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Synergistic silver-mediated and palladium-catalyzed nondirected olefination of aryl C–H bond: quick access to multi-substituted aryl olefins

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Science China chemistry 2024年第3期67卷 882-889页

作者： Jian Yao Lili Shao Xiaohong Huo Xiaoming Wang Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs Frontiers Science Center for Transformative MoleculesSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Organometallic chemistry Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 20032China School of chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China

Transition metal-catalyzed olefination of aryl C-H bond is a powerful tool for the synthesis of alkenes. While the Pd-catalyzed oxidative C-H olefination of arenes, also known as Fujiwara-Moritani reaction, has been established as one of the most efficient methods, the substrates are largely limited to terminal olefins with electron-withdrawing group(s). Herein, we report a synergistic silver-mediated and palladium-catalyzed non-directed C-H olefination of arenes with vinyl(pseudo)halides, which offers a complementary strategy to the typical Fujiwara-Moritani reaction. The reactions proceeded well for a variety of halogenated arenes, heteroarenes, and olefin substrates, providing an efficient access to various multi-substituted aryl olefins, including trisubstituted/tetrasubstituted olefins and several complex olefins derived from medicines or natural products. Mechanistic studies indicated a bimetallic Pd/Ag cooperation is operative in the catalysis, i.e., the reaction is initiated by aryl C-H bond cleavage via ligation with phosphine/Ag species, followed by transferring of the aryl moiety to a vinyl palladium intermediate,which is in turn formed by oxidative addition of vinyl(pseudo)halide to a Pd complex. This method enables the synthesis of a wide range of challenging multi-substituted vinyl products from simple arenes(directing-group free) in a streamlined and controllable fashion.

关键词： direct C–H olefination multi-substituted aryl alkenes bimetallic Pd/Ag cooperation C–H functionalization

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Visible-Light-Promoted Palladium-Catalyzed Cross-Coupling of lodocarboranes with Disulfides and Phenylselenyl Chloride

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Chinese Journal of chemistry 2024年第2期42卷 129-134页

作者： Shimeng Li Yizhen Liu Zuowei Xie Shenzhen Grubbs institute and Department of chemistry Southern University of Science and TechnologyShenzhenGuangdong 518055China

This work describes a general method for the synthesis of a series of sulfenylated and selenylated carboranes at room temperature using readily available iodocarboranes as starting materials via boron-centered carboranyl *** hypervalent boron radicals are generated by a visible-light-promoted Pd(O)/Pd(I)*** are useful intermediates and can be trapped by disulfides and phenylselenyl chloride for the convenient construction of B-S/Sebonds.

关键词： Carborane Sulfenylation Selenylation B-I activation Radical Photocatalysis Boron Selectivity

Local environment regulation of transition metal dichalcogenide-based single-atom catalysts

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Rare Metals 2024年第9期43卷 4019-4037页

作者： Ming-Hui Li Jing Li Xiao-Yu Zheng Yao Zhou Advanced Research institute of Multidisciplinary Science andSchool of chemistry and Chemical Engineering Beijing Institute of Technology Laser Micro/Nano Fabrication Laboratory School of Mechanical Engineering Beijing Institute of Technology

Single-atom catalysts have risen significant attention in the realm of green electrocatalytic energy conversion to address energy and environmental sustainability challenges. Transition metal dichalcogenide（TMD）-based single-atom catalysts are considered highly effective in electrocatalysis due to the TMDs' notable specific surface area, tunable elemental species and efficient utilization of single atoms. In order to enhance electrocatalytic performance, it is imperative to elaborately engineer the local environment surrounding the active sites of single atoms within TMDs. In this review, we initially explore the effects of synthesis methods on single-atom active sites and the influence of loading of single atoms on catalytic performance for TMDs. The modulation strategies of the local environment surrounding single-atom sites in TMDs are elaborated, including substitution engineering,surface adsorption, vacancies, spatial confinement and dual-atom site strategies. For each modulation strategy, the effects of diverse local environments on various electrocatalytic applications are presented, such as the oxygen evolution reaction, oxygen reduction reaction, nitrogen reduction reaction, CO2reduction reaction and CO oxidation. Ultimately, this study presents a comprehensive overview of the challenges encountered and the potential directions for the advancement of single-atom catalysts based on TMDs in the realm of electrocatalysis.

关键词： Electrocatalysis

Polyhydroxyurethanes from Biobased Monomers and CO_(2):A Bridge between Sustainable chemistry and CO_(2) Utilization

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Chinese Journal of chemistry 2024年第6期42卷 652-685页

作者： Tharinee Theerathanagorn Tanika Kessaratikoon Hafeez Ur Rehman Valerio D'Elia Daniel Crespy VISTEC Advanced Laboratory for Environment-Related inorganic and Organic Syntheses Department of Materials Science and EngineeringVidyasirimedhi Institute of Science and Technology21210Wang ChanRayongThailand Department of Materials Science and Engineering Vidyasirimedhi Institute of Science and Technology21210Wang ChanRayongThailand

Polyhydroxyurethanes(PHUs)have received considerable attention in the last decade as potential alternatives to traditional phosgene-based polyurethanes(PUs).The development of suitable 5CC(five membered-ring cyclic carbonate)precursors bearing multiple carbonate moieties(multi-5CCs)is a key requisite for preparing PHUs by polyaddition reaction with bis-or *** sustainable PHUs from CO_(2)-based five-membered cyclic carbonates(5CCs)obtained from biobased epoxides is a valuable strategy to bridge CO_(2) utilization and the upcycling of renewable *** this context,while many multi-5CC monomers reported in the literature are oil-based,recent efforts have led to the development of a large variety of multifunctional 5CCs that are produced by the combination of CO_(2) and renewable resources such as fatty acids and vegetable oils,lignin,terpenes,and *** this work,recent crucial advances(2019—2023)on PHUs prepared from bis-and multi-5CCs produced from CO_(2) and(partially/potentially)biobased substrates are reviewed with respect to their synthesis,thermal and mechanical properties,and their recent,emerging applications.

关键词： CO_(2) conversion Polyhydroxyurethanes Cyclic carbonates Biobased compounds Fatty acids Functional polymers Monomers Renewable resources

[H_(2)dab][GaB_(5)O_(10)]:an Acentric Galloborate with a 4-Connected Uninodal Framework

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Chemical Research in Chinese Universities 2024年第4期40卷 747-752页

作者： LIU Wenfang CHEN Chongan YANG Guoyu School of chemistry and Chemical Engineering Beijing Institute of TechnologyBeijing102488P.R.China

A new acentric galloborate(GBO)[H_(2)dab][GaB_(5)O_(10)](1,1,4-dab:1,4-diaminobutane)has been synthesized under solvothermal *** alternation of 4,4-connected GaO4 and B5O10 cluster build up the 3D[GaB_(5)O_(10)]_(n)^(2n-)uninodal framework,which contains three pairs of helical channels with 8-member ring(MR)and 7-MR apertures,*** 1 exhibits a moderate second harmonic generation(SHG)response of 1.8 times that of KH_(2)PO_(4)(KDP),indicating its potential application in UV *** acentric uninodal framework in compound 1 represents a new type of zeolitic framework in the GBOs’family.

关键词： Galloborate Solvothermal synthesis Nonlinear optics Zeolitic framework

Heterocatalytic ethylene methoxycarbonylation via a pseudo-hydride pathway over Pt_(1)/MoS_(2)

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Science China chemistry 2024年第8期67卷 2427-2428页

作者： Bo-Hang Zhao Bin Zhang institute of Molecular Plus Department of ChemistrySchool of ScienceTianjin UniversityTianjin 300072China

Ethylene (C2H4) methoxycarbonylation (EMC) with CO and methanol (CH3OH) to methyl propanoate (MP) is industrially important due to its 100% atom efficiency [1].However, the heavy reliance on homogeneous Pd-based catalysts and strong acid media over commercial EMC processes still causes economic and environmental concerns [2]. At present, supported single-atom catalysts (SACs) can serve as bridges for accessing homogeneous catalysts in traditional heterogeneous catalytic processes.

关键词： processes. catalytic hydride

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Single-atom Pt on carbon nanotubes for selective electrocatalysis

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Carbon Energy 2024年第1期6卷 63-71页

作者： Samuel S.Hardisty Xiaoqian Lin Anthony R.J.Kucernak David Zitoun Department of chemistry Bar Ilan Institute of Nanotechnology and Advanced Materials(BINA)Bar Ilan UniversityRamat GanIsrael Department of chemistry Molecular Science Research HubImperial College LondonLondonUK

Utilizing supported single atoms as catalysts presents an opportunity to reduce the usage of critical raw materials such as platinum,which are essential for electrochemical reactions such as hydrogen oxidation reaction(HOR).Herein,we describe the synthesis of a Pt single electrocatalyst inside single-walled carbon nanotubes(SWCNTs)via a redox *** via electron microscopy,X-ray photoelectron microscopy,and X-ray absorption spectroscopy show the single-atom nature of the *** electrochemical behavior of the sample to hydrogen and oxygen was investigated using the advanced floating electrode technique,which minimizes mass transport limitations and gives a thorough insight into the activity of the *** single-atom samples showed higher HOR activity than state-of-the-art 30%Pt/C while almost no oxygen reduction reaction activity in the proton exchange membrane fuel cell operating *** selective activity toward HOR arose as the main fingerprint of the catalyst confinement in the SWCNTs.

关键词： confinement electrocatalysis hydrogen platinum single atom catalysts

Differentially-grown cobalt regulators cooperatively involved in the tandem catalysis for high-yield production of second amines

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Nano Research 2024年第4期17卷 2444-2450页

作者： Jinhui Xu Xiao Wang Ying Wang Fei Wang Lingling Zhang Wenjie Cui Shuyan Song Hongjie Zhang State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied chemistry and Engineering University of Science and Technology of ChinaHefei 230026China Department of chemistry Tsinghua UniversityBeijing 100084China

One-pot tandem catalysis has been regarded as one of the most atomic economic ways to produce secondary amines,the important platform molecules for chemical synthesis and pharmaceutical manufacture,but it is facing serious issues in overall *** promotional effects are highly desired for boosting the activity and regulating the selectivity of conventional tandem *** this work,we report a high-performance tandem catalyst with maximized synergistic effect among each counterpart by preciously manipulating the spatial structure,which involves the active CeO_(2)/Pt component as kernel,the densely-coated N-doped C(NC)layer as selectivity controller,and the differentially-grown Co species as catalytic performance *** comprehensive investigations,the unique growth mechanism and the promotion effect of Co regulators are ***,the surface-landed Co clusters(Cocs)are crucial to selectivity by altering the adsorption configuration of benzylideneaniline ***,the inner Co particles(Cops)are essential for activity by denoting their electrons to neighboring *** from the unique promotion effect,a remarkably-improved catalytic efficiency(100%nitrobenzene conversion with 94%N-benzylaniline selectivity)is achieved at a relatively low temperature of 80℃,which is much better than that of CeO_(2)/Pt(100%nitrobenzene conversion with 12%N-benzylaniline selectivity)and CeO_(2)/Pt/NC(35%nitrobenzene conversion with 94%benzylideneaniline selectivity).

关键词： tandem catalysis CeO_(2) hierarchical structure heterogeneous catalyst dual-site materials

Injectable chitosan hydrogels loaded with antioxidant agent as first-aid dressings for second-degree burn wounds

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Science China(Technological Sciences) 2024年第3期67卷 891-901页

作者： REN Hui ZHANG Zhen LU KaiLun SHEN YuanYuan HE ChaoLiang CHEN XueSi CAS Key Laboratoryof Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Burn wounds are destructive skin traumas typically of irregular shape and large area. Prone to infection, they require frequent dressing replacement, and painless removal of dressings from burn wounds remains a major challenge. This study focuses on the dynamic characteristics and treatment difficulty of burn wounds. Hydrogel dressings based on glycol chitosan and propionaldehyde-or benzaldehyde-terminated 4-arm poly(ethylene glycol) were designed on the basis of Schiff base cross-linking networks. The hydrogels exhibited shape-adaptability, self-healing and fast-degradation properties, which makes these hydrogels suitable for burn wounds. Salvianolic acid B(SaB)-loaded hydrogel exhibited good antioxidant properties in vitro. In a rat model of deep second-degree burn wounds, the SaB-loaded hydrogel could quickly reduce wound temperature, regulate wound oxidant microenvironment, promote angiogenesis, and accelerate wound healing. Thus, the drug-loaded hydrogel shows significant potential as a first-aid dressing for treatment of burn wounds.

关键词： hydrogel dressing fast-degradation shape-adaptability stress relaxation burn wound treatment

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