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A high efficiency protocol was developed for the synthesis of 2,5-disubstituted oxazoles via iodine-promoted oxidative domino cyclization. These reactions were performed with readily available methyl azaarenes and α-amino ketones under metal-free conditions. This protocol is a simple method with high functional group compatibility, a wide range of substrates, and excellent yield, providing a new way to synthesize azaarene-attached oxazoles.

Self-assembly of nanomaterials, directed by molecular or supramolecular interactions, is a powerful strategy to build nanoscale devices. Despite many advantages of such solution-based processes, a big challenge is to realize interparticle ohmic contacts toward facilitated charge transport over a long distance. We report a new concept of primed nanowelding to thread solution-borne nanoparticles in prescribed assemblies. The process starts with a gap-specific deposition of Ag

An efficient Pd-catalysed β-C(sp3)–H arylation of diverse native amides with aryl iodides was developed. This protocol overcomes the necessity of the Thorpe–Ingold effect and features broad substrate scope and good functional group tolerance. The potential application of this protocol is collectively demonstrated by gram-scale synthesis and the synthesis of several bioactive molecules.

Herein, we report a novel strategy to access CH2F-containing ketones through Pd-catalysed β-selective methyl C(sp3)-H fluorination. The reaction features high regioselectivity and a broad substrate scope, constituting a modular method for the late-stage transformation of the native methyl (CH3) into the monofluoromethyl (CH2F) group.

A nitrate-promoted Pd-catalysed mild cross-dehydrogenative C(sp2)-H bond oxidation of oximes or azobenzenes with diverse carboxylic acids has been developed. In contrast to the previous catalytic systems, this protocol features mild conditions (close to room temperature for most cases) and a broad substrate scope (up to 64 examples), thus constituting a versatile method to directly prepare diverse O-aryl esters. Moreover, the superiority of the nitrate additive in this mild transformation was further determined by experimental and computational evidence.

The catalytic cracking of low concentration coal tar in syngas was studied using Mg-Ca composite catalyst. The reaction was carried out in a two-stage fixed bed reactor. The effects of bed temperature (400–800 ℃), catalyst particle size (400–600 μm, 200–400 μm, 100–200 μm, and 700 ℃), the catalyst activity for coal tar cracking is reduced.

Selective dehydrogenation of ethanol to acetaldehyde has been considered as an important pathway to produce acetaldehyde due to the atom economy and easy separation of acetaldehyde and hydrogen. Copper catalysts have attracted much attention due to the high activity of Cu species in O-H and C-H bonds oxidative cleavage, and low process cost; however, the size of the Cu nanoparticle is difficult to control since it is easily suffers from metal sintering at high temperatures. In this work, the Cu/KIT-6 catalyst exhibited an ultra-high metal dispersion of 62.3% prepared by an electrostatic adsorption method, due to the advantages of the confinement effect of mesoporous nanostructures and the protective effect of ammonia water on Cu nanoparticles. The existence of an oxidation atmosphere had a significant effect on the valence state of copper species and enhancing moderate acid sites. The catalyst treated by reduction and then oxidation possessed a moderate/weak acid site ratio of ~0.42 and a suitable proportion of Cu+/Cu0 ratio of ~0.53, which conceivably rendered its superior ethanol conversion of 96.8% and full acetaldehyde selectivity at 250 °C. The catalyst also maintained a high selectivity of >99% to acetaldehyde upon time-on-stream of 288 h.

Background: A keloid is a benign skin tumor that extends beyond the initial injury area, and its pathologic mechanism remains unclear. Method: High-throughput sequencing data were obtained from normal skin tissue of patients with keloids (Group N) and healthy controls (Group C). Important genes were mined by bioinformatics analysis and identified by RT–qPCR, Western blotting, immunohistochemistry and immunofluorescence assays. The CIBERSORT algorithm was used to convert gene expression information into immune cell information. Flow cytometry was used to verify the key immune cells. Fluorescence-activated cell sorting coculture and CCK8 experiments were used to explore the effect of CD8+ T cells on keloid-associated fibroblasts. Neural network models were used to construct associations among CD28, CD8+ T cells and the severity of keloids and to identify high-risk values. Result: The expression levels of costimulatory molecules (CD28, CD80, CD86 and CD40L) in the skin tissue of patients with keloids were higher than the levels in healthy people (p < 0.05). The number of CD8+ T cells was significantly higher in Group N than in Group C (p < 0.05). The fluorescence intensities of CD28 and CD8+ T cells in Group N were significantly higher than those in Group C (p = 0.0051). The number and viability of fibroblasts cocultured with CD8+ T cells were significantly reduced compared with those of the control (p < 0.05). The expression of CD28 and CD8+ T cells as the input layer may be predictors of the severity of keloids with mVSS as the output layer. The high-risk early warning indicator for CD28 is 10–34, and the high-risk predictive indicator for CD8+ T cells is 13–28. Conclusions: The abnormal expression of costimulatory molecules may lead to the abnormal activation of CD8+ T cells. CD8+ T cells may drive keloid-associated immunosuppression. The expression of CD28 and CD8+ T cells as an input layer may be a predictor of keloid severity. CD28 and CD8+ T cells play an important role in the development of keloids.

Degradation of norfloxacin (NFX) by zinc oxide (ZnO)/g-C

Nanoparticles (NPs) decorated with a high density of DNA strands, also known as spherical nucleic acids (SNAs), are widely used in DNA-programmable assembly, sensing, imaging, and therapeutics. A regular SNA synthesis is very time-consuming, which requires great caution to avoid NP aggregation. Herein we report an extremely simple, efficient, and scalable process to realize instant (in seconds) synthesis of SNAs with record-high DNA density. Our method relies on a rapid water removal from a DNA/NP mixture in contact with a butanol phase. This process generates a dehydrated "solid solution" that greatly accelerates DNA anchorage on NPs via Au-S bonding. Compared to a state-of-the-art DNA conjugation strategy in the literature, up to 3-time increase of DNA density is achieved by the instant dehydration in butanol (INDEBT). The ultradense DNA grafting is accomplished in a few seconds, which is highly hybridizable to form core-satellite assemblies. Our work turns SNA synthesis into an easy job, and enables future explorations of physical, chemical, and biological effects of SNAs with ultrahigh DNA density.

A palladium catalyzed selective C(sp3)–H arylation and acetoxylation of alcohols using a practical bidentate auxiliary were developed. Masked alcohols were selectively arylated at the β-position with diverse aryl iodides for the first time. Moreover, an efficient and site-selective acetoxylation of various primary methyl, methylene, and benzylic C(sp3)–H bonds was performed by using cheap K2S2O8 as the external oxidant.

A detailed mechanism study on the anion ligand promoted selective C–H bond fluorination is reported. The role of the anion ligand has been clarified by experimental evidence and DFT calculations. Moreover, the nitrate promoted C–F bond reductive elimination enabled a selective C–H bond fluorination of various symmetric and asymmetric azobenzenes to access diverse o-fluoroanilines.

Selective introduction of fluorine into molecules by the cleavage of inert C-H bonds is of central academic and synthetic interest, yet remains challenging. Given the central role of alcohols in organic chemistry as the most ubiquitous building blocks, a versatile and selective C(sp3 )-H and C(sp2 )-H fluorination of simple alcohols, enabled by novel designed exo-directing groups, is described. C(sp2 )-H bond fluorination was achieved by using a simple acetone oxime as auxiliary, whereas a new, modular and easily accessible bidentate auxiliary was developed for the efficient and site-selective fluorination of various primary methyl, methylene, and benzylic C(sp3 )-H bonds. Fluorinated alcohols can readily be accessed by the removal of auxiliaries, and significantly expands the synthetic prospect of the present procedure.

Herein we report a novel Cu-catalyzed regioselective C2-H alkylation of benzimidazoles with aromatic alkenes. The reaction features exclusive regioselectivity and broad substrate scope in the intermolecular alkylation of benzimidazoles with terminal and internal aromatic alkenes, constituting a modular access toward benzimidazole-containing 1,1-di(hetero)aryl alkanes. The intramolecular C2-H alkylation of benzimidazoles with aromatic alkenes has been achieved in an endo-selective manner. The enantioselective C2 alkylation of benzimidazoles has also been realized with moderate to good stereocontrol.

By employment of a rigid tripodal nitrogen-containing heterotopic ligand tris(1-imidazolyl) benzene (Htib), a new fluorescent Zn(II)-containing coordination polymer {[Zn(tib)2](NO3)2(H2O)3}n (1) with a rare two-fold interpenetrating (3,6)-connected pyr network topology has been successfully prepared under the solvothermal reaction conditions. Under the condition of visible light irradiation, rhodamine B (RhB) and methylene blue (MB) could be degraded with good performance. In the biological function study, the cytotoxicity of the synthetic was evaluated with CCK-8 detection kit on human umbilical vein endothelial cells (HUVEC). The inhibitory effect of compound on vcam-1 expression in the vascular endothelial cells was evaluated by RT-PCR. The effect of the complex on the inflammatory response in the vascular endothelial cells was determined via ELISA test of IL-1β and TNF-α. The results of pose scoring software as well as molecular docking was conducted to explore the interaction between compounds and VCAM, which might provide latent regulatory mechanisms along with binding sites for compounds.

SrTiO 3 -reduced graphene oxide (SrTiO 3 -RGO) composites were synthesized via a facile one pot hydrothermal process. This was achieved by decorating graphene oxide (GO) layers with Ti(OBu) 4 and Sr(NO 3 ) 2 as starting materials followed by hydrothermal synthesis, which converts the SrTiO 3 particles with a diameter of 87–200 nm on the RGO surface, without using strong reducing agents. The as-prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), diffuse reflectance spectra (DRS), photoluminescence spectra (PL), electrochemical impedance spectra (EIS), and photocurrent analysis. SrTiO 3 particles were shown to be grown homogeneously on the RGO sheets with close interfacial contacts. The photocatalytic hydrogen evolution activities of the SrTiO 3 and SrTiO 3 -RGO composites were contrasted. Compared to SrTiO 3 , SrTiO 3 -RGO composites showed much higher photocatalytic hydrogen production activity under UV light irradiation. The SrTiO 3 -0.8%RGO composite showed the highest photocatalytic H 2 evolution activity. PL, EIS and photocurrent analysis were used to elucidate the mechanism that the enhancement of photocatalytic hydrogen evolution activity over the SrTiO 3 -RGO composites is attributed to the reduction of the photogenerated electron-hole recombination.

Porous carbon materials have attracted considerable interest as metal-free catalysts. In this study, we report a nitrogen-doped and nanofiber-based porous carbon foam produced via an efficient and facile self-foaming approach and its subsequent pyrolysis; in this approach, carbon dioxide-rich ethanolamine serves as the foaming agent, N source and polymerization catalyst. Meanwhile resorcinol and formaldehyde are used as carbon sources. Carbon dioxide-rich ethanolamine plays a crucial role in the release of gas as well as initiating polymerization on the interfaces of bubbles, which directs the formation of polymer foam. The N-doped carbon foam can be a highly active metal-free heterogeneous catalyst to promote selective oxidation of the benzyl group to the corresponding phenone. In addition, the carbon foams are easily cast with different morphologies. Notably, the prepared carbon foam is fabricated as a monolithic reactor for the oxidation reaction, which also exhibits good catalytic performances in the scale-up experiment.

Maintaining the dispersion and stability of supported metals is still an important issue for solid catalysts that suffer from aggregation or leaching. We report an easy procedure for the preparation of Pd nanoparticles supported on carbon nanospheres by the direct pyrolysis of the metal precursor impregnated on polybenzoxazine-based polymer nanospheres. The complexation interaction between the metal and support was beneficial for the dispersion and stability of the Pd nanoparticles. Pd nanoparticles with an average size of 3 nm were uniformly dispersed on the carbon nanospheres after a thermal treatment at 500 °C under argon flow. The catalyst was evaluated for aerobic benzyl alcohol oxidation under mild conditions without using a base additive. In order to get mostly outer surface Pd nanoparticles, the catalyst preparation conditions were investigated by varying the metal loading and loading time. The highest catalytic activity reached a TOF of 690 h −1 when the catalyst was prepared under the optimized conditions. The catalyst also showed good recyclability and can be easily regenerated by calcination at 200 °C.

The bimetallic Fe–Cu/O 2 process exhibited significantly higher reactivity than did the Fe/O 2 process for the degradation of ethylenediaminetetraacetic acid (EDTA). With the analysis of the soluble Cu 2+ in the solution and decomposition of H 2 O 2 catalyzed by Cu 0 , possible enhanced-pathways at different pHs were suggested. The degradation efficiency of EDTA increased with decreasing initial pH ranging 3–9, however, the reactions proceeded at a weakly-basic to basic condition in most of the reaction time. POD inhibition test showed that in situ generation of H 2 O 2 played a pivotal role in the EDTA degradation, however, the instant concentration analyzed by DPD–POD method was less than 4.5 μM due to rapid subsequent Fenton reaction. Furthermore, DMPO–ESR spectroscopy and BA-trapping experiments detected the in situ generation of OH. The mechanism of EDTA oxidative degraded by the bimetallic Fe–Cu/O 2 process was verified using control experiments of absorption, stripping, and coagulation sedimentation of EDTA in the system, analysis of solid residue, oxidation of O 2 and H 2 O 2 , as well as detection of H 2 O 2 and OH.

Immobilized Cu(OAc)(2)-bis(oxazolines) via hydrogen bonding by SBA-15 was applied to asymmetric Henry reaction, and good enantioselectivities were obtained (up to 83% ee) between 2-methoxybenzaldehyde and CH(3)NO(2) in isopropyl alcohol (iPrOH). The catalyst could be reused seven times without any obvious loss in enantioselectivity. For the first time, this facile and clean immobilization method is applied to the use of bis(oxazolines) complexes.

Porous silica with different nanostructures, namely two-dimensional hexagonal SBA-15, three-dimensional cubic KIT-6 and hierarchical monolith silica (HMS), were used as supports to fabricate gold catalysts using a liquid-phase deposition–precipitation method. Pre-loading of ceria on porous silica can significantly improve the dispersion of the subsequently introduced gold nanoparticles and the catalytic activity of the final composite (Au/CeO2/SiO2) catalysts in CO oxidation. The composite catalysts were characterized by N2 adsorption, X-ray diffraction. The results indicate that different nanostructures of silica imposed significant influence on the catalytic activity of Au/CeO2/SiO2 catalysts. Gold catalyst supported on HMS exhibited the highest activity for the conversion of CO to CO2 with a complete conversion (T100%) at a temperature of 60 °C and at a space velocity of 80,000 mL gcat−1 h−1, whereas T100% shifted to 120–130 °C for SBA-15 and KIT-6 supported gold catalysts.

Through bioassay-guided fractionation of the extracts from the aerial parts of the Chinese herb Hypericum japonicum Thunb. Murray, Isojacareubin (ISJ) was characterized as a potent antibacterial compound against the clinical methicillin-resistant Staphylococcus aureus (MRSA). The broth microdilution assay was used to determine the minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) of ISJ alone. The results showed that its MICs/MBCs ranged from 4/16 to 16/64 μg/mL, with the concentrations required to inhibit or kill 50% of the strains (MIC(50)/MBC(50)) at 8/16 μg/mL. Synergistic evaluations of this compound with four conventional antibacterial agents representing different types were performed by the chequerboard and time-kill tests. The chequerboard method showed significant synergy effects when ISJ was combined with Ceftazidime (CAZ), Levofloxacin (LEV) and Ampicillin (AMP), with the values of 50% of the fractional inhibitory concentration indices (FICI(50)) at 0.25, 0.37 and 0.37, respectively. Combined bactericidal activities were also observed in the time-kill dynamic assay. The results showed the ability of ISJ to reduce MRSA viable counts by log(10)CFU/mL at 24 h of incubation at a concentration of 1 × MIC were 1.5 (LEV, additivity), 0.92 (CAZ, indifference) and 0.82 (AMP, indifference), respectively. These in vitro anti-MRSA activities of ISJ alone and its synergy with conventional antibacterial agents demonstrated that ISJ enhanced their efficacy, which is of potential use for single and combinatory therapy of patients infected with MRSA.

New imidazolium/pyrrolidinium-tagged Indabox ligands were designed and prepared. Catalysts based on these ligands with Cu(OAc) 2 ·H 2 O were applied to the asymmetric Henry reaction using various aldehydes and CH 3 NO 2 , the products were obtained in high enantioselectivity. Specifically, ( R )-1-(2-methoxylphenyl)-2-nitroethanol was obtained in 94% ee in MeOH. Furthermore, the catalyst based on 7 could be recycled at least 12 times by simple wash without an obvious loss of activity or enantioselectivity. This catalytic procedure demonstrated the potential for catalyst recyclability in the asymmetric Henry reaction. Additionally, a theoretical mechanistic study was conducted to explain the origin of the enantioselectivity.

The hydrosilylation of alkenes with triethoxysilane has been achieved at 120 °C in the presence of 0.01 mol% of thioether-functionalized MCM-41 anchored rhodium complex, affording the corresponding addition products in 68–91% yields. This supported rhodium complex can be reused several times without noticeable loss of activity. Our system not only solves the basic problems of catalyst separation and recovery, but also avoids the use of phosphine ligands.

A novel bisabolane-type sesquiterpenoid lactone, glochicoccin A (1), and three new norbisabolane sesquiterpenoids, glochicoccins B-D (2-4), together with two known norbisabolane sesquiterpenoids, phyllaemblic acid (5) and phyllaemblic acid methyl ester (6), were isolated from the rhizomes of Glochidion coccineum. Their structures were elucidated by different spectroscopic (IR, UV, NMR) and mass-spectrometric (MS) techniques. The structure and relative configuration of I was confirmed by single-crystal X-ray diffraction (Fig. 2). None of the compounds were found to exhibit cytotoxic or antioxidant activities.

(25R)-5a-Spirostan-2a,3b-diol (gitogenin) 3β-O-[2-O-(α-L-rhamnopyranosyl)-β-D-galactopyranoside] (1), a cytotoxic spirostan saponin isolated from the underground parts of Hosta longipes (Liliaceae), was concisely synthesized. In this context, its congeners 2-4 were also prepared. All four compounds showed comparable potency to dioscin in inhibition against the growth of tumor cells.

Nitrogen-doped carbon nanotubes are synthesized by the pyrolysis of CH 3 CN with/without H 2 over MgO supported Fe catalysts at 850 °C in argon flow. In both cases nitrogen is introduced to dope the product with quite different amount. TG analysis, Raman spectroscopy, SEM and TEM results showed that the introduction of H 2 is favorable for the formation of multi-walled nanotubes (MWNTs) containing less nitrogen.

A simple method for the synthesis of metal oxide thin films through gel solutions of inorganic metal salts using poly(ethylene glycol) was developed. The technique was then applied to fabricate nanoscale MgO-supported catalysts for the surface CVD growth of single-wall carbon nanotubes (SWNTs.) The results showed that the catalytic films greatly promoted the growth of SWNTs of high quality, density, and uniformity. The bundle sizes, growth density, and orientation of the resulting SWNTs could be controlled to some extent by choosing the type of catalyst and by suitable modification of the reaction parameters.

The new bisoxazoline promotes the reaction of a number of aldehydes with nitromethane and nitroethane.

Functional imidazolium ionic liquids have been developed as a new class of versatile catalysts. C(2)-symmetric imidazolium-tagged bis(oxazoline) ligands were prepared, and the anions of the ligands were altered. The catalysts based on the new ligands and Cu(OAc)(2)·H(2)O were applied in asymmetric Henry reactions between various aldehydes 3 and CH(3)NO(2)4. The catalysts achieved a high level of enantioselectivity; product (R)-5n was attained at 94% ee in MeOH. Moreover, the catalyst could be recycled 6 times without an obvious loss of activity or enantioselectivity. In addition, a theoretical mechanistic study was conducted to explain the origin of the enantioselectivity.

On the basis of benzoxazine chemistry, we have established a new way to synthesize highly uniform carbon nanospheres with precisely tailored sizes and high monodispersity. Using monomers including resorcinol, formaldehyde, and 1,6-diaminohexane, and in the presence of Pluronic F127 surfactant, polymer nanospheres are first synthesized under precisely programmed reaction temperatures. Subsequently, they are pseudomorphically and uniformly converted to carbon nanospheres in high yield, due to the excellent thermal stability of such polybenzoxazine-based polymers. The correlation between the initial reaction temperature (IRT) and the nanosphere size fits well with the quadratic function model, which can in turn predict the nanosphere size at a set IRT. The nanosphere sizes can easily go down to 200 nm while retaining excellent monodispersity, i.e., polydispersity5%. The particle size uniformity is evidenced by the formation of large areas of periodic assembly structure. NMR, FT-IR, and elemental analyses prove the formation of a polybenzoxazine framework. As a demonstration of their versatility, nanocatalysts composed of highly dispersed Pd nanoparticles in the carbon nanospheres are fabricated, which show high conversion and selectivity, great reusability, and regeneration ability, as evidenced in a selective oxidation of benzyl alcohol to benzaldehyde under moderate conditions.

A new strategy in which the anchoring group is separated from the acceptor groups of the dyes was developed; among these dyes, the HY103 dye gives a maximum IPCE value of 86% at 660 nm and an eta value of 3.7% in the NIR region reported in DSCs.

Functional imidazolium ionic liquids have been developed as a new class of versatile catalysts. C2-symmetric and unsymmetric imidazolium-tagged bis(oxazoline) ligands were prepared, and the anions of the ligands were altered by ion-exchange reactions. The catalysts based on the new ligands and Cu(OTf)2 were applied in asymmetric Diels–Alder reactions between N-acryloyl/N-crotonoyloxazolidinones 15 and 1,3-cyclohexandiene/cyclopentadiene 16 in different ionic liquids and in dichloromethane (DCM). The catalysts achieved a high level of activity and enantioselectivity, as well as good recyclability: cycloadduct (S)-17ab was attained at 98% conversion and 97% ee in [Bmim]NTf2. Moreover, the catalyst could be recycled 20 times without an obvious loss of activity or enantioselectivity. By comparison, we deduced that the C2 symmetry of the new ligands was crucial for obtaining high ee values. Toxicity studies of the ligands were performed for the first time.