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Markovnikov-Selective Hydroboration of Aryl Alkenes Enabled by a Simple Nickel Salt

Chinese Journal of Chemistry 2022年第18期40卷 2203-2211页

作者： Tianfen Liu Chuhan Li Jiahui Bai Panke Zhang yinlong guo Xiaoming Wang Green Catalysis Center College of ChemistryZhengzhou University100 Science AvenueHigh-Tech DistrictZhengzhouHenan450001 China State Key Laboratory of Organometallic Chemistry Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of Sciences345 Lingling RoadShanghai200032 China School of Chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of Sciences1 Sub-lane XiangshanHangzhouZhejiang310024 China

The sustainable development of synthetic reactions catalyzed by earth-abundant metals is one of the principal goals in homogeneous ***,so far most of the protocols are still plagued by sophisticated ligands,hazardous activators,high catalyst loading(1—10 mol%)and/or multistep synthesis of the metal complexes in the process ***,the development of earth-abundant metal catalysts with high activity from commercially available metal salts is highly desirable for practical utilization of base metal catalyzed synthetic ***,we report the catalyst generated in situ from a mixture of catalytic amounts of Ni(acac)_(2)(as low as 0.005 mol%)and CsF,which is found highly active for Markovnikov-selective hydroboration of vinylarenes,including 1,1-disubstituted vinylarenes and internal olefins,affording a wide range of secondary and tertiary alkyl boronates in excellent *** experiments indicate that the key to the success of this catalysis is the use of CsF,which in combination with pinacolborane acts as an effective activator for Ni(acac)_(2),probably generating metastable Ni nanoparticles in situ that demonstrate high activity in the catalytic hydroboration(TON up to 18800).

关键词： Nickel salt Hydroboration Earth-abundant metal catalysis Nanoparticles

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Recent Advances in Atmospheric Ionization Mass Spectrometry:Developments and Applications

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Chinese Journal of Chemistry 2020年第1期38卷 25-38页

作者： Yuling Li Yuqi Cao yinlong guo State Key Laboratory of Organometallic Chemistry National Center for Organic Mass Spectrometry in ShanghaiShanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

Over the past 15 years,ambient ionization mass spectrometry has rapidly developed,greatly expanding the applications of single-cell analysis,food and agricultural,envi-ronmental,chemical analysis,biomedical analysis,mass spectrometry imaging,among other *** time mass spectrometry evaluations of living sample,such as in vivo direct analysis for single cell,clinical applications,metabolic monitoring of living species and transient intermediates in organic reactions,have demonstrated the power and potential significance of ambient ionization mass ***-in,we want to introduce a partial of our works atmospheric ionization mass spec-trometry,related to ambient ionization mass spectrometry.

关键词： ionization ambient analysis

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Analysis of Trace-Level Volatile Compounds in Fresh Turf Crop （Lolium perenne L.） by Gas Chromatography Quadrupole Time-of-Flight Mass Spectrometry

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Chinese Journal of Chemistry 2013年第10期31卷 1329-1335页

作者： Saisai Hong Wenyu Kang Yue Su yinlong guo Research Center for Health and Nutrition Shanghai University of Traditional Chinese Medicine Shanghai 201203 China Shanghai Mass Spectrometry Center Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 China

In the traditional research of volatile compounds, some trace-level compounds could not be identified by gas chromatography-mass spectrometry. Target and post-targeted methods were applied in the investigation of trace-level volatile compounds in fresh turf crop （Lolium perenne L.） based on gas chromatography in combination with hybrid quadrupole time-of-flight mass spectrometry. According to literatures published, a target analysis was performed by using retention index, accurate masses of characteristic ions and second-stage mass spectra （MS2 spectra）. And a series of experiments showed that low electron impact energy was beneficial to the improvement of the abundances of low abundance molecular ion peak. peak was beneficial to qualitative analysis. Totally, 60 Enhancing the abundances of low abundance molecular ion volatile compounds were identified, the great majority cornpounds of which were benzeneacetaldehyde （14.8%）, 2,5-dimethyl-pyrazine （9.6%）, and hexanal （9.3%）. Identification was complied by mass spectral search, retention index and accurate masses of characteristic ions.

关键词： GC-QTOF MS trace-level volatile compound target analysis post-targeted analysis

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Study on the Degradation of the Highly Reactive Hypervalent Trifluoromethylation Iodine Reagent PhI（OAc）（CF3）

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Chinese Journal of Chemistry 2015年第12期33卷 1365-1370页

作者： Hui Zhu Shusheng Zhang HaoyangWang Bin Xu yinlong guo Department of Chemistry Innovative Drug Research Center Shanghai University Shanghai 200444 China National Center for Organic Mass Spectrometry in Shanghai State Key Laboratory of Organmetallic Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 China

Degradation of the highly reactive hypervalent trifluoromethylation iodine reagent PhI（OAc）（CF3）, which can only be generated in situ with mixing PhI（OAc）2 and TMSCF3 in the presence of CsF, was studied by ESI-MS and GC-MS combined with ~9F-NMR. The important transient intermediate PhlCF3＋ was determined by ESI-MS, and the major volatile products containing CF3 were identified with the authentic compounds by using GC-MS, such as trifluoromethylbenzene, 2-iodobenzotrifluoride, 3-iodobenzotrifluoride, 4-iodobenzotrifluoride. Meanwhile, more evidences obtained with 19F-NMR were given for such degradation reaction. A possible rapid CF3 radical transfer reaction pathway was proposed to clarify such degradation progress based on the experimental results. Therefore, this study may be helpful in elucidating the intrinsic reactivity of PhI（OAc）（CF3） and the possible competing side reactions caused by such self-degradation pathway.

关键词： degradation trifluoromethylation iodine reagent mass spectrometry 19F-NMR CF3 radical reaction

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Study of the Transient Reactive Pd(Ⅳ) Intermediate in the Pd(OAc)2-Catalyzed Oxidative Coupling Reaction System by Electrospray Ionization Tandem Mass Spectrometry

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Chinese Journal of Chemistry 2013年第3期31卷 371-376页

作者： Wei Zhu Haoyang Wang Haihui Peng guosheng Liu yinlong guo Shanghai Mass Spectrometry Center Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 China

Pd-catalyzed oxidative coupling reaction was of great importance in the aromatic C--H activation and the for-mation of new C-O and C--C bonds. Sanford has pioneered practical, directed C-H activation reactions em-ploying Pd（OAc）2 as catalyst since 2004. However, until now, the speculated reactive Pd（Ⅳ） transient intermedi-ates in these reactions have not been isolated or directly detected from reaction solution. Electrospray ionization tandem mass spectrometry （ESI-MS/MS） was used to intercept and characterize the reactive Pd（Ⅳ） transient inter-mediates in the solutions of Pd（OAc）2-catalyzed oxidative coupling reactions. In this study, the Pd（IV） transient in-termediates were detected from the solution of Pd（OAc）2-catalyzed oxidative coupling reactions by ESI-MS and the MS/MS of the intercepted Pd（IV） transient intermediate in reaction system was the same with the synthesized au-thentic Pd（Ⅳ） complex. Our ESI-MS（/MS） studies confirmed the presence of Pd（Ⅳ） reaction transient intermedi-ates. Most interestingly, the MS/MS of Pd（Ⅳ） transient intermediates showed the reductive elimination reactivity to Pd（Ⅱ） complexes with new C-O bond formation into product in gas phase, which was consistent with the proposed reactivity of the Pd（Ⅳ） transient intermediates in solution.

关键词： electrospray ionization tandem mass spectrometry (ESI-MS/MS) Pd(IV) transient intermediate oxi^dative coupling reaction

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Behaviors of Leucine and Isoleucine in Ion Mobility- Quadrupole Time of Flight Mass Spectrometry

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Chinese Journal of Chemistry 2015年第12期33卷 1359-1364页

作者： Su guo Fang Zhang Haoyang Wang Manyu Zhang Zhixu Zhang Xiang Zhang yinlong guo National Center for Organic Mass Spectrometry in Shanghai Shanghai Institute of Organic Chemistry Chinese Academy of Sciences 345 Lingling Road Shanghai 200032 China Agilent Technologies (China) CO. Ltd. 1350 North Sichuan Road Shanghai 200080 China Department of Chemistry Fudan University 220 Handan Road Shanghai 200433 China School of Food Science and Biotechnology Zhejiang Gongshang University Hangzhou Zhejiang 310018 China

In this study, ion mobility separation coupled with tandem mass spectrometry （IM-tandem MS） was utilized to investigate the ionization behaviors of two amino acids including leucine and isoleucine. Under the electrospray ionization （ESI） mode, two protonation sites in each molecular sturcture caused two forms of protomer. One arose from the amino being protonated （amino-protomer） and the other from the carboxyl being protonated （car- boxyl-protomer）. In the two-dimensional （drift time, m/z） spectrum, the protomers had the same mass, but the dis- tinguishable drift times and fragmentation patterns. For the characterization purpose, the theoretical collision cross section （CCS） values of the protomers were calculated and proven to be consistent with the experimental. Moreover, the quantified relationship between the amino acids and their protomers was evaluated. It showed that the abun- dance of the carboxyl-protomer was proportional to the concentration of the amino acid, whereas that of the amino- protomer did not have the same trend. Under the atmospheric pressure chemical ionization （APCI） mode, only the carboxyl-protomer was observed. In addition, the amino-protomer and the cluster ions observed under ESI were absent completely. The results demonstrate that the ionization mode impacts heavily on the ionization behaviors of leucine and isoleucine not only on the form of therir protomers but also On the quantified relationship.

关键词： leucine isoleucine IM-tandem MS ESI APCI

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Combination of Solid-Phase Micro-Extraction and Direct Analysis in Real Time-Fourier Transform Ion Cyclotron Resonance Mass Spectrometry for Sensitive and Rapid Analysis of 15 Phthalate Plasticizers in Beverages

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中国化学:英文版 2015年第2期33卷 213-219页

作者： Mengxi Wu Haoyang Wang guoqing Dong Brian D.Musselman Charles C.Liu yinlong guo Shanghai Mass Spectrometry Center Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China IonSense Inc.999 BroadwaySuite 404SaugusMA 01906USA ASPEC Technologies Limited Room 1506RunFengDeShang Bldg ANo.60 An Li LuChaoyang DistrictBeijing 100101China

A method for rapid identification and quantification of phthalate plasticizers in beverages was developed.A number of 15 phthalate plasticizers which covered all the phthalates concerned in the US Consumer Product Safety Improvement Act(CPSIA),European Union legislations and Chinese national standards(GB)were *** a combined solid-phase micro-extraction(SPME)and direct analysis in real time mass spectrometry(DART-MS)approach,phthalates at sub-ng•mL^(−1)levels can be qualitatively and quantitatively analyzed in a short *** use of ultrahigh-resolving power and the accurate mass measurement capacity naturally provided by Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR-MS)minimizes the matrix interferences and thus enables the evaluation of phthalates in a complex matrix without extensive sample handlings or *** limits of quantification(LOQs)were estimated to be at 0.3-5.0 ng•mL^(−1),lower than the Maximum Residue Limit(MRL)regulated by the European Union legislations(2007/19/EC)in foods,beverages,food packaging and toys(0.3-30 ng•mL^(−1)).This rapid and easy-to-use SPME-DART-FT-ICR-MS method provided a relatively high-throughput and powerful analytical approach for quick testing and screening phthalates in beverages and water samples to ensure food safety.

关键词： solid-phase micro-extraction direct analysis in real time Fourier transform ion cyclotron resonance mass spectrometry phthalates

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Reliable screening of pesticide residues in maternal and umbilical cord sera by gas chromatography-quadrupole time of flight mass spectrometry

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Science China Chemistry 2014年第5期57卷 669-677页

作者： FAN RuoJing ZHANG Fang WANG HaoYang ZHANG Li ZHANG Jing ZHANG Ying YU ChongTian guo yinlong Shanghai Mass Spectrometry Center Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Department of Gynaecology and Obstetrics Yijishan Hospital of Wannan Medical College Agilent Technologies (China) CO. Ltd.

The widespread use of pesticides induces heavy adverse effects on human health,especially for the pregnant women and the *** this study,a screening method has been developed for the determination of multi-pesticides in maternal and umbilical cord *** pesticides in sera were collected using solid phase extraction(SPE),and analyzed by gas chromatography-quadrupole time of flight mass spectrometry(GC-QTOF MS).To set up the quality criteria,a database of 50 pesticides was created and the accurate masses of 3 up to 5 representative ions with their intensity ratios were included for each *** addition,a novel"identification points"(IPs)system relying on the accurate MS1 and MS2 spectra was used to interpret the data for each suspected *** methodology was then applied to a pair of maternal and umbilical cord sera.A total of six pesticide residues were screened out *** conclusion,GC-QTOF MS combined with an accurate mass database seemed to be one of the most efficient tools for systematic pesticide analysis.

关键词： pesticide residues screening maternal and umbilical cord sera gas chromatography-quadrupole time of flight massspectrometry

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Negishi Coupling for Highly Selective Syntheses of Allenes via Ligand Effect and Mechanistic Study via SAESI-MS/MS

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Chinese Journal of Chemistry 2019年第10期37卷 1003-1008页

作者： Yangguangyan Zheng Bukeyan Miao Anni Qin Junzhe Xiao Qi Liu Gen Li Li Zhang Fang Zhang yinlong guo Shengming Ma Department of Chemistry Fudan University220 Handan LuShanghai 200433China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of Sciences345 Lingling LuShanghai 200032China National Center for Organic Mass Spectrometry in Shanghai Shanghai Institute of Organic ChemistryChinese Academy of Sciences345 Lingling LuShanghai 200032China

β-H elimination is an intrinsic problem in transition metal-catalyzed *** describe herein an interesting ligand effect for Et2Zn acting as either ethyl provider or H provider,respectively:by applying SPhos or Gorlos-Phos as the ligand,β-H elimination has been successfully controlled in the corresponding Negishi coupling reaction affording different poly-substituted allenes in good yields and excellent ***-MS (Solvent Assisted Electrospray Ionization Mass Spectrometry) has been applied to successfully capture the highly reactive organometallic intermediates,which show the different coordination behaviors of Pd with SPhos or Gorlos-Phos as the ligand in the catalytic *** addition,the different reactivities of Int 1 and Int 2 towards the formation of the final allene products have been demonstrated via SAESI-MS/MS *** MS studies visualized the whole catalytic cycle for the Negishi coupling reaction while nicely explain the observed reactivity and selectivity.

关键词： elimination Highly substituted

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高压线下预制板梁采用双机抬吊的技术分析

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建筑施工 2022年第8期44卷 1984-1986页

作者：郭银龙上海建工一建集团有限公司上海200120

以桥梁的单跨预制空心板梁吊装施工为研究对象,着重阐述高压线下采取双机抬吊的施工技术。结合工程实例,对相关的技术难点和解决方法等进行论述,并对吊装使用的工具及地基承载力等进行验算,确保施工全过程的安全。

关键词：高压线空心板梁汽车吊验算

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