An iridium-catalyzed allylation/esterification cascade reaction of spirotetramic acid derivatives has been developed, affording chiral 3-allylic spirotetramic acid ester derivatives with excellent enantioselectivity (94-99% ee) in moderate to high yields (43-97%). Meanwhile, a sequential iridium- and cinchona alkaloid-catalyzed double allylations reaction was established, yielding chiral 3-allylic spirotetramic acid derivatives bearing two stereogenic centers with excellent enantioselectivity (99% ee) and moderate to high diastereoselectivity (4:1 to >20:1 dr) in moderate to good yields (43-70%). The target compound 4d exhibited promising insecticidal activity against Aphis craccivora, with the activity of (S)-4d (LC50 = 0.094 g·L-1) being significantly higher than that of (R)-4d (LC50 = 0.174 g·L-1) and its racemate (LC50 = 0.178 g·L-1).

The development of highly efficient oxygen evolution reaction (OER) electrocatalysts is essential for the sustainable production of clean hydrogen energy via proton-exchange membrane (PEM) water electrolysis. Ruthenium (Ru)-based catalysts are promising cost-effective alternatives to iridium (Ir)-based catalysts for acidic OER, yet the trade-off between activity and stability hinders their further optimization. Here, we report a metal-organic framework (MOF) precursor-mediated strategy to synthesize the Ru/RuMnMoO2 heterostructure catalyst. X-ray absorption fine structure, electrochemical evaluation, and theoretical calculation results demonstrated that doped Mn stabilized the lattice oxygen, while Mo promoted electron transfer to Ru, thereby suppressing the peroxide-induced Ru leaching. As expected, the Ru/RuMnMoO2 requires only 163 mV of overpotential to achieve 10 mA cmgeo-2 in acidic electrolyte and maintains long-term stability over 3000 h. Cation probe tests and density functional theory (DFT) calculations confirmed that Ru/RuMnMoO2 followed an adsorbate evolution mechanism (AEM). Notably, a PEM electrolyzer using Ru/RuMnMoO2 as the anode can deliver an ampere-level current density of 1.0 A cmgeo-2 at 1.70 V with a low Ru loading (0.59 mgRu cm-2), outperforming the commercial RuO2-based PEM electrolyzer (2.31 V@ 1.14 mgRu cm-2). Moreover, the cell can stably run for 240 h at a high current density of 3 A cmgeo-2, demonstrating its significant practical potential for alleviating the dependence on iridium.

This study tackles the dual challenges of sluggish oxygen evolution reaction (OER) kinetics and excessive iridium loading in proton exchange membrane water electrolysis (PEMWE) via rational catalyst design. Through a rapid synthesis strategy, it is anchored ultrafine IrOx nanoparticles (<3 nm) on K2Ti8O17 (KTO), achieving exceptional acidic OER activity with ultra-low Ir content (10.89 wt.%). The IrOx/KTO-1 catalyst exhibits 4.4x higher mass activity than IrO2 in acidic OER. In PEMWE cells, it delivers 3 A cm(-2) at 1.79 V (44.0 kWh kg(-1)) and sustains >550 h at 1000 mA cm(-2) (H-2 cost: $0.88 kg(-1), 56% below US-DOE 2026 target). Crucially, it maintains stability for 500 h at 3000 mA cm(-2) and strong operational reliability under volatile renewable energy inputs, showcasing its potential for industrial-scale implementation. In situ Raman spectroscopy, X-ray analyses, and DFT calculations reveal that interfacial charge redistribution between KTO and sub-nano IrOx dynamically activates Ir sites during OER, accelerates charge transfer, and reduces the OER reaction barrier. The synergy of size-controlled active sites and defect-mediated electronic modulation enables simultaneous high activity, stability, and industrial current density tolerance. This work establishes a paradigm for designing confinement-stabilized nanocatalysts toward practical green hydrogen production.

This work introduces a novel α,α-diester-δ-vinylvalerolactone as a dipolar precursor in a palladium-catalyzed [6 + 4] cycloaddition reaction with azadienes, resulting in the production of ten-membered heterocycles.

The intermolecular [4 + 2] cycloaddition of o-hydroxy benzyl alcohols with isochroman ketals was realized by CF3CO2H catalysis. A broad range of bisbenzannulated [6,6]-spiroketals were formed under the metal-free mild conditions in moderate to excellent yields (45-98%) with mostly excellent diastereoselectivities (up to >20 : 1 dr). Furthermore, the enantioselective version was also preliminarily investigated and the bisbenzannulated [6,6]-spiroketal was obtained with 61% ee in the presence of Sc(OTf)(3)/Feng's chiral N,N '-dioxide ligand. Some of the bisbenzannulated [6,6]-spiroketal products showed good in vitro antifungal activities against Sclerotinia sclerotiorum and Rhizoctonia solani.

Proton-exchange-membrane water electrolyzer (PEMWE) catalyst layers consist of aggregates of catalyst particles (typically iridium) and ionomer (typically Nafion). Prior work suggests that the oxide form of Ir affects the kinetics of the oxygen-evolution reaction. However, because most catalyst-benchmarking studies are conducted ex situ in liquid electrolytes, it remains unclear how the ionomer is influenced by the catalyst oxide and affects overall cell performance. Using a suite of experimental techniques, we conduct fundamental investigations into model ink (catalyst and ionomer dispersed in solution) and thin-film systems to inform cell-level overpotential analysis as a function of three forms of Ir (metallic Irm, oxyhydroxide IrOOH, and oxide IrO2). Nafion on Irm has a high degree of phase separation and higher swelling, likely improving the ionic conductivity. Additionally, Nafion binds most strongly to IrOOH, likely yielding reduced kinetic overpotentials. These findings highlight the intricacies of the ionomer/Ir interface and provide insight into all catalyst-layer systems.

We developed a novel Pd-catalyzed [4 + 4] cycloaddition of benzofuran-derived azadienes with homo-TMM all-carbon 1,4-dipoles in situ generated from α-allyl malonate derivatives, affording an array of benzofuro[3,2-b]azocines with good to excellent yields (up to 96%) and exclusive regioselectivities. This methodology featured mild reaction conditions and good functional group tolerance. The synthetic utility was demonstrated by a gram-scale reaction. Furthermore, the catalytic asymmetric [4 + 4] cycloaddition version has also been explored.

We developed a novel Pd-catalyzed[4+4]cycloaddition of(benzo)furan-derived azadienes with homo-TMM all-carbon 1,4-dipoles in situ generated from α-allyl malonate derivatives,affording an array of benzofuro[3,2-b]azocines and furo[3,2-b]azocines with good to excellent yields(up to 96％)and exclusive regioselectivities.This methodology featured mild reaction conditions and good func-tional group tolerance.The synthetic utility was demonstrated by a gram-scale reaction.Furthermore,the catalytic asymmetric[4+4]cycloaddition version has also been explored.

Alkaline anion-conducting polymer-based CO2 electrolysis and water electrolysis are among two emerging renewable energy conversion technologies. Their system design and integration offer promise of lower capital cost due to utilization of low-cost catalysts, in contrast to platinum group metal catalysts required for cation-conducting polymer-based devices. However, a critical component, the polymer electrolyte membrane, remains an obstacle hampering system performance and durability. In this study, commercially-available Sustainion® membranes with and without PTFE-reinforcement were investigated to understand previously unreported origins of improved device performance when compared to alternative membrane chemistries. We report critical membrane properties, such as morphology, thermal stability, as well as temperature-, hydration-, and counter-ion dependent ion conductivity. Moveover, the changes in uptake and conductivity of membranes in supporting electrolytes of K2CO3 and KOH investigated as a function of their concentration. Presence of reinforcement and supporting electrolyte type alter the membrane's transport functionality, which could help guide device design for improved performance. The obtained results not only show how Sustainion® properties change with operating environment for CO2 and water electrolysis applications, but also provide understanding for internal and external factors controlling anion-exhcnage membrane functionality in electrochemical devices.

A reversed-phase isocratic elution high-performance liquid chromatography method coupled with fluorescence detection has been developed to determine urea concentration via online postcolumn derivatization. Swimming pool water samples were filtered through 0.20 μm syringe filters. When the temperature of reaction coil was 40°C, urea was derivatized well with xanthydrol methanol solution (0.1 g/L) containing 0.50% hydrochloric acid with a flow rate of 0.20 mL/min. Successful separation was achieved by using Shim-pack VP-ODS C18 (250 mm × 4.6 mm, 5 μm) column, with a mobile phase containing phosphoric acid solution (0.01 mol/L) at a flow rate of 0.80 mL/min. Retention time and external standard method were used for qualitative and quantitative urea analysis, respectively. Under the established conditions, the limit of detection, linear range, correlation coefficient, recovery and relative standard deviation was 0.09 mg/L, 1.0-100.0 mg/L, 0.9998, 87.0-105.3% and 0.95-4.8%, respectively. Ammonia, thiourea and trichloroisocyanuric acid did not interfere with urea analysis. The method showed satisfactory results with high precision, accuracy, recovery, as well as sensitivity, for the determination of urea in swimming pool water.

A Pd-catalyzed decarboxylation strategy for the efficient synthesis of cyclohepta[b]indoles in good yields with good to excellent enantioselectivities and moderate diastereoselectivities is reported.In this procedure,viny indoloxazolidones were activated by Pd catalyst to generate zwitterionic intermediates in situ,which were then trapped by the electro-deficient diene species via the asymmetric[3+4]cycloaddition process.

The enantioselective cascade reaction between racemic 2-(1-hydroxyallyl)phenols and alkynols/alkynamides was realized by using a gold and iridium sequential catalytic system. In this procedure, the in situ generated exocyclic vinyl ethers or enamides undergo the asymmetric allylation/spiroketalization with π-ally-Ir amphiphilic species, which provides an efficient and straightforward access to spiroketals and spiroaminals with excellent enantioselectivities. Moreover, racemic 2-(1-hydroxyallyl)anilines were also suitable in this reaction along with a kinetic resolution process, affording enantioenriched spiroaminals and 2-(1-hydroxyallyl)anilines in good yields. The synthetic utility of this method has been demonstrated by efficient enantioselective synthesis of the analogue of Paecilospirone.

We reported herein an iridium/silver/acid ternary catalytic system to access bisbenzannulated [6,6]-spiroketals in high efficiency with generally high diastereo- and enantioselectivities (up to >20 : 1 dr, >99 % ee). In this procedure, readily available o-alkynylacetophenones undergo cycloisomerization to generate isochromenes in situ that participate in stereoselective allylation/spiroketalization sequence with 2-(1-hydroxyallyl)phenols. Meanwhile, 2-(1-hydroxyallyl)anilines were also compatible in this cascade reaction, furnishing structurally novel bisbenzannulated [6,6]-spiroaminals with good diastereoselectivities (8 : 1-12 : 1 dr) and excellent enantioselectivities (98 %->99 % ee). Moreover, experimental studies and theoretical calculations were performed to illustrate the reaction mechanism and stereochemistry.

Ionomers are used as the solid-electrolyte in many electrochemical energy conversion technologies where they offer many functionalities such as ion conduction, electrical insulation, and water transport. These ionomers are found as nanometer-thick electrolyte thin films within the catalyst layers of fuel cells, electrolyzers, and hydrogen-based redox flow batteries where electrochemical reactions take place. The ionomer performance and durability are strongly related to their properties governed by a myriad of parameters such as chemical structure, water uptake, and morphology, all of which are stimulated differently by the external environment. Typically, the ionomer consists of the same ion-conducting polymer used as the electrode separator but exhibit disparate properties from the bulk membrane when nanometer thickness coatings are confined to a hard substrate (as in a catalyst layer), where the behavior is influenced by the ionomer affinity with the air and hard interfaces. Two motifs of ionomers exist, one as an acidic polymer (e.g. Nafion) and the alternative, and less studied, alkaline polymer (e.g. Sustainion). This talk will focus on filling in the gaps between the disparate properties of alkaline ionomers in the thin film motif that have been extensively studied for acidic ionomers. Aspects such as different backbones (e.g. perfluorinated, aliphatic, aromatic) and side chains (e.g. length, functional group) are explored in X-ray scattering, hydration, and transport measurements. Small-angle X-ray scattering is used to probe the morphology of these different polymer thin-films. Quartz crystal microbalance and spectroscopic ellipsometry under different states of humidity are used to probe hydration and free volume. The resulting correlations provide insights on not only how different polymer respond to the confined environment but how chemistry can be tuned to boost performance in alkaline electrochemical energy devices.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants of great health concern. Epidemiological and animal studies have revealed the carcinogenic and mutagenic risk of PAHs, and therefore avoiding PAH exposure is a high priority. In this work, a comparison of liquid-liquid, solid-phase, and supported -liquid extraction was conducted for detecting PAHs in serum samples. The key features of mechanism, simplicity, recoveries, and background interference were compared for the three procedures. Solid-phase and supported -liquid extraction showed chromatography background interference and required method optimization to obtain satisfactory recoveries that were comparable to that of liquid-liquid extraction. Liquid-liquid extraction with hexane and high-performance liquid chromatography coupled with a fluorescence detection was employed for detecting PAHs in serum samples. The limits of quantification of the individual PAHs ranged from 16.0 ng/L to 40.0 ng/L, and recoveries were obtained from 69.6 % to 87.7 %. The method was used for human bio-monitoring of the target PAHs in the serum of 120 volunteers from Guangzhou. The mean total PAH concen-tration in the serum of adults (2.60 mu g/L) was significantly higher than that of teenagers (1.69 mu g/L). The total estimated daily intake of PAHs was calculated for naphthalene, fluorene, and phenanthrene, and a low health risk was obtained by the evaluation of their non-carcinogenic and carcinogenic risks.