethambutol. Novel spirooxindolopyrrolidine embedded indandione heterocyclic hybrids were obtained in excellent yields via a regio- and stereoselective one-pot three component reaction between Baylis-Hillman adduct and non-stabilized azomethine ylides. The structure of newly synthesized compounds was elucidated through 1D and 2D spectroscopic data and the stereochemistry was determined by single crystal X-ray diffraction analysis. In vitro tubercular activity against Mycobacterium tuberculosis H37Rv using MABA assay reveals that the compound bearing chlorine substituted on the oxindole ring displayed the most potent activity with MIC 0.78 μg/mL and is two-fold active than the standard drug, ethambutol (MIC 1.56 μg/mL). [ABSTRACT FROM AUTHOR]

The aqueous extract of Alternanthera sessilis (As) acts as the precursors for the quick reduction of silver ions, which leads to the formation of silver nanoparticles. In the agar, well diffusion method of the Klebsiella pneumoniae shows the minimal inhibitory concentration of 12 mm against A. sessilis mediated silver nanoparticles (As-AgNPs) at 60 µg/mL concentration. Fabric treated with novel AS-AgNPs is tested against the K. pneumoniae and shows an inhibitory action of 12 mm with mixed cotton that determines the antimicrobial efficacy of the fabrics. Uv- visible spectrophotometer was performed, showing a surface plasmon resonance peak at 450 nm cm−1. FTIR shows the vibration and the infrared radiation at a specific wavelength of 500–4000 cm−1. The HR-TEM analysis showed the presence of black-white crystalline, spherical-shaped As-AgNPs embedded on the fabrics range of 15 nm–40 nm. In the scanning electron microscope, the presence of small ball-shaped As-AgNPs embedded on the fabrics at a voltage of 30 KV was found with a magnification of 578X. EDAX was performed in which the nanoparticles show a peak of 2.6–3.9 KeV, and it also reveals the presence of the composition, distribution, and elemental mapping of the nanoparticles. The cytotoxic activity of synthesized nanosilver was carried out against L929 cell lines, which show cell viability at a concentration of 2.5 µg mL−1. Cell proliferation assay shows no cytotoxicity against L929 cell lines for 24 h. In this study, the green synthesis of silver nanoparticles from A. sessilis appears to be a cheap, eco-friendly, and alternative approach for curing infectious ulcers on the floor of the stratum corneum. Nanotechnology conjoined with herbal therapeutics provides a promising solution for wound management. [ABSTRACT FROM AUTHOR]

The contemporary food industry's uses of nanoemulsions (NEs) include food processing, effective nutraceutical delivery, the development of functional chemicals, and the synthesis of natural preservatives, such as phytocompounds. Although cinnamon essential oil (CEO) is widely used in the cosmetic, pharmaceutical, and food industries, it is difficult to add to aqueous‐based food formulations due to its weak stability and poor water solubility. This study describes the formulation of a CEO nanoemulsion (CEONE) by spontaneous emulsification and evaluates its antibacterial and antibiofilm properties against biofilm‐forming Serratia rubidaea BFMO8 isolated from spoiled emperor fish (Lethrinus miniatus). Bacteria causing spoilage in emperor fish were isolated and identified as S. rubidaea using common morphological, cultural, and 16S RNA sequencing methods, and their ability to form biofilms and their susceptibility to CEONE were assessed using biofilm‐specific methods. The spontaneous emulsification formulation of CEONE was accomplished using water and Tween 20 surfactant by manipulating organic and aqueous phase interface properties and controlling particle growth by capping surfactant increases. The best emulsification, with highly stable nano‐size droplets, was accomplished at 750 rpm and a 1:3 ratio concentration. The stable CEONE droplet size, polydispersity index, and zeta potential values were 204.8 nm, 0.115, and −6.05 mV, respectively. FTIR and high‐resolution liquid chromatography‐mass spectrometry (HR‐LCMS) analyses have revealed carboxyl, carbonyl, and phenol‐like primary phytochemical functional groups in CEO and CEONE, which contribute to their antibacterial and antibiofilm properties. [ABSTRACT FROM AUTHOR]

• Structurally intriguing novel spiroheterocyclic hybrid has been synthesized in excellent yield. • Spiroheterocycle has been achieved via one-pot [bmim]Br accelerated multicomponent green protocol. • The structure and stereochemistry of the compound elucidated by spectroscopic and X-ray analysis. • Molecular packing and interaction has been investigated by Hirshfeld and DFT calculations. • Food borne bacterial inhibitory activity observed. Synthesis of a hybrid heterocycle comprising ferrocene, spiropyrrolidine and quinoxaline structural moieties have been achieved in good yield via ionic liquid expedited multicomponent 1,3-dipolar cycloaddition reaction. Structural properties of the synthesized compound were exploited using single crystal X-ray crystallographic studies. Hirshfeld analysis revealed the importance of H...H (59.6%), C H...π (22.4%) and N...H (3.5%) contacts within the molecular packing. The Fe-C interactions around ferrocenyl moiety were investigated using Natural Bond Orbital (NBO) and Atoms In Molecules (AIM) calculations. A predominant covalent character of interactions between Fe-C were been accessed from AIM calculation. A weaker extend of π-back donation appeared in cyclopentadienyl moiety carrying the substituent instead of unsubstituted one. Further, the in vitro antimicrobial potential of the synthesized compound against five food borne bacterial pathogens reveals its significant activity against E. coli and S. enterica with MIC values 6.00 µg/mL and 8.00 µg/mL, respectively. The antioxidant activity of compound 5 was found to be 84.37±0.55 at 250 µg/mL concentration with an IC 50 value = 33.80 µg/mL. [ABSTRACT FROM AUTHOR]

• A novel spiropyrrolidine heterocyclic hybrid was achieved in good yield. • Structural aspects were done using spectroscopic and X-ray diffraction analysis. • Regioselectivity and possible transition states were investigated by DFT studies. • AChE and BChE inhibitory activity observed. A facile eco-friendly approach for the regio- and stereoselective synthesis of structurally intriguing novel spiropyrrolidinoquinoxaline tethered indole hybrid heterocycle has been accomplished via a cascade reaction sequence involving 1,3-dipolar cycloaddition as the key step. Structural elucidation of the synthesized spiroheterocycle was performed by NMR spectroscopy, mass spectrometric analysis and the stereochemistry of asymmetric carbons have been confirmed by single crystal X-ray diffraction analysis. The mechanistic rationalization for the formation of spiroheterocyclic hybrid was investigated through density functional theory (DFT) calculations. In addition, the synthesized spiroheterocyclic hybrid was tested for its cholinesterase inhibitory activity against ChEs and displayed good activity when compared to the standard drug galantamine. [ABSTRACT FROM AUTHOR]