Chemical Science最新文献

{"title":"A combined experimental and computational study reveals a crossover between conventional cross-coupling and carbene insertion pathways in a Pd catalyzed C(sp2)–H insertion","authors":"Arushi Tyagi, Kritika Gaur, Anubhav Goswami, Arko Seal, Mayuk Joddar, Garima Jindal","doi":"10.1039/d5sc00777a","DOIUrl":"https://doi.org/10.1039/d5sc00777a","url":null,"abstract":"Computational (DFT and DLPNO-CCSD(T)) calculations along with experimental tools (deuterium labelling, kinetic studies using VTNA, ESI-HRMS and UV) are used to probe the mechanism of a Pd(<small>II</small>)-catalyzed enantioselective carbene insertion into C(sp<small>²</small>)–H of indole. Using deuterium labelling studies, we demonstrate the intermediacy of a metal-hydride species, which contrasts with mechanistic routes for other transition metals (Rh, Fe, Au, Cu, <em>etc.</em>). Our VTNA study reveals the order to be one in both diazo and indole, which along with microkinetic modelling aligns well with the computationally predicted mechanism. The mechanism is further supported by the detection of the most stable intermediate in the catalytic cycle using ESI-HRMS. An investigation into the origin of stereoselectivity using DLPNO-CCSD(T) presents a new paradigm, wherein stereocontrol arises during the formation of the Pd carbene itself as opposed to proton transfer steps found for all other metal catalysts.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"24 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Palladium/Norbornenes-Catalyzed C−H Bond Activation and Annulation to Construct Polycyclic Aromatic Hydrocarbons-based Fluorescent Materials","authors":"Chunlin Zhou, Xianhui Yang, Lian Gou, Bijin Li","doi":"10.1039/d5sc00617a","DOIUrl":"https://doi.org/10.1039/d5sc00617a","url":null,"abstract":"Reported herein is the first example of NBE-CO2Me-mediated palladium-catalyzed C−H bond activation and annulation of bromo(hetero)aromatics to construct structurally diverse polycyclic aromatic hydrocarbons (PAHs)-based fluorescent materials. The approach shows a broad substrate scope and provides straightforward access to screening high-performance fluorescent materials. Novel organic single-molecule white-light material with anti-Kasha dual-emission character has been developed herein. Furthermore, the anti-Kasha dual-emission material was fabricated as water-dispersed nanoparticles (NPs) to target the mitochondria of living cells. The corresponding NPs could be further applied in two-channel emission intensity ratio imaging to observe the cellular local imaging information and the intercellular structure.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"42 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular Engineering of 1D Conjugated Copper Anilate Coordination Polymers for Boosting Electrocatalytic Nitrate Reduction to Ammonia","authors":"Zhanning Liu, Chengyong Xing, Yufei Shan, Min Ma, Shaowen Wu, Ruixiang Ge, Qingzhong Xue, Jian Tian","doi":"10.1039/d4sc08508f","DOIUrl":"https://doi.org/10.1039/d4sc08508f","url":null,"abstract":"The electrochemical nitrate reduction reaction (NO3RR) offers a “two-birds-one-stone” solution by simultaneously addressing water pollution and enabling green ammonia production. However, its multiple reaction pathways and complex intermediates pose a challenge for designing high-efficient electrocatalysts. The highly modular nature of metal coordination polymers (MCPs), combined with molecular engineering strategies, provides a pathway for systematically exploring the structure-performance relationships of catalysts. As a proof of concept, we here synthesized a series of π-d conjugated copper anilate coordination polymers incorporating different halogen atoms (F, Cl and Br). The combined experimental and theoretical investigations reveal that introducing halogen atoms with electron-withdrawing properties can create an electron-deficient Cu center through the interchain Cu‧‧‧halogen supramolecular interactions, which can effectively lower the energy barrier for deoxygenation of *NO intermediate. As a result, the Cu-FA (FA = fluoranilate, C6O4F22-) achieves a superior NO3RR performance with the Faradic efficiency (FE) of 98.17% and yielding rate of 14.308 mg h-1 mg-1 at -0.9 V, nearly 7.7 times that of the pristine Cu-DABQ (DABQ = 2,5-dihydroxy-1,4-benzoquinone, C6O4H22-). This study may provide new insights into the design of high-performance NO3RR electrocatalysts.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"20 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Real-time visualization of epileptic seizures using photoacoustic imaging with a peroxynitrite-responsive manganese(II) texaphyrin","authors":"Yaguang Ren, Calvin V. Chau, Tao Chen, Jingqin Chen, Yu Hu, Zhonghua Lu, James T. Brewster, Jonathan F. Arambula, Rongkang Gao, Adam C. Sedgwick, Jonathan L. Sessler, Chengbo Liu","doi":"10.1039/d5sc00568j","DOIUrl":"https://doi.org/10.1039/d5sc00568j","url":null,"abstract":"Real-time visualization and tracking of epileptic seizures are important for studying epilepsy pathogenesis and treating epilepsy; however, the requisite sensing is extremely challenging, primarily due to the transient and intricate nature of neural activity associated with epilepsy. The onset of epilepsy is closely correlated with increases in peroxynitrite (ONOO<small>⁻</small>) levels, a reactive nitrogen species that can serve as a biomarker for epilepsy. However, the fleeting biological half-life and high reactivity of ONOO<small>⁻</small> has historically impeded its direct visualization within the epileptic brain. This study explores the efficacy of manganese(<small>II</small>) texaphyrin (MMn), a water-soluble and stable expanded porphyrin, in dynamically sensing ONOO<small>⁻</small> and providing real-time tracking of epileptic seizures using a custom-built photoacoustic imaging (PAI) setup. UV-vis spectral analyses established the preferential sensitivity of MMn to ONOO<small>⁻</small> over other reactive oxygen species (ROS), as well as its effectiveness through multiple usage cycles when rejuvenated <em>via</em> reaction with suitable reducing agents. This selectivity was recapitulated <em>in vitro</em> as determined through PAI experiments. <em>In vivo</em> application of this technique revealed that MMn administered intravenously crosses the blood–brain barrier (BBB) in a pentylenetetrazole (PTZ)-induced epilepsy mouse model and provides an observable 14.1 ± 3.7% reduction in photoacoustic (PA) signal intensity within the hippocampal region during epileptic seizures. Multiple decreasing–increasing cycles of PA signal intensity could be detected in the hippocampal region in this model; the observed effect thus mirrors closely the course of epileptic seizures inferred from mouse tail curling. Similar cyclical patterns were also seen in the motor cortex, a finding consistent with the extensive spread of epileptic activity throughout the brain. To the best of our knowledge, the present investigation represents the first real-time visualization and tracking of epileptic seizures using a peroxynitrite-specific sensing probe in combination with photoacoustic imaging (PAI). This approach enables deeper brain imaging while simultaneously capturing dynamic ONOO<small>⁻</small> fluctuations, offering biochemical insights into epilepsy pathogenesis. By integrating deep-tissue imaging with neurochemical monitoring, this method lays the foundation for potential advances in epilepsy management and treatment.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"33 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enantioselective Zn-Catalyzed Hydrophosphinylation of Nitrones: An Efficient Approach for Constructing Chiral α-Hydroxyamino-Phosphine Oxides","authors":"Jun Wang, Shihui Luo, Xinzhu Yuan, Jiangtao Cheng, Zhiping Yang, Zhongxing Huang","doi":"10.1039/d5sc01453k","DOIUrl":"https://doi.org/10.1039/d5sc01453k","url":null,"abstract":"Although enantioselective hydrofunctionalizations of nitrones are established for synthesis of various types of chiral hydroxylamines, the asymmetric catalytic hydrophosphinylation of nitrones remains highly challenging. Herein, an efficient asymmetric hydrophosphinylation of nitrones, catalyzed by the dinuclear zinc catalyst derived from ProPhenol, is presented, accommodating a variety of nitrones and phosphine oxides. This approach successfully addresses the long-standing challenge of catalytic hydrophosphinylation of C=N bond, and offers an efficient and rapid access towards chiral α-hydroxyamino-phosphine oxides. Control experiment suggests the oxide anion in the nitrone motif is crucial for the enantio-controlling.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"55 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Narrowband Multi-Resonance Pure-Red Emitters by Enhanced Molecular Orbitals Delocalization for High-Performance Organic Light-Emitting Diodes","authors":"Xiaowei Wang, Tao Hua, Nengquan Li, Guohao Chen, Zhanxiang Chen, Jingsheng Miao, Xiaosong Cao, Chuluo Yang","doi":"10.1039/d5sc01439e","DOIUrl":"https://doi.org/10.1039/d5sc01439e","url":null,"abstract":"Multiple resonance-induced thermally activated delayed fluorescence (MR-TADF) materials with pure-red gamut are demanded for high-definition organic light-emitting diodes (OLEDs) displays. To achieve efficient pure-red OLEDs with excellent color purity, we report three novel MR-TADF emitters: PhCzBN, PhBCzBN, and BCzBN, which integrate a dibenzo[c,g]carbazole segment into a para-boron/oxygen-embedded framework, resulting in the progressive extension of the molecular conjugation. This extension of the π-conjugated skeleton enhances frontier molecular orbitals (FMOs) delocalization and red-shifts the emission, yielding pure-red emission in toluene with satisfactory peak positions and narrow linewidths. The sensitized OLEDs incorporating PhCzBN, PhBCzBN, and BCzBN exhibit maximum external quantum efficiencies of 31.5%, 33.6%, and 33.8%, respectively. The current efficiencies of these devices reach as high as 42.5 cd A-1, which is higher than reported pure red emitters with comparable CIE coordinates. Notably, the devices based on BCzBN demonstrate an emission peak at 636 nm and superior CIE coordinates of (0.700, 0.300), closely aligning with the BT.2020 requirements for red gamut. This work presents a straightforward yet effective approach for developing high-performance pure-red MR-TADF OLEDs, marking a substantial advancement in wide-color gamut display technologies.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"55 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abiotic Formation of Hexoses and Disaccharides in Aqueous Microdroplets","authors":"Myles Edwards, Dylan Holden, R. Graham Cooks","doi":"10.1039/d4sc08402k","DOIUrl":"https://doi.org/10.1039/d4sc08402k","url":null,"abstract":"Understanding the chemical reactions that led to the origin of life is a fundamental challenge. The formose reaction, an abiotic pathway to monosaccharides, provides a mechanism of sugar formation from simple aldehydes and ketones. However, the reaction requires extreme pH, metal catalysts, and is prone to side reactions, leaving questions about how such processes could have occurred on a primitive Earth. The abiotic formation of more complex sugars, such as disaccharides also require catalysts, and remains underexplored compared to other classes of biomolecules. This study investigates the role of microdroplets in the formation of hexoses and their subsequent condensation reactions to produce disaccharides, without the need for catalysts. The microdroplet-mediated synthesis of fructose and sorbose from glyceraldehyde or dihydroxyacetone, as well as that of disaccharides from various pentoses or hexoses, was monitered via mass spectrometery. Products were confirmed by high resolution mass spectrometry and tandem mass spectrometry. The product distribution of glucose disaccharides was determined by matching the relative intensities of product ions to a mixture of six disaccharide and it showed a yield of 9.4% or 1.7μg/min/emitter . This study demonstrates the abiotic formation of disaccharides, such as xylobiose and maltose, provides a possible link between prebiotic sugar synthesis and extant carbohydrate biochemistry. Hexose formation and disaccharide synthesis are driven by the unique air water interface of microdroplets, where partial solvation, pH extremes, and fast mass transfer kinetics enable abiotic condensation.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"17 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic Proton Coupled Electron Transfer Quenching as Sensing Modality in Fluorescent Probes","authors":"Rasmus K. Jakobsen, Stine Grønfeldt Stenspil, Junsheng Chen, Bo W. Laursen","doi":"10.1039/d5sc00326a","DOIUrl":"https://doi.org/10.1039/d5sc00326a","url":null,"abstract":"Fluorescent off-on probes based on a modular design where an analyte sensitive PET moiety is attached to a fluorophore are extremely successful. Here we report a new modular fluorescence probe design switched by dynamic quenching due to proton coupled electron transfer (PCET) mediated by collision with weak bases in solution. The fluorescence lifetime of this probe directly report on the rate of deprotonation by the weak bases in the solution. We investigate the probe design, mechanism of response, and sensitivity to various abundant weak bases/metabolites including; acetate, glutamate, phosphate, valine, and amines. We find that this modular PCET based probe design, contrary to traditional PET probes, can work efficiently with a fluorescence lifetime readout providing a calibration free probe for weak bases. Upon further development we envision such dynamic PCET probes as sensitive tools for studies of cellular buffer systems and metabolite pools.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"69 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tandem Activated Caged Galactoside Prodrugs: Advancing Beyond Single Galactosidase Dependence","authors":"Yunying Tan, Jie Liu, Dianya Yong, Jing Hu, Peter Seeberger, Junjie Fu, Jian Yin","doi":"10.1039/d5sc00722d","DOIUrl":"https://doi.org/10.1039/d5sc00722d","url":null,"abstract":"β-Galactoside prodrugs, activated by β-galactosidase (β-gal) highly expressed in some cancer cells, have been explored as anticancer agents for three decades. However, the distribution of β-gal lacks sufficient specificity to ensure precise drug release at cancer sites. By utilizing the highly stringent substrate specificity of β-gal, we chose the naturally occurring hydroxyl group of galactose as a prodrug modification site and developed a new class of tandem activated caged galactoside (TACG) prodrugs that require an additional trigger for more controlled on-demand drug release. We demonstrated that attaching various masking groups to the 6-hydroxyl group of galactose renders the galactosides resistant to β-gal hydrolysis. Focusing on the photosensitive mask 4,5-dimethoxy-2-nitrobenzyl (DMNB), we synthesized O6-DMNB modified galactosides of combretastatin A4 and 8-hydroxyquinoline, showcasing their UV/β-gal-dependent anticancer activities. We further established synthetic routes for O2-, O3-, and O4-DMNB modified TACGs. Comparative intracellular studies highlighted the O2-DMNB modified TACG as the most effective positional isomer, offering superior light-dependent selectivity. This insight led to the discovery of O2-DMNB modified galactoside of combretastatin A4 as a potent UV-dependent microtubule assembly inhibitor. Our work provides a straightforward, effective, and universally applicable strategy for constructing dual-stimulus responsive galactoside prodrugs, extendable to various glycoside prodrugs, advancing carbohydrate-based drug discovery.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"6 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Squaramide-Based Ion Pair Receptors Can Facilitate Transmem-brane Transport of KCl and Zwitterions Including Highly Polar Amino Acids","authors":"Marta Zaleskaya-Hernik, Rayhanus Salam, Mario J González, Marcin Wilczek, Łukasz Dobrzycki, Nathalie Busschaert, Jan Romanski","doi":"10.1039/d5sc00866b","DOIUrl":"https://doi.org/10.1039/d5sc00866b","url":null,"abstract":"Misregulation of transmembrane ion transport in biological systems has been linked to a variety of diseases. As a result, supramolecular chemists have been trying to develop small molecules that facilitate the transmembrane transport of several ionic species. However, ion transport by small molecules is a passive process and needs to be overall charge neutral (i.e., when an ion is transported across a membrane, another ion needs to be transported as well to avoid charge separation). Ion pair receptors could therefore have great potential as transmembrane ion transporters because they can facilitate transport of an overall neutral species. Furthermore, ditopic ion pair receptors also have the potential to transport biologically important zwitterionic species, such as amino acids. In this manuscript, we report the synthesis of a series of ditopic receptors based on squaramides as the anion binding unit and 18-crown-6 as the cation binding unit. UV-Vis and NMR titrations revealed that these compounds can bind a variety of chloride salts, especially KCl. Furthermore, liquid-liquid extractions and transport experiments using bulk liquid membranes and liposomes indicate that these ditopic receptors are capable of transporting chloride salts and hydrophilic amino acids. In fact, compound 5 was even able to facilitate the transport of amino acids with charged side chains at physiological pH (arginine and glutamate), making it the first example of a small molecule that can transport these highly polar and charge-dense species. These findings open up the possibility of using these receptors in a wide range of biological applications.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"40 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}