检索结果-南通市图书馆

dft study on dinuclear palladium complexes catalyzing pyrrole formation from tert-butylisocyanide and alkynes

在线全文

学校读者我要写书评

暂无评论

DFT Study on dinuclear palladium complexes catalyzing pyrrol...

Synthesis of medium-sized benzo[b]azocines and benzo[b]azonines by photoinduced 8-/9-endo sulfonyl-cyclization

中国化学会第十六届全国均相催化学术会议

作者：赖晓玲 Yang Li 大连理工大学 Dalian University of Technology

The dipalladium complexes bridged by binucleating ligands were successfully synthesized by Naofumi Tsukada’s group and they performed some experiments about the application of the complexes to a pyrrole forming reaction in 2009. The detailed reaction mechanism for pyrrole formation from tert-butylisocyanide and various alkynes catalyzed by the dinuclear palladium complex ([Pd(t-Bu NC)(l-dpfam)]) (a) having two isocyanide ligands has been studied with the aid of density functional theory (dft) calculations.

关键词： dipalladium complex catalysis mechanism regioselectivity dft study

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Science China Chemistry 2023年第8期66卷 2309-2316页

作者： Kai Sun Dongyang Zhao Quanxin Li Shaofei Ni Guangfan Zheng Qian Zhang College of Chemistry and Chemical Engineering Yantai UniversityYantai264005China College Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province Shantou UniversityShantou515063China Department of Chemistry Northeast Normal UniversityChangchun130024China

An efficient photochemical radical sulfonyl cyclization of designed dienes to medium-sized benzo[b]azocines and benzo[b]azonines was *** chemoselective method provides new highly functionalized eight-and nine-membered *** inhibition experiments,light on/off experiments,and apparent quantum efficiency calculations were used to clarify the radical *** functional theory calculations enabled rationalization of the rate-determining step and observed ***-scale synthesis and derivatizations via epoxidation and convenient N-Ts deprotection showed the potential utility of this *** photochemical method for synthesizing sulfonylbenzo[b]azocines and sulfonylbenzo[b]azonines with insertion of sulfur dioxide provides new sustainable routes for the synthesis of valuable medium-sized Nheterocycles.

关键词： photocatalysis medium-sized N-heterocycles radical cascade cyclization dft study

同方期刊数据库

Insight into the CO2 photoreduction mechanism over 9-hydroxyphenal-1-one(HPHN) carbon quantum dots

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2021年第1期30卷 269-276,I0009页

作者： Zhengyan Zhao Heming Zhang Xuedan Song Yantao Shi Duanhui Si Hongjiang Li Ce Hao State Key Laboratory of Fine Chemicals School of Chemical EngineeringDalian University of TechnologyDalian 116024LiaoningChina

Converting CO2 to carbon-containing fuels is an effective approach to relieving energy *** quantum dots(CQDs) have shown distinct properties and attracted tremendous interest in CO2 ***,we report a joint experimental-computational mechanistic study of photoreduction CO2 to CO on the model catalyst 9-hydroxyphenal-1-one(HPHN) CQDs with known *** theoretical calculations reveal that the rate-determining step is COOH·formation,which is closely related to the proton and electron transfer induced by hydrogen bonding in the excited *** to the calculated volcano plot,the solution we proposed is addition Zn^(2+) *** active center changed from the hydroxyl oxygen atom to the Zn atom and the barrier of the COOH·formation step is noticeably decreased when Zn^(2+) ions are *** is further confirmed by the experimental data that the activity of CO2 reduction increases 2.9 times when Zn^(2+) ions are added.

关键词： CO2 reduction dft study Reaction mechanism Hydrogen bonding Excited state

Single-atom Co-N_(4)catalytic sites anchored on N-doped ordered mesoporous carbon for excellent Zn-air batteries

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第8期139卷 224-231页

作者： Na Li Le Li Jiawei Xia Muhammad Arif Shilong Zhou Fengxiang Yin Guangyu He Haiqun Chen Key Laboratory of Advanced Catalytic Materials and Technology Advanced Catalysis and Green Manufacturing Collaborative Innovation CenterChangzhou UniversityChangzhou 213164China

Developing efficient transition metal-nitrogen-carbon(TM-N-C)catalysts with abundant accessible active sites has been in the limelight in recent years due to their exceptional application potential in Zn-air bat-teries(ZABs).Herein,we report the simple and environmentally-friendly fabrication of a single-atom Co electrocatalyst,Co-SA/N-C_(900),via in-suit pyrolysis of the co-precursor containing sucrose,dicyandiamide,and Co *** Co single atoms coordinated with adjacent N atoms are anchored on the doped ordered mesoporous carbon,generating the atomic Co-N_(4)***-SA/N-C_(900)displays high oxygen reduction reaction(ORR)activity with an onset potential of 0.96 V and a half-wave potential of 0.87 ***,the liquid ZAB with Co-SA/N-C_(900)catalyst exhibits exceptional discharge specific capacity of 706.38 mAh g^(-1),peak power density of 191.11 mW cm^(-2),and excellent stability at high current densities up to 100 mA cm^(-2),surpassing commercial Pt/*** to the density functional theory(dft)study,the Co-N_(4)moi-ety with graphitic N dopants can decrease the rate-determining step(RDS)energy barrier and thus accel-erate the ORR *** study offers experimental and theoretical guidelines for the rational design of TM-N-C catalysts for practical implementation with notable ORR activity for application in ZABs.

关键词： Single-atom electrocatalyst Co-N_(4)active sites Oxygen reduction reaction Zn-air battery dft study

Dual ligands relay-promoted transformation of unstrained ketones to polyfluoroarenes and nitriles

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2023年第7期66卷 2037-2045页

作者： Zhen-Yu Wang Huiying Xu Xu Zhang Xing Wang Hui Xu Hui Gao Hui-Xiong Dai School of Chinese Materia Medica Nanjing University of Chinese MedicineNanjing 210023China CAS Key Laboratory of Receptor Research State Key Laboratory of Drug ResearchShanghai Institute of Materia MedicaChinese Academy of SciencesShanghai 201203China School of Pharmaceutical Sciences Guangzhou Medical UniversityGuangzhou 511436China University of Chinese Academy of Sciences Beijing 100049China

C-C bond activation has emerged as a powerful tool for the construction of complex ***,we report a dual ligands relay-promoted transformation of unstrained aryl,alkenyl and alkynyl ketones to the corresponding polyfluoroarenes and nitriles via C-C(=O)bond cleavage and subsequent decarboxylative arylation *** polyfluoroarene and nitrile products are obtained in one pot under cyanide-free *** protocol features high atom economy,broad functional group tolerance and excellent heterocyclic *** late-stage functionalization of the drug and natural product demonstrated the synthetic utility of our ***,the decisive role of the dual ligands was clarified and the mechanistic rationale including theβ-C elimination as the rate-limiting step was supported by detailed density functional theory(dft)studies.

关键词： C-C bond activation dual ligands relay unstrained ketones modification of drugs and natural products dft study

同方期刊数据库

Theoretical insight into the activity and selectivity in palladium/Ming-Phos-catalyzed three-component asymmetric synthesis of gem-diarylmethine silanes

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2023年第10期66卷 2817-2827页

作者： Bo Xiao Tian-Yu Sun Junliang Zhang Yun-Dong Wu State Key Laboratory of Chemical Oncogenomics Key Laboratory of Computational Chemistry and Drug DesignSchool of Chemical Biology and BiotechnologyPeking University Shenzhen Graduate SchoolShenzhen 518055China Institute of Chemical Biology Shenzhen Bay LaboratoryShenzhen 518132China Department of Chemistry Fudan UniversityShanghai 200438China College of Chemistry and Molecular Engineering Peking UniversityBeijing 100871China

Recently,a three-component coupling reaction for efficient construction of gem-diarylmethine silanes was developed,utilizing a Pd-Ming-Phos *** explore the underlying mechanism governing this intriguing reaction,we have conducted comprehensive density functional theory(dft)computations(M06-L/SDD/6-311++G(d,p)/SMD//B3LYP-D3/lanl2dz/6-31G(d,p)).dft calculations reveal that the oxidative addition of Ar Br to Pd(0)is the rate-determining step,and the carbenation process of Ph CHN_(2)to Pd(Ⅱ)is the enantioselectivity-determining ***,the Ming-Phos ligand exhibits a self-adaptive nature,allowing it to dynamically adapt its coordination patterns with the metal center in different elementary steps,thereby enhancing the overall *** enantioselectivity is determined by both the trans effect and the side-arm effect of the *** mechanism nicely explains why TY-Phos with P-tBu_(2)instead of the Ming-Phos with P-Ph2results in poor reactivity and much reduced *** study not only provides deeper insights into the functioning principles of Sad Phos ligands but also offers valuable guidance for future ligand modifications and optimizations.

关键词： self-adaptive effect side-arm effect Ming-Phos ligand gem-diarylmethine silanes dft study

Theoretical insights into the [4+2]/retro [4+2] cycloaddition approach to the synthesis of biaryls and polycyclic aromatics

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2013年第5期56卷 633-640页

作者： LI XinYao XU JiaXi State Key Laboratory of Chemical Resource Engineering Department of Organic Chemistry Faculty of Science Beijing University of Chemical Technology

A domino [4+2]/retro [4+2] cycloaddition process of cyclohexadienes with arylethynes or benzyne providing access to biaryls and polycyclic aromatics has been studied theoretically using density functional theory calculations. It has been found that the initial Diels-Alder (D-A) reaction acts as the rate-determining step and the consequent [4+2] cycloreversion reaction is feasible under the conditions used. Furthermore, the D-A reaction affects the regioselectivity, the origin of which is essentially derived from the good match of orbital coefficients between dienes and dienophiles as shown by using frontier molecular orbital (FMO) theory. Further investigation of the reactivity reveals that the reactions are predicted to fail to occur if an electron-donor group in the diene or an electron-acceptor group in the dienophile is lacking, as a consequence of the increased FMO energy gap. By further exploring the scope of substrates computationally, benzyne as an active dienophile was predicted to react with a variety of dienes in a cascade reaction under mild conditions with a low energy barrier, with the rate-determining step being the retro [4+2] cycloaddition.

关键词： [4+2]/retro [4+2] cycloaddition biaryls polycyclic aromatics regioselectivity dft study

Exploring the pivotal role of silver(Ⅰ) additives in palladium-catalyzed NH_(2)-directed C(sp^(3))–H arylation reactions

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2021年第12期32卷 3980-3983页

作者： Ning Zhao Xiaojiao Jin Yanfeng Dang Tianjin Key Laboratory of Molecular Optoelectronic Sciences Department of ChemistryTianjin UniversityTianjin 300072China

Combined theoretical and experimental studies have explained the mechanism of Pd-catalyzed δ-C(sp^(3))-H arylation of primary amines. Instead of the monomeric Pd mechanism, our research unveils that all steps including C–H activation, oxidative addition, and reductive elimination take place via the heterodimeric Pd–Ag intermediates and transition states. Experimentally, the active heterodimeric Pd–Ag species were detected by mass spectrometry, which further confirms the proposed heterodimeric mechanism. Insight gained through this study reveals the synergistic manner of palladium catalysis and silver(Ⅰ)additives in native NH;-directed C–H activation and C–C coupling reactions.

关键词： Palladium catalysis Silver(Ⅰ)additive C(sp^(3))–H arylation Heterodimeric mechanism dft study

Quasi-Grotthuss mechanism in a nonporous sulphate

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2021年第6期30卷 233-237,I0007页

作者： Bo Li Yinuo Wang Jiasheng Wang Xue Yong Jingping Zhang Heibei Key Laboratory of Hazardous Chemicals Safety and Control Technology School of Chemical and Environmental EngineeringNorth China Institute of Science and TechnologyLangfang 065201HebeiChina Faculty of Chemistry Northeast Normal UniversityChangchun 130024JilinChina Department of Physics and Engineering Physics University of Saskatchewan116 Science PlaceSaskatoonSK S7N 5E2Canada State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022JilinChina

The transportation of the proton,the smallest ion in nature,is rudimentary in chemical and biological reactions[1,2],such as photosynthesis[3],enzyme catalysis[4],and Brensted acid/base reactions[5],and currently even imperative in some devices,namely proton exchange membrane fuel cells(PEMFCs)[6,7].The processes of these elementary reactions,like proton transfer,appear to be astonishingly analogous.

关键词： Quasi-Grotthuss mechanism Proton transfer Nonporous sulphate dft study