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Developing new strategies to enable chemo- and regioselective reductions is an important topic in chemical research. Herein, an efficient and regioselective Pd/IPr BIDEA -catalyzed ring-opening hydrodefluorination of gem -difluorocyclopropanes to access terminal fluoroalkenes is developed. The success of this transformation was attributed to the use of 3,3-dimethylallyl Bpin as a novel hydride donor. DFT calculations suggest that a direct 3,4'-hydride transfer via a 9-membered cyclic transition state is more favorable, which combined with the irreversibility of the reaction enables the unusual selectivity for the less thermodynamically stable terminal alkene isomer. This reaction mode is also applicable to a variety of regioselective allylic and propargyl reductions.

Purpose: Airway remodeling is a significant pathological change of asthma. This study aimed to detect differentially expressed microRNAs in the serum of asthma patients and airway smooth muscle cells (ASMCs) of asthmatic mice, exploring their role in the airway remodeling of asthma., Methods: The differentially expressed microRNAs in the serum of mild and moderate-severe asthma patients compared to healthy subjects were revealed using the "limma" package. Gene Ontology (GO) analysis was used to annotate the functions of microRNA target genes. The relative expressions of miR-107 (miR-107-3p in mice sharing the same sequence) in the primary airway smooth muscle cells (ASMCs) of the asthma mice model were tested by RT-qPCR. Cyclin-dependent kinases 6 (Cdk6), a target gene of miR-107, was predicted by algorithms and validated by dual-luciferase reporter assay and Western blot. The roles of miR-107, Cdk6, and protein Retinoblastoma (Rb) in ASMCs were examined by transwell assay and EDU KIT in vitro., Results: The expression of miR-107 was down-regulated in both mild and moderate-severe asthma patients. Intriguingly, the level of miR-107 was also decreased in ASMCs of the asthma mice model. Up-regulating miR-107 suppressed ASMCs' proliferation by targeting Cdk6 and the phosphorylation level of Rb. Increasing the expression of Cdk6 or suppressing Rb activity abrogated the proliferation inhibition effect of ASMCs induced by miR-107. In addition, miR-107 also inhibits ASMC migration by targeting Cdk6., Conclusion: The expression of miR-107 is down-regulated in serums of asthma patients and ASMCs of asthmatic mice. It plays a critical role in regulating the proliferation and migration of ASMCs via targeting Cdk6., Competing Interests: The authors report no conflicts of interest in this work., (© 2023 Xiong et al.)

Photoelectrochemical reaction is emerging as a powerful approach for biomass conversion. However, it has been rarely explored for glucose conversion into value-added chemicals. Here we develop a photoelectrochemical approach for selective oxidation of glucose to high value-added glucaric acid by using single-atom Pt anchored on defective TiO 2 nanorod arrays as photoanode. The defective structure induced by the oxygen vacancies can modulate the charge carrier dynamics and band structure, simultaneously. With optimized oxygen vacancies, the defective TiO 2 photoanode shows greatly improved charge separation and significantly enhanced selectivity and yield of C 6 products. By decorating single-atom Pt on the defective TiO 2 photoanode, selective oxidation of glucose to glucaric acid can be achieved. In this work, defective TiO 2 with single-atom Pt achieves a photocurrent density of 1.91 mA cm -2 for glucose oxidation at 0.6 V versus reversible hydrogen electrode, leading to an 84.3 % yield of glucaric acid under simulated sunlight irradiation., (© 2023. The Author(s).)

The incorporation of a germyl group and another functional fragment across the C═C bond is a challenging task due to the prevailing hydrogermylation reaction. Herein, an efficient copper-catalyzed three-component reaction of alkenes, germanium hydrides, and trimethylsilyl azide has been disclosed. This transformation allows the concomitant introduction of germyl and azide groups across the double bonds in a highly regioselective manner with tert -butyl hydroperoxides as the bystanding oxidant. The resulting β-germyl azides could be easily converted into β-germyl amine and 1,2,3-triazoles of significant value.

The concurrent incorporation of a germyl fragment and another functional group (beyond the hydrogen atom) across the C═C double bond is a highly appealing yet challenging task. Herein we demonstrate the efficient germyl peroxidation of alkenes with germanium hydrides and tert -butyl hydroperoxide via a copper-catalyzed three-component radical relay strategy. This protocol exhibits excellent functional group tolerance and exquisite chemo- and regioselectivity under mild conditions and represents a rare example of constructing synthetically challenging metal-embedded organic peroxides.

The development of methods for the assembly of 1,2,3-triazoles is an important topic due to the broad applications of this motif in various scientific fields. In this work, we demonstrate that the three-component assembly of α-CF 3 carbonyls, NaN 3 , and amines was achieved for the selective construction of a variety of 5-amino NH -1,2,3-triazoles under transition-metal-free and open-air conditions. The method provides a general and operationally simple route to functionalized biologically important molecules including carbohydrates, nucleosides, and peptides and exhibits broad substrate scopes. We further demonstrate that the NH -1,2,3-triazoles can be smoothly converted to the regiospecific N -2 alkylated 1,2,3-triazole products. Mechanistic studies based on experiments and density functional theory calculations showed that this transformation proceeds via defluorination-initiated programmed substitution/cyclization/H-transfer to give the 4,5-difunctionalized captodative NH -1,2,3-triazole product.

A simple and efficient strategy for iron-catalysed cascade radical cyclization was developed, by which an array of germanium-substituted indolo[2,1- a ]isoquinolin-6(5 H )-ones and indolin-2-ones were obtained in one pot with germanium hydrides as radical precursors. A rapid intramolecular radical trapping mode enabled the selective arylgermylation of alkenes over the prevalent hydrogermylation reaction.

Lithium-oxygen batteries with ultrahigh energy densities have drawn considerable attention as next-generation energy storage devices. However, their practical applications are challenged by sluggish reaction kinetics aimed at the formation/decomposition of discharge products on battery cathodes. Developing effective catalysts and understanding the fundamental catalytic mechanism are vital to improve the electrochemical performance of lithium-oxygen batteries. Here, uniformly dispersed ruthenium nanoparticles anchored on nitrogen-doped reduced graphene oxide are prepared by using an in situ pyrolysis procedure as a bifunctional catalyst for lithium-oxygen batteries. The abundance of ruthenium active sites and strong ruthenium-support interaction enable a feasible discharge product formation/decomposition route by modulating the surface adsorption of lithium superoxide intermediates and the nucleation and growth of lithium peroxide species. Benefiting from these merits, the electrode provides a drastically increased discharge capacity (17,074 mA h g -1 ), a decreased charge overpotential (0.51 V), and a long-term cyclability (100 cycles at 100 mA g -1 ). Our observations reveal the significance of the dispersion and coordination of metal catalysts, shedding light on the rational design of efficient catalysts for future lithium-oxygen batteries.

Li-O 2 batteries (LOB) are considered as one of the most promising energy storage devices using renewable electricity to power electric vehicles because of its exceptionally high energy density. Carbon materials have been widely employed in LOB for its light weight and facile availability. In particular, graphene is a suitable candidate due to its unique two-dimensional structure, high conductivities, large specific surface areas, and good stability at high charge potential. However, the intrinsic catalytic activity of graphene is insufficient for the sluggish kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in LOB. Therefore, various surface functionalization schemes for graphene have been developed to tailor the surface chemistry of graphene. In this review, the properties and performances of functionalized graphene cathodes are discussed from theoretical and experimental aspects, including heteroatomic doping, oxygen functional group modifications, and catalyst decoration. Heteroatomic doping breaks electric neutrality of sp 2 carbon of graphene, which forms electron-deficient or electron-rich sites. Oxygen functional groups mainly create defective edges on graphene oxides with C-O, C=O, and -COO-. Catalyst decoration is widely attempted by various transition and precious metal and metal oxides. These induced reactive sites usually improve the ORR and/or OER in LOB by manipulating the adsorption energies of O 2 , LiO 2 , Li 2 O 2 , and promoting electron transportation of cathode. In addition, functionalized graphene is used in anode and separators to prevent shuttle effect of redox mediators and suppress growth of Li dendrite.

Organoarsenicals remediation requires degrading organoarsenicals and simultaneously immobilizing the resulted inorganic arsenic, and is thus a great challenge. In this study, a simulated solar light driven Fe(III)/Fe(II) cycle strategy was developed to degrade roxarsone and immobilize the generated inorganic arsenic via tuning the degree of Fe(III) hydrolysis. At pH values of 2.0 and 3.0, the hydrolysis of Fe(III) in the solution was suppressed to produce photoreactive Fe(III)-hydroxyl complexes, which could be excited by simulated solar light to generate OH for 85.3 % of roxarsone degradation into arsenate within 60 min. Density functional theory calculations suggested that Fe(OH)(H 2 O) 5 2+ with lower energy separation gap was the most photoactive Fe(III)-hydroxyl complex for OH generation. With further increasing pH value to 6.0, the hydrolysis of Fe(III) was promoted to precipitate the arsenate for its immobilization, accompanying with the decrease of final iron ions and arsenate concentrations to 0.012 mmol L -1 and 58 μg L -1 , respectively. Meanwhile, the undegraded roxarsone was also adsorbed by the precipitate, increasing the overall roxarsone removal efficiency to 99.0 %. This study offers a promising strategy for the efficient organoarsenicals treatment, and also sheds light on the dual effects of iron based materials in organic pollutants degradation and heavy metal ions immobilization., Competing Interests: Declaration of Competing Interest The authors declare no competing financial interest., (Copyright © 2019. Published by Elsevier B.V.)

A novel tandem catalysis system consisted of salicylaldiminato binuclear/mononuclear titanium and 2,6-bis(imino)pyridyl iron complexes was developed to catalyze ethylene in-situ copolymerization. Linear low-density polyethylene (LLDPE) with varying molecular weight and branching degree was successfully prepared with ethylene as the sole monomer feed. The polymerization conditions, including the reaction temperature, the Fi/Ti molar ratio, and the structures of bi- or mononuclear Ti complexes were found to greatly influence the catalytic performances and the properties of obtained polymers. The polymers were characterized by differential scanning calorimetry (DSC), high temperature gel permeation chromatography (GPC) and high temperature 13 C NMR spectroscopy, and found to contain ethyl, butyl, as well as some longer branches. The binuclear titanium complexes demonstrated excellent catalytic activity (up to 8.95 × 10 6 g/molTi·h·atm) and showed a strong positive comonomer effect when combined with the bisiminopyridyl Fe complex. The branching degree can be tuned from 2.53 to 22.89/1000C by changing the reaction conditions or using different copolymerization pre-catalysts. The melting points, crystallinity and molecular weights of the products can also be modified accordingly. The binuclear complex Ti 2 L 1 with methylthio sidearm showed higher capability for comonomer incorporation and produced polymers with higher branching degree and much higher molecular weight compared with the mononuclear analogue.

Conducting polyaniline (PANI) exhibits interesting properties, such as high conductivity, reversible convertibility between redox states, and advantageous structural feature. It therefore receives ever-increasing attention for various applications. This Minireview evaluates recent studies on application of PANI for Li-ion batteries (LIBs), Li-S batteries (LSBs) and supercapacitors (SCPs). The flexible PANI is crucial for cyclability, especially for buffering the volumetric changes of electrode materials, in addition to enhancing the electron/ion transport. Furthermore, PANI can be directly used as an electroactive component in electrode materials for LIBs or SCPs and can be widely applied in LSBs due to its physically and chemically strong affinity for S and polysulfides. The evaluation of studies herein reveals significant improvements of electrochemical performance by physical/chemical modification and incorporation of PANI., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)