bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organo‐Photocatalytic Anti‐Markovnikov Hydroamidation of Alkenes with Sulfonyl Azides: A Combined Experimental and Computational Study
Authors: Fu Rui , Xu Mengyu , Wang Yujing , Wu Xinxin , Bao Xiaoguang 
Published: April 2024

AbstractThe construction of C(sp3)−N bonds via direct N‐centered radical addition with olefins under benign conditions is a desirable but challenging strategy. Herein, we describe an organo‐photocatalytic approach to achieve anti‐Markovnikov alkene hydroamidation with sulfonyl azides in a highly efficient manner under transition‐metal‐free and mild conditions. A broad range of substrates, including both activated and unactivated alkenes, are suitable for this protocol, providing a convenient and practical method to construct sulfonylamide derivatives. A synergistic experimental and computational mechanistic study suggests that the additive, Hantzsch ester (HE), might undergo a triplet‐triplet energy transfer manner to achieve photosensitization by the organo‐photocatalyst under visible light irradiation. Next, the resulted triplet excited state 3HE* could lead to a homolytic cleavage of C4−H bond, which triggers a straightforward H‐atom transfer (HAT) style in converting sulfonyl azide to the corresponding key amidyl radical. Subsequently, the addition of the amidyl radical to alkene followed by HAT from p‐toluenethiol could proceed to afford the desired anti‐Markovnikov hydroamidation product. It is worth noting that mechanistic pathway bifurcation could be possible for this reaction. A feasible radical chain propagation mechanistic pathway is also proposed to rationalize the high efficiency of this reaction.
A Zeolitic Octahedral Metal Oxide with Ultrahigh Porosity for High‐temperature and High‐humidity Alkyne/Alkene Separation
Authors: Ma Baokai , Hu Panpan , Zou Liangcheng , Zhu Qianqian , Zhang Lifeng , Ishikawa Satoshi , Ueda Wataru , Li Yanshuo , Zhang Zhenxin 
Published: April 2024

AbstractZeolitic octahedral metal oxide is a newly synthesized all‐inorganic zeolitic material and has been used for adsorption, separation, and catalysis. Herein, a new zeolitic octahedral metal oxide was synthesized and characterized. The porous framework was established through the assembly of [P2Mo13O50] clusters with PO4 linkers. Guest molecules occupied the framework, which could be removed through heat treatment, thereby opening the micropores. The pore characteristics were controlled by the cations within the micropore, enabling the adjustment of the interactions with alkynes and alkenes. This resulted in good separation performance of ethylene/acetylene and propylene/propyne even under high temperature and humidity conditions. The high stability of the material enabled the efficient recovery and reuse without discernible loss in the separation performance. Due to the relatively weak interaction between the adsorbed alkyne and the framework, the adsorbent facilitated the recovery of a highly pure alkyne. This feature enhances the practical applicability of the material in various industrial processes.
SilE‐R and SilE‐S—DABB Proteins Catalysing Enantiospecific Hydrolysis of Organosilyl Ethers
Authors: Pick Lisa M. , Oehme Viviane , Hartmann Julia , Wenzlaff Jessica , Tang Qingyun , Grogan Gideon , Ansorge‐Schumacher Marion B. 
Published: April 2024

AbstractSilyl ethers fulfil a fundamental role in synthetic organic chemistry as protecting groups and their selective cleavage is an important factor in their application. We present here for the first time two enzymes, SilE−R and SilE−S, which are able to hydrolyse silyl ethers. They belong to the stress‐response dimeric A/B barrel domain (DABB) family and are able to cleave the Si−O bond with opposite enantiopreference. Silyl ethers containing aromatic, cyclic or aliphatic alcohols and, depending on the alcohol moiety, silyl functions as large as TBDMS are accepted. The X‐ray crystal structure of SilE−R, determined to a resolution of 1.98 Å, in combination with mutational studies, revealed an active site featuring two histidine residues, H8 and H79, which likely act synergistically as nucleophile and Brønsted base in the hydrolytic mechanism, which has not previously been described for enzymes. Although the natural function of SilE−R and SilE−S is unknown, we propose that these ‘silyl etherases’ may have significant potential for synthetic applications.
Preparation and characterization of reprocessable poly(1,2,3‐triazolium)
Authors: Zhang Jun , Lv Shuaikang , Tang Junkun , Liu Zuozhen , Huang Farong 
Published: April 2024

AbstractPoly(1,2,3‐triazolium) (PTAM) is a dynamic reversible crosslinking polymer based on 1,2,3‐triazolium. Structural rearrangement of PTAM can occur through dynamic exchange reactions of 1,2,3‐triazolium. But there are not any applications derived from the dynamic reversible crosslinking properties of 1,2,3‐triazolium. In the paper, to expand the function and application of PTAM, a reprocessable PTAM resin has been prepared and the reprocess ability is studied in detail. PTAM can achieve complete stress relaxation within 2 min at 160°C through the exchange reaction of dynamically reversible crosslinked 1,2,3‐triazolium. Under the condition of 160°C and 10 MPa pressure, PTAM can achieve mechanical properties recovery after 2 h of reprocessing. The recovery rate of tensile strength can reach 94.2%. After four consecutive cycles reprocessing, the recovery rate of tensile strength is maintained at about 90%. And the thermal stability of PTAM is unchanged. PTAM has a possible application in the recycling of thermoset‐based plastics and composites. The result provides a reference for the functional application and development of dynamic reversible crosslinking polymers.
Whole‐body donation through the lens of Shona culture and Christian religion in Zimbabwe
Authors: Dongo Varaidzo , Chengetanai Samson , Chibhabha Fidelis 
Published: April 2024

AbstractVoluntary donation is the ethically acceptable method for whole‐body acquisition for anatomy education worldwide. In Africa, educational institutions struggle with this since many people remain unwilling to donate their bodies due to the strong influence of cultural and religious beliefs in decision‐making. As part of wider efforts to improve the ethical sourcing of bodies in Zimbabwean medical schools, which are heavily reliant on unclaimed bodies, this study sought to determine the influences traditional and religious beliefs have on such decisions. We ascertained traditional and religious leaders' knowledge of whole‐body donation, explored cultural and religious views toward death, dying and whole‐body donation as well as their underlying reasons. Semi‐structured interviews were conducted with traditional chiefs and Christian leaders who are considered the custodians of Zimbabwean traditional cultural and Christian values, respectively. Thematic analysis of traditional chiefs' interviews revealed that none of the chiefs had accurate knowledge regarding whole‐body donation or the processes involved. Due to set traditional practices around death, most traditional chiefs viewed the practice as foreign with possible negative repercussions to the dissectors. Most of the Christian leaders had knowledge of whole‐body donation. Their views were split between support for whole‐body donation and regard as a religious and cultural misfit. Overall, both traditional chiefs and Christian leaders understood the importance of whole‐body donation and requested further societal sensitization and education if the practice is to become socially acceptable.
Modelling on a Biomimetic [Cu−O−Cu]2+–mediated Methane–to–Methanol Conversion Unveils the Site for Methane Activation
Authors: Arora Sumangla , Gupta Puneet 
Published: April 2024

AbstractThe Cu−O−Cu core exhibits methane‐to‐methanol conversion, mirroring the reactivity of the copper–containing enzyme pMMO. Herein, we computationally examined the reactivity of a biomimetic Cu−O−Cu core towards methane–to–methanol conversion. The oxygen atom of the Cu−O−Cu core abstracts hydrogen present in the C−H bond of methane. The spin density at the bridging oxygen helps to abstract hydrogen from the C−H bond. We modulated the spin density of the bridging oxygen by substituting only a single copper atom of the Cu−O−Cu core by metals (M) such as Fe, Co, and Ag. These substitutions result in bimetallic [Cu−O−M]2+ models. We observed that the energy barriers for the C−H activation step and the subsequent rebound step vary with the metal M. [Cu−O−Ag]2+ exhibits the highest reactivity for M2M conversion, while [Cu−O−Fe]2+ displays the lowest reactivity. To understand the different reactivity of these models towards M2M conversion, we employed distortion‐interaction analysis, orbital analysis, spin density analysis, and quantum theory of atoms in molecules analysis. Orbital analysis reveals that all four adducts follow a hydrogen atom transfer mechanism for C−H activation. Further, spin density analysis reveals that a higher spin density on the bridging oxygen leads to a lower C−H activation barrier.
Current treatment and novel insights regarding ROS1‐targeted therapy in malignant tumors
Authors: Li Shizhe , Zhang He , Chen Ting , Zhang Xiaowen , Shang Guanning 
Published: April 2024

AbstractBackgroundThe proto‐oncogene ROS1 encodes an intrinsic type I membrane protein of the tyrosine kinase/insulin receptor family. ROS1 facilitates the progression of various malignancies via self‐mutations or rearrangements. Studies on ROS1‐directed tyrosine kinase inhibitors have been conducted, and some have been approved by the FDA for clinical use. However, the adverse effects and mechanisms of resistance associated with ROS1 inhibitors remain unknown. In addition, next‐generation ROS1 inhibitors, which have the advantage of treating central nervous system metastases and alleviating endogenous drug resistance, are still in the clinical trial stage.MethodIn this study, we searched relevant articles reporting the mechanism and clinical application of ROS1 in recent years; systematically reviewed the biological mechanisms, diagnostic methods, and research progress on ROS1 inhibitors; and provided perspectives for the future of ROS1‐targeted therapy.ResultsROS1 is most expressed in malignant tumours. Only a few ROS1 kinase inhibitors are currently approved for use in NSCLC, the efficacy of other TKIs for NSCLC and other malignancies has not been ascertained. There is no effective standard treatment for adverse events or resistance to ROS1‐targeted therapy. Next‐generation TKIs appear capable of overcoming resistance and delaying central nervous system metastasis, but with a greater incidence of adverse effects.ConclusionsFurther research on next‐generation TKIs regarding the localization of ROS1 and its fusion partners, binding sites for targeted drugs, and coadministration with other drugs is required. The correlation between TKIs and chemotherapy or immunotherapy in clinical practice requires further study.
Bioactives of Melipona rufiventris Propolis: Exploring its Antimicrobial, Anti‐Inflammatory, and Antioxidant Activities
Authors: Santini Amanda Tristão , Pinto Rayra Annara Otacílio , Lazarini Josy Goldoni , de Morais Daniel Vieira , de Piloto Fernandes Anna Maria Alves , Franchin Marcelo , de Carvalho Patrícia Lunardelli Negreiros , Pressete Carolina Girotto , Rosalen Pedro Luiz , de Alencar Severino Matias , de Oliveira Carvalho Patrícia , Ionta Marisa , Ikegaki Masaharu 
Published: April 2024

AbstractThis study explores the potential of propolis, a resinous substance produced by bees, from Melipona rufiventris species. With its composition encompassing resin, wax, pollen, and soil, propolis holds historical significance in traditional medicine within tropical regions. This research is driven by the scarcity of information surrounding M. rufiventris propolis, prompting an investigation into its chemical constituents, in vivo toxicity, and antimicrobial, antioxidant, and anti‐inflammatory properties. This exploration could potentially uncover novel applications for this natural product, bolstering both meliponiculture practices and the preservation of native bee populations. The propolis was sampled in Cabo Verde‐MG and underwent ethanolic extraction to yield an extract (EEP) for analysis. Chemical assessments (Folin‐Ciocalteau, and UHPLC‐HRMS) revealed the presence of polyphenols, including flavonoids. The EEP demonstrated higher antimicrobial activity against Gram‐positive bacteria and exhibited efficacy against multiresistant strains isolated from complex wounds. Synergistic interactions with commercial antibiotics were also observed. Furthermore, anti‐inflammatory evaluations showcased the EEP′s potential in reducing NF‐kB activation and TNF‐α release at non‐toxic concentrations. Despite these promising biological activities, the EEP exhibited no antiproliferative effects and demonstrated safety in both the MTS assay and the G. mellonella model. Collectively, these findings highlight the M. rufiventris propolis extract as a valuable reservoir of bioactive compounds with multifaceted potential.
Co‐Immobilization of ADH and GDH on Metal–Organic‐Framework: An Effective Biocatalyst for Asymmetric Reduction of Ketones
Authors: Ran Lu , Lin Yu , Su Guorong , Yang Zhenyan , Teng Huailong 
Published: April 2024

AbstractChiral alcohols are not only important building blocks of various bioactive natural compounds and pharmaceuticals, but can serve as synthetic precursors for other valuable organic chemicals, thus the synthesis of these products is of great importance. Bio‐catalysis represents one effective way to obtain these molecules, however, the weak stability and high cost of enzymes often hinder its broad application. In this work, we designed a biological nanoreactor by embedding alcohol dehydrogenase (ADH) and glucose dehydrogenase (GDH) in metal‐organic‐framework ZIF‐8. The biocatalyst ADH&GDH@ZIF‐8 could be applied to the asymmetric reduction of a series of ketones to give chiral alcohols in high yields (up to 99 %) and with excellent enantioselectivities (>99 %). In addition, the heterogeneous biocatalyst could be recycled and reused at least four times with slight activity decline. Moreover, E. coli containing ADH and GDH was immobilized by ZIF‐8 to form biocatalyst E. coli@ZIF‐8, which also exhibits good catalytic behaviours. Finally, the chiral alcohols are further converted to marketed drugs (R)‐Fendiline, (S)‐Rivastigmine and NPS R‐568 respectively.
Tuning the Microenvironment of Co−N4 Ensemble for Co Single‐Atom Catalysts for Electrocatalytic CO2 Reduction
Authors: Zeng Zizhen , Xu Junli , Zhao Yiran , Li Jiwei , Du Congcong , Sun Yifei , Xiong Haifeng 
Published: April 2024

AbstractSingle‐atom catalysts (SACs), with their well‐defined structure, serve as an efficient catalyst model for studying the structure‐performance relation in the electrocatalytic CO2 reduction reaction (CO2RR). Current CO2RR research primarily focus on the coordination interactions between metal single atoms and coordinated ligands, while the impact of the metal SAC′s microenvironment remains largely unexplored. Herein, we generate three microenvironments for a CoN4 ensemble by using different nitrogen sources to prepare Co SACs, i. e. pyridine‐type Co−N4 (Co−N4 SACPhen), the pyrrole‐type Co−N4 (Co−N4 SACDp) and the mixed‐type Co−N4(Co−N4 SACMm). It reveals that the Co−N4 SACPhen contributes to CO generation with 99.5 % selectivity at −0.76 vs RHE, whereas the Co−N4 SACDp accelerates a severe hydrogen evolution reaction. Experimental studies confirmed that the Co−N4 SACPhen possesses distinctive electrochemical properties and electronic structure, with the pyridine‐N being more conducive to electron accumulation and exhibited a higher electron delocalization, thereby promoting the generation of CO. This study deepens our understanding of the cobalt SAC′s microenvironment‘s influence on CO2RR.
Artificial Metalloenzyme‐Catalyzed Enantioselective Carboamination of Alkenes
Authors: Yu Kun , Tachibana Ryo , Rumo Corentin , Igareta Nico V. , Zhang Kailin , Ward Thomas R. 
Published: April 2024

AbstractRelying on ubiquitous alkenes, carboamination reactions enable the difunctionalization of the double bond by the concurrent formation of a C−N and a C−C single bond. In the past years, several groups have reported on elegant strategies for the carboamination of alkenes relying on homogeneous catalysts or enzymes. Herein, we report on an artificial metalloenzyme for the enantioselective carboamination of dihydrofuran. Genetic optimization, combined with a Bayesian optimization of catalytic performance, afforded the disubstituted tetrahydrofuran product in up to 22 TON and 85 % ee. X‐ray analysis of the evolved artificial carboaminase shed light on critical amino acid residues that affect catalytic performance.
Confined cobalt single‐atom catalysts with strong electronic metal‐support interactions based on a biomimetic self‐assembly strategy
Authors: Guo Bowen , Wang Zekun , Zheng Lei , Mo Guang , Zhou Hongjun , Luo Dan 
Published: April 2024

AbstractDesigning high‐performance and low‐cost electrocatalysts for oxygen evolution reaction (OER) is critical for the conversion and storage of sustainable energy technologies. Inspired by the biomineralization process, we utilized the phosphorylation sites of collagen molecules to combine with cobalt‐based mononuclear precursors at the molecular level and built a three‐dimensional (3D) porous hierarchical material through a bottom‐up biomimetic self‐assembly strategy to obtain single‐atom catalysts confined on carbonized biomimetic self‐assembled carriers (Co SACs/cBSC) after subsequent high‐temperature annealing. In this strategy, the biomolecule improved the anchoring efficiency of the metal precursor through precise functional groups; meanwhile, the binding‐then‐assembling strategy also effectively suppressed the nonspecific adsorption of metal ions, ultimately preventing atomic agglomeration and achieving strong electronic metal‐support interactions (EMSIs). Experimental characterizations confirm that binding forms between cobalt metal and carbonized self‐assembled substrate (Co–O4–P). Theoretical calculations disclose that the local environment changes significantly tailored the Co d‐band center, and optimized the binding energy of oxygenated intermediates and the energy barrier of oxygen release. As a result, the obtained Co SACs/cBSC catalyst can achieve remarkable OER activity and 24 h durability in 1 M KOH (η10 at 288 mV; Tafel slope of 44 mV dec−1), better than other transition metal‐based catalysts and commercial IrO2. Overall, we presented a self‐assembly strategy to prepare transition metal SACs with strong EMSIs, providing a new avenue for the preparation of efficient catalysts with fine atomic structures.
Biphase‐to‐monophase structure evolution of Na0.766+xLixNi0.33−xMn0.5Fe0.1Ti0.07O2 toward ultradurable Na‐ion batteries
Authors: Liu Mengting , Cheng Zhiwei , Zhu Xu , Dong Haojie , Yan Tianran , Zhang Liang , Zheng Lu , Yao Hu‐Rong , Wang Xian‐Zuo , Yu Lianzheng , Xiao Bing , Xiao Yao , Wang Peng‐Fei 
Published: April 2024

AbstractLayered composite oxide materials with O3/P2 biphasic crystallographic structure typically demonstrate a combination of high capacities of the O3 phase and high operation voltages of the P2 phase. However, their practical applications are seriously obstructed by difficulties in thermodynamic phase regulation, complicated electrochemical phase transition, and unsatisfactory cycling life. Herein, we propose an efficient structural evolution strategy from biphase to monophase of Na0.766+xLixNi0.33−xMn0.5Fe0.1Ti0.07O2 through Li+ substitution. The role of Li+ substitution not only simplifies the unfavorable phase transition by altering the local coordination of transition metal (TM) cations but also stabilizes the cathode–electrolyte interphase to prevent the degradation of TM cations during battery cycling. As a result, the thermodynamically robust O3‐Na0.826Li0.06Ni0.27Mn0.5Fe0.1Ti0.07O2 cathode delivers a high capacity of 139.4 mAh g−1 at 0.1 C and shows prolonged cycling life at high rates, with capacity retention of 81.6% at 5 C over 500 cycles. This work establishes a solid relationship between the thermodynamic structure evolution and electrochemistry of layered cathode materials, contributing to the development of long‐life sodium‐ion batteries.
Selective B(3)‐H Activation Affording Multinuclear Ir(III) Complexes with (o‐Carboranyl)dithioester Ligands
Authors: Zhu Yong‐Xiao , Yuan Run‐Ze , Zhang Hai‐Ning , Jin Guo‐Xin 
Published: April 2024

AbstractA method was developed to link two or three o‐carborane moieties to form a series of carboranyl dithioester bridging ligands via in situ substitution of haloalkanes by tetraphenylphosphonium carboranyldithiocarboxylates. Based on these ligands, direct B−H activation without the assistance of Ag(I) and alkali was successfully achieved with half‐sandwich Ir(III) substrate [Cp*IrCl2]2 to yield corresponding bimetallic or trimetallic complexes. Single crystal structure analyses of the B−H activated complexes and corresponding SnCl2‐inserted derivatives confirm the selective B(3)‐H activation in these complexes.
Opportunity of Patterning in Chemistry
Authors: Gentili Denis , Cavallini Massimiliano 
Published: April 2024

AbstractPatterning offers an efficient way to quantitatively enhance and enlarge material properties and functionalities, offering unprecedented opportunities for innovation in various scientific domains. By precisely controlling the spatial arrangement of materials at the micro‐ and nanoscale, patterning enables the exploitation of inherent material properties in novel ways. In addition, it generates new properties, leading to the development of advanced devices and applications. This article highlights the significant contributions of spatially controlled patterning in chemistry, particularly in generating new functional properties and devices, discussing some representative articles. Examples include the use of unconventional patterning techniques for surface functionalization, as well as the application of spatial confinement in improving material properties and controlling crystallization processes. Furthermore, the discussion extends to creating new devices, such as optical storage media and sensors, through spatial organization of materials.
Fluorescence and Lifetime Imaging of Endoplasmic Reticulum Polarity Change During Ferroptosis
Authors: Li Mingfeng , Chen Yuncong , He Weijiang , Guo Zijian 
Published: April 2024

AbstractAs a new form of regulated cell death, ferroptosis is closely related to various diseases. Tracing ferroptosis related biological behavior is helpful to better understand this process and its related biology. Considering that ferroptosis is featured with remarkable lipid peroxidation which can easily change the membranes’ compositions and structures, it is potential to detect intracellular environmental changes for direct assessment of ferroptosis. In view of the close relationship between endoplasmic reticulum (ER) and ferroptosis, we designed an ER‐targeted and polarity‐sensitive fluorescent probe SBD−CH, which has superior photostability and can respond to polarity with high selectivity without the affection of viscosity. SBD−CH can monitor the trend of ER polarity during ferroptosis by confocal laser scanning microscopy (CLSM), and analyze the distribution of polarity in ferroptosis by fluorescence lifetime imaging microscopy (FLIM). During Erastin induced ferroptosis, the polarity of ER in HT‐1080 cells increased and the polarity distribution in ER was more dispersed. Our work provides an effective strategy for evaluating the process of ferroptosis by monitoring the changes of ER polarity.