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C_(Ar)-Br bond cleavage via cooperative EnT/NHC catalysis: mild access to indolines

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Science China Chemistry 2024年第3期67卷 922-927页

作者： Yi-Xiong Dong Cao-Bo Li Ming-Lei Jin Zhong-Hua Gao Song Ye Beijing National Laboratory for molecular Sciences CAS Key Laboratory of Molecular Recognition and FunctionCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

The cooperative visible-light mediated and NHC-catalyzed dearomative arylation-acylation of N-(2-bromobenzoyl)indoles with aldehydes was developed, affording the corresponding highly functionalized polycyclic indolines in moderate to good yields with exclusive diastereoselectivities. Mechanism investigations support the activation of CAr-Br bond via visible-light mediated energy transfer(EnT) and the following single-electron-transfer(SET) with Breslow intermediate under NHC catalysis to give key aryl radical and ketyl radical. This protocol demonstrates the cleavage of CAr-Br bond under mild cooperative EnT/NHC catalysis.

关键词： energy transfer N-heterocyclic carbenes photocatalysis aryl radicals indolines

An unprecedented synthesis of axially chiral biaryls by rearrangement and aromatization of carbocations with central-to-axial conversion of chirality

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Science China Chemistry 2024年第9期67卷 2998-3003页

作者： Qi Liu Xue-Dong Li Liang Cheng Li Liu Beijing National Laboratory for molecular Sciences(BNLMS) CAS Key Laboratory of Molecular Recognition and FunctionCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

The central-to-axial chirality conversion represents a fascinating class of chemical processes consisting of the destruction of stereogenic centers and the simultaneous installation of axial chiral elements,which provides efficient methods for the preparation of axially chiral ***,developing catalytic asymmetric approaches for constructing these central chirality precursors and the efficient central-to-axial chirality conversion remains a challenge due to the requirement of aromatization or elimination *** this work,we have developed an unprecedented enantioselective intramolecular FriedelCrafts alkylation with unactivated-ketone carbonyls from which a chiral tertiary alcohol was generated with high efficiency and excellent *** addition,the central-to-axial chirality conversion strategy has been successfully applied to the synthesis of enantioenriched biaryls via a less-explored carbocation-initiated rearrangement and aromatization under the promotion of Lewis *** methodology provided a straightforward and sustainable access to a broad range of biaryl-2-carboxylic acid and in excellent yields(up to 92%)and excellent central-to-axial chirality conversion(up to 99%conversion percentage).This work could be a great model for developing new methods for synthesizing axially chiral biaryls and a general protocol for the rearrangement and aromatization of carbocations for further functionalization.

关键词： br?nsted acid catalysis desymmetrization phosphoric acid axially chiral biaryls central-to-axial conversion

Rational Design of Capping Ligands of Quantum Dots for Biosensing

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Chemical research in Chinese Universities 2024年第2期40卷 162-172页

作者： XU Xinran LIU An-an PANG Daiwen State Key Laboratory of Medicinal Chemical Biology Tianjin Key Laboratory of Biosensing and Molecular RecognitionResearch Center for Analytical SciencesCollege of ChemistryNankai UniversityTianjin300071P.R.China

Quantum dots have been widely applied in biosensing due to their outstanding optical *** emissions of quantum dots are mainly determined by their composition and size,as described by the Brus’s ***,in this case,their emissions are hardly regulated reversibly and responsively,which are unsuitable for biosensing and *** the last decade,capping ligands have been used for designing biosensors because of their responsive regulation on the photoluminescence of quantum ***,we first summarize the advances in characterization and calculation specific for ligands,which have helped to provide insights into the photoluminescence process and energy band theory of quantum *** then review two ways of ligand design that influence the optical properties of quantum dots:affecting the process of photoluminescence,or the orbital/electronic *** the latter case,the atoms on both the ligand and the surface of the quantum dot interact to affect the energy band structure of the quantum dot *** are presented of how these quantum dots that possess responsive properties due to the design of the ligands have been applied to *** further exploration,we hope to see advances in the fundamental understanding of the energy band structures and practical applications of these quantum dots.

关键词： Quantum dot Ligand Photoluminescence Responsiveness Sensor

Cr-catalyzed allylic C(sp^(3))–H addition to aldehydes enabled by photoinduced ligand-to-metal charge transfer

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Science China Chemistry 2024年第5期67卷 1589-1595页

作者： Xianrong Zeng Feng-Hua Zhang Runchen Lai Xiaoyu Lin Zhaobin Wang Key Laboratory of Precise synthesis of Functional Molecules of Zhejiang Province Department of ChemistrySchool of Science and Research Center for Industries of the FutureWestlake UniversityHangzhou 310030China Institute of Natural Sciences Westlake Institute for Advanced StudyHangzhou 310024China Key Laboratory of Precise synthesis of Functional Molecules of Zhejiang Province Instrumentation and Service Center for Molecular SciencesWestlake UniversityHangzhou 310024China

Photoinduced ligand-to-metal charge transfer(LMCT) has emerged as an effective strategy for synthesizing organic molecules in a sustainable manner. However, the majority of existing reports on selective C(sp^(3))–H bond functionalization via photoinduced LMCT focus on the use of late transition metals or rare-earth metals for radical additions or cross-couplings. In contrast, the utilization of photoinduced LMCT with 3d early transition metals poses a significant challenge. Herein, we describe an unprecedented approach to allylic C(sp^(3))–H addition to aldehydes, employing chromium(Cr) complexes as catalysts through visible-light-induced LMCT. By investigating the reaction pathway through various mechanistic studies, including radical trapping, kinetic isotope effect(KIE) analysis, and transient absorption spectroscopy, valuable insights have been gained. The proposed mechanism suggests the intermediacy of bromine radicals through homolysis of the Cr–Br bond. Notably, this protocol expands our understanding of the photochemical properties of earth-abundant Cr complexes.

关键词： Cr catalysis photoinduced ligand-to-metal charge transfer hydrogen-atom transfer carbonyl addition

Intracellular redox potential-driven live-cell synthesis of CdSe quantum dots in Staphylococcus aureus

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Science China Chemistry 2024年第3期67卷 990-999页

作者： Cai-Qin Wu An-An Liu Xu Li Jia-Wei Tu Juan Kong Ling-Ling Yang Jian-Hong Jia Chuan Wang Bin Hu Zhi-Xiong Xie Dai-Wen Pang The Institute for Advanced Studies College of Chemistry and Molecular SciencesCollege of Life SciencesHubei Key Laboratory of Cell HomeostasisWuhan UniversityWuhan 430072China research center for Analytical Sciences College of ChemistryState Key Laboratory of Medicinal Chemical BiologyTianjin Key Laboratory of Biosensing and Molecular RecognitionFrontiers Science Center for New Organic MatterFrontiers Science Center for Cell Responsesand Haihe Laboratory of Sustainable Chemical TransformationsNankai UniversityTianjin 300071China

Biosynthesized semiconductor quantum dots(QDs) have bright fluorescence,adjustable particle sizes,and environmental friendliness,endowing them with convenience and potential for biological *** to the unclear mechanism of the cellular environment on the live-cell synthesis of QDs,it is still difficult to regulate their optical ***,the critical role of the intracellular redox environment in regulating the fluorescence properties of biosynthesized CdSe QDs in Staphylococcus aureus(***) has been *** glutathione peroxidase(GPx) activity directly affects the intracellular H_(2)O_(2) produced in the SeO_(3)^(2-) reduction,which further manipulates the glutathione redox cycle to determine the content of low-valence *** a result,the fluorescence intensity of the synthesized CdSe QDs increases by 60% in the GPx overexpressed *** cellular redox potential that is controlled by the GSH redox cycle provides the driving force for the reduction of SeO_(3)^(2-),facilitating the synthesis of CdSe QDs in *** *** proposed mechanism of the cellular redox state provides a new perspective for regulating the synthesis of semiconductor nanomaterials in live cells.

关键词： redox H_(2)O_(2) peroxidase quantum dot Staphylococcus aureus

Genome editing of PAR2 through targeted delivery of CRISPR-Cas9 system for alleviating acute lung inflammation via ERK/NLRP3/IL-1β and NO/iNOS signalling

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Acta Pharmaceutica Sinica B 2024年第3期14卷 1441-1456页

作者： Xin Zhuo Yue Wu Xiujuan Fu Jianbin Li Yuxin Xiang Xiaoyu Liang Canquan Mao Yuhong Jiang Sichuan Engineering research center for Biomimetic synthesis of Natural Drugs School of Life Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China

Excessive and uncontrollable inflammatory responses in alveoli can dramatically exacerbate pulmonary disease progressions through vigorous cytokine releases,immune cell infiltration and protease-driven tissue *** is an urgent need to explore potential drug strategies for mitigating lung ***-activated receptor 2(PAR2)as a vital molecular target principally participates in various inflammatory diseases via intracellular signal ***,it has been rarely reported about the role of PAR2 in lung *** study applied CRISPR-Cas9 system encoding Cas9 and sg RNA(p Cas9-PAR2)for PAR2 knockout and fabricated an anionic human serum albuminbased nanoparticles to deliver p Cas9-PAR2 with superior inflammation-targeting efficiency and stability(TAP/p Cas9-PAR2).TAP/p Cas9-PAR2 robustly facilitated p Cas9-PAR2 to enter and transfect inflammatory cells,eliciting precise gene editing of PAR2 in vitro and in ***,PAR2 deficiency by TAP/p Cas9-PAR2 effectively and safely promoted macrophage polarization,suppressed proinflammatory cytokine releases and alleviated acute lung inflammation,uncovering a novel value of *** also revealed that PAR2-mediated pulmonary inflammation prevented by TAP/p Cas9-PAR2was mainly dependent on ERK-mediated NLRP3/IL-1β and NO/i NOS ***,this work indicated PAR2 as a novel target for lung inflammation and provided a potential nanodrug strategy for PAR2 deficiency in treating inflammatory diseases.

关键词： Protease-activated receptor 2(PAR2) CRISPR-Cas9 Gene editing Inflammation Acute lung inflammation NLRP3 Nanoparticles Drug delivery

Phenotype-Directed DNA Nanomachine for in Situ Analysis of Stem Cell-like Subpopulation in Breast Cancer

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CCS Chemistry 2024年第4期6卷 1034-1046页

作者： Ya Cao Huiru Mao Lingjun Sha Qi Liu Bing Han Jing Zhao Genxi Li center for molecular recognition and Biosensing Shanghai Engineering Research Center of Organ RepairSchool of Life SciencesShanghai UniversityShanghai 200444 State Key Laboratory of Analytical Chemistry for Life Science School of Life SciencesNanjing UniversityNanjing 210023

The cancer stem cell hypothesis provides a basis for prediction of the recurrence and risk of metastasis in breast ***,the unique expression pattern of stemness markers and the presence of nonstem-like cancer cells with varied phenotypes have brought great challenges to the characterization of breast cancer stem *** address these challenges,a phenotype-directed DNA nanomachine has been designed for high-accuracy labeling and in situ analysis of the stem cell-like subpopulation in breast *** key for the design is to use cell surfaceanchored inputs to activate the nanomachine,which undergoes different branch migration pathways such that the signal strand can only be brought onto the cancer cells having the stem cell-like *** sensitive determination and single-step isolation of the stem cell-like subpopulation were achieved by incorporating functional groups into the signal strand such that the nanomachine was successfully applied in a tumor-bearing mouse ***,the approach provides for a substantial improvement in capability for the analysis of the breast cancer stem cell-like subpopulation,and it is expected that the new approach will advance the use of DNA nanomachines in cancer-related studies.

关键词： breast cancer DNA nanomachine stem cell-like subpopulation electrochemical determination single-step isolation phenotypic analysis

A flame-retardant binder with high polysulfide affinity for safe and stable lithium–sulfur batteries

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Science China Chemistry 2024年第3期67卷 1028-1036页

作者： Guowei Yu Guofeng Ye Cheng Wang Chenyang Wang Zhaoyun Wang Pu Hu Yu Li Xi-Xi Feng Shuang-Jie Tan Min Yan Sen Xin Zhitian Liu Hubei Key Laboratory of Plasma Chemistry and Advanced Materials Hubei Engineering Technology Research Center of Optoelectronic and New Energy MaterialsSchool of Materials Science and EngineeringWuhan Institute of TechnologyWuhan 430205China State Key Laboratory of Advanced Technology for Materials synthesis and Processing Wuhan University of TechnologyWuhan 430070China CAS Key Laboratory of molecular Nanostructure and Nanotechnology CAS Research/Education Center for Excellence in Molecular SciencesBeijing National Laboratory for Molecular Sciences(BNLMS)Institute of ChemistryChinese Academy of Sciences(CAS)Beijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Lithium-sulfur(Li-S) batteries have shown promises for the next-generation, high-energy electrochemical storage, yet are hindered by rapid performance decay due to the polysulfide shuttle in the cathode and safety concerns about potential thermal runaway. To address the above challenges, herein, we show a flame-retardant cathode binder that simultaneously improves the electrochemical stability and safety of batteries. The combination of soft and hard segments in the polymer framework of binders allows high flexibility and mechanical strength for adapting to the drastic volume change during the Li(de)intercalation of the S cathode. The binder contains a large number of polar groups, which show the high affinity to polysulfides so that they help to anchor active S species at the cathode. These polar groups also help to regulate and facilitate the Li-ion transport, promoting the kinetics of polysulfide conversion reaction. The binder contains abundant phosphine oxide groups, which, in the case of battery's thermal runaway, decompose and release PO· radicals to quench the combustion reactions and stop the fire. Consequently, Li-S batteries using the new cathode binder show the improved electrochemical performance, including a low-capacity decay of 0.046% per cycle for 800 cycles at 1 C and favorable rate capabilities of up to 3 C. This work offers new insights on the practical realization of high-energy rechargeable batteries with stable storage electrochemistry and high safety.

关键词： lithium–sulfur battery polymer binder polysulfide affinity flame retardancy

Advances of graphdiyne-supported metal catalysts in thermocatalytic reactions

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Nano research 2024年第4期17卷 2223-2233页

作者： Jia Yu Yida Yang Yuliang Li Changyan Cao Weiguo Song Beijing National Laboratory for molecular Sciences CAS Research/Education Center for Excellence in Molecular SciencesLaboratory of Molecular Nanostructures and NanotechnologyInstitute of ChemistryChinese Academy of SciencesBeijing 100190China School of Chemical Sciences University of Chinese Academy of SciencesBeijing 100049China Beijing National Laboratory for molecular Sciences CAS Research/Education Center for Excellence in Molecular SciencesLaboratory of organic solidsInstitute of ChemistryChinese Academy of SciencesBeijing 100190China

Supported metal catalysts are widely used in the modern chemical *** electronic interaction between supports and active components is of great significance for heterogeneous ***(GDY),a new type of carbon allotrope with sp-hybridized carbon atoms,πconjugate structure,and electron transmission capability,is a promising candidate as catalyst *** years have witnessed the rapid progress of GDY-supported metal catalysts for different catalysis *** that most processes in the current chemical industry are thermocatalytic reactions,we herein give an overview about the advances and particular characteristics of GDY-supported catalysts in these *** geometric structure and electronic properties of GDY are first ***,the synthesis methods for GDY-supported metal catalysts and their applications in thermocatalytic reactions are discussed,in which the effect of electronic interaction on catalytic performance is ***,the current challenges and future directions of GDY-supported metal catalysts for thermocatalysis are *** is expected that this review will enrich our understanding of the advances of GDY as a superior support for metal catalysts in thermocatalytic reactions.

关键词： graphdiyne metal catalysts thermocatalytic reactions heterogeneous catalysis