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Sun J, Yin Y, Li W, Jin O, Na N. CHEMICAL REACTION MONITORING BY AMBIENT MASS SPECTROMETRY. MASS SPECTROMETRY REVIEWS 2022; 41:70-99. [PMID: 33259644 DOI: 10.1002/mas.21668] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/16/2020] [Accepted: 10/22/2020] [Indexed: 06/12/2023]
Abstract
Chemical reactions conducted in different media (liquid phase, gas phase, or surface) drive developments of versatile techniques for the detection of intermediates and prediction of reasonable reaction pathways. Without sample pretreatment, ambient mass spectrometry (AMS) has been applied to obtain structural information of reactive molecules that differ in polarity and molecular weight. Commercial ion sources (e.g., electrospray ionization, atmospheric pressure chemical ionization, and direct analysis in real-time) have been reported to monitor substrates and products by offline reaction examination. While the interception or characterization of reactive intermediates with short lifetime are still limited by the offline modes. Notably, online ionization technologies, with high tolerance to salt, buffer, and pH, can achieve direct sampling and ionization of on-going reactions conducted in different media (e.g., liquid phase, gas phase, or surface). Therefore, short-lived intermediates could be captured at unprecedented timescales, and the reaction dynamics could be studied for mechanism examinations without sample pretreatments. In this review, via various AMS methods, chemical reaction monitoring and mechanism elucidation for different classifications of reactions have been reviewed. The developments and advances of common ionization methods for offline reaction monitoring will also be highlighted.
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Affiliation(s)
- Jianghui Sun
- Key Laboratory of Radiopharmaceuticals Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, People's Republic of China
| | - Yiyan Yin
- Key Laboratory of Radiopharmaceuticals Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, People's Republic of China
| | - Weixiang Li
- Key Laboratory of Radiopharmaceuticals Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, People's Republic of China
| | - Ouyang Jin
- Key Laboratory of Radiopharmaceuticals Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, People's Republic of China
| | - Na Na
- Key Laboratory of Radiopharmaceuticals Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, People's Republic of China
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2
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Zhao R, Zeng BL, Jia WQ, Zhao HY, Shen LY, Wang XJ, Pan XD. LiCl-promoted amination of β-methoxy amides (γ-lactones). RSC Adv 2020; 10:34938-34942. [PMID: 35514391 PMCID: PMC9056935 DOI: 10.1039/d0ra07170f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 09/11/2020] [Indexed: 12/21/2022] Open
Abstract
An efficient and mild method has been developed for the amination of β-methoxy amides (γ-lactones) including natural products michelolide, costunolide and parthenolide derivatives by using lithium chloride in good yields. This reaction is applicable to a wide range of substrates with good functional group tolerance. Mechanism studies show that the reactions undergo a LiCl promoted MeOH elimination from the substrates to form the corresponding α,β-unsaturated intermediates followed by the Michael addition of amines. The amination of β-methoxy amides (γ-lactones) including natural products michelolide, costunolide and parthenolide derivatives were first developed by using lithium chloride.![]()
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Affiliation(s)
- Ru Zhao
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences Beijing 100050 China
| | - Bing-Lin Zeng
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences Beijing 100050 China
| | - Wen-Qiang Jia
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences Beijing 100050 China
| | - Hong-Yi Zhao
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences Beijing 100050 China
| | - Long-Ying Shen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences Beijing 100050 China
| | - Xiao-Jian Wang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences Beijing 100050 China
| | - Xian-Dao Pan
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences Beijing 100050 China .,School of Pharmacy, Anhui University of Chinese Medicine Hefei 230012 China
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Zhang H, Qiao L, Wang W, He J, Yu K, Yang M, You H, Jiang J. Nebulization prior to ionization for mechanistic studies of chemical reactions. Anal Chim Acta 2020; 1107:107-112. [PMID: 32200884 DOI: 10.1016/j.aca.2020.02.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 02/12/2020] [Accepted: 02/14/2020] [Indexed: 10/25/2022]
Abstract
Many important chemical transformations proceed by way of ionic and/or neutral intermediates. Great effort has been expended to understand the mechanism, with only minimum attention given to separate associated ionic and neutral intermediates. Herein, we present a nebulization method followed by on-line ionization to isolate and characterize the ionic and neutral intermediates. The separation of nebulization and ionization and electrical deflection of ionic species guarantee that only neutrals undergo the subsequent on-line ionization. We present data that show the formation of neutral intermediates and iminium ions with short lifetime in Eschweiler-Clarke methylation of di-n-butylamine, as well as data that provide evidence for the formation of carbocation and its isomer lactone products resulting from copper-mediated oxidative cyclization of 4-phenylbutyric acid. Experiments in which dissociation behavior of these two isomers varied at the same collision energy confirmed the carbocation during the cyclization. The nature of this process, which online isolates the ionic and neutral intermediates prior to ionization, greatly advances in mechanistic studies.
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Affiliation(s)
- Hong Zhang
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, 264209, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Lina Qiao
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Wenxin Wang
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, 264209, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Jing He
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, 264209, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Kai Yu
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, 264209, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Miao Yang
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, 264209, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Hong You
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, 264209, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Jie Jiang
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai, 264209, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China.
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4
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M Ribeiro FW, Rodrigues-Oliveira AF, C Correra T. Benzoxazine Formation Mechanism Evaluation by Direct Observation of Reaction Intermediates. J Phys Chem A 2019; 123:8179-8187. [PMID: 31483645 DOI: 10.1021/acs.jpca.9b05065] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Benzoxazine formation is a fundamental step in the preparation of polybenzoxazine resins, and a detailed description of the mechanism governing the formation of benzoxazine and side products is vital for improving the properties and performance of these resins. Determination of the nature and properties of reaction intermediates is not trivial. Therefore, a Mannich-type condensation of aniline, formaldehyde, and phenol was evaluated as a potential method to form benzoxazine. Coupling positive mode electrospray ionization mass spectrometry (ESI(+)-MS) with infrared multiple photon dissociation (IRMPD) spectroscopy allowed unambiguous determination of an iminium-based mechanism and the direct observation of iminium intermediates. The benzoxazine formation mechanism was indirectly confirmed by the observation of side products that are relevant to the polymerization step, and directly confirmed by the identification of four distinct reaction intermediates that were completely characterized by IRMPD spectroscopy. The benzoxazine monomer was also shown to undergo isomerization under standard ESI-MS analysis conditions, suggesting the presence of a mixture of three isomers during their usual ESI-MS analysis.
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Affiliation(s)
- Francisco W M Ribeiro
- Department of Fundamental Chemistry, Institute of Chemistry , University of São Paulo Av. Prof. Lineu Prestes, 748, Cidade Universitária , São Paulo , São Paulo 05508-000 , Brazil
| | - André F Rodrigues-Oliveira
- Department of Fundamental Chemistry, Institute of Chemistry , University of São Paulo Av. Prof. Lineu Prestes, 748, Cidade Universitária , São Paulo , São Paulo 05508-000 , Brazil
| | - Thiago C Correra
- Department of Fundamental Chemistry, Institute of Chemistry , University of São Paulo Av. Prof. Lineu Prestes, 748, Cidade Universitária , São Paulo , São Paulo 05508-000 , Brazil
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5
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Falcone CE, Jaman Z, Wleklinski M, Koswara A, Thompson DH, Cooks RG. Reaction screening and optimization of continuous-flow atropine synthesis by preparative electrospray mass spectrometry. Analyst 2018; 142:2836-2845. [PMID: 28703239 DOI: 10.1039/c7an00622e] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Preparative electrospray (ES) exploits the acceleration of reactions in charged microdroplets to perform a small scale chemical synthesis. In combination with on-line mass spectrometric (MS) analysis, it constitutes a rapid screening tool to select reagents to generate specific products. A successful reaction in preparative ES triggers a refined microfluidic reaction screening procedure which includes the optimization for stoichiometry, temperature and residence time. We apply this combined approach for refining a flow synthesis of atropine. A successful preparative ES pathway for the synthesis of the phenylacetyl ester intermediate, using tropine/HCl/phenylacetyl chloride, was optimized for solvent in both the preparative ES and microfluidics flow systems and a base screening was conducted by both methods to increase atropine yield, increase percentage conversion and reduce byproducts. In preparative ES, the first step yielded 55% conversion (judged using MS) to intermediate and the second step yielded 47% conversion to atropine. When combined in two discrete steps in continuous-flow microfluidics, a 44% conversion of the starting material and a 30% actual yield of atropine were achieved. When the reactions were continuously telescoped in a new form of preparative reactive extractive electrospray (EES), atropine was synthesized with a 24% conversion. The corresponding continuous-flow microfluidics experiment gave a 55% conversion with an average of 34% yield in 8 min residence time. This is the first in depth study to utilize telescoped preparative ES and the first use of dual ESI emitters for multistep synthesis.
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Affiliation(s)
- Caitlin E Falcone
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907, USA.
| | - Zinia Jaman
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907, USA.
| | - Michael Wleklinski
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907, USA.
| | - Andy Koswara
- Chemical Engineering, Purdue University, 480 W Stadium Ave., West Lafayette, IN 47907, USA
| | - David H Thompson
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907, USA.
| | - R Graham Cooks
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907, USA.
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6
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Shin E, Cha S. In Situ
Probing Citrullinated Sites in a Peptide by Reactive Desorption Electrospray Ionization Mass Spectrometry. B KOREAN CHEM SOC 2017. [DOI: 10.1002/bkcs.11337] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Eunbi Shin
- Department of Chemistry; Hankuk University of Foreign Studies; Yongin Kyunggi-Do 17035 Korea
| | - Sangwon Cha
- Department of Chemistry; Hankuk University of Foreign Studies; Yongin Kyunggi-Do 17035 Korea
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7
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Meher AK, Chen YC. Electrospray Modifications for Advancing Mass Spectrometric Analysis. ACTA ACUST UNITED AC 2017; 6:S0057. [PMID: 28573082 DOI: 10.5702/massspectrometry.s0057] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 12/30/2016] [Indexed: 11/23/2022]
Abstract
Generation of analyte ions in gas phase is a primary requirement for mass spectrometric analysis. One of the ionization techniques that can be used to generate gas phase ions is electrospray ionization (ESI). ESI is a soft ionization method that can be used to analyze analytes ranging from small organics to large biomolecules. Numerous ionization techniques derived from ESI have been reported in the past two decades. These ion sources are aimed to achieve simplicity and ease of operation. Many of these ionization methods allow the flexibility for elimination or minimization of sample preparation steps prior to mass spectrometric analysis. Such ion sources have opened up new possibilities for taking scientific challenges, which might be limited by the conventional ESI technique. Thus, the number of ESI variants continues to increase. This review provides an overview of ionization techniques based on the use of electrospray reported in recent years. Also, a brief discussion on the instrumentation, underlying processes, and selected applications is also presented.
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Affiliation(s)
| | - Yu-Chie Chen
- Department of Applied Chemistry, National Chiao Tung University
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8
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Zheng Q, Chen H. Development and Applications of Liquid Sample Desorption Electrospray Ionization Mass Spectrometry. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2016; 9:411-448. [PMID: 27145689 DOI: 10.1146/annurev-anchem-071015-041620] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Desorption electrospray ionization mass spectrometry (DESI-MS) is a recent advance in the field of analytical chemistry. This review surveys the development of liquid sample DESI-MS (LS-DESI-MS), a variant form of DESI-MS that focuses on fast analysis of liquid samples, and its novel analy-tical applications in bioanalysis, proteomics, and reaction kinetics. Due to the capability of directly ionizing liquid samples, liquid sample DESI (LS-DESI) has been successfully used to couple MS with various analytical techniques, such as microfluidics, microextraction, electrochemistry, and chromatography. This review also covers these hyphenated techniques. In addition, several closely related ionization methods, including transmission mode DESI, thermally assisted DESI, and continuous flow-extractive DESI, are briefly discussed. The capabilities of LS-DESI extend and/or complement the utilities of traditional DESI and electrospray ionization and will find extensive and valuable analytical application in the future.
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Affiliation(s)
- Qiuling Zheng
- Center for Intelligent Chemical Instrumentation, Department of Chemistry and Biochemistry, and Edison Biotechnology Institute, Ohio University, Athens, Ohio 45701;
| | - Hao Chen
- Center for Intelligent Chemical Instrumentation, Department of Chemistry and Biochemistry, and Edison Biotechnology Institute, Ohio University, Athens, Ohio 45701;
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9
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Zhang JT, Wang HY, Zhang X, Zhang F, Guo YL. Study of short-lived and early reaction intermediates in organocatalytic asymmetric amination reactions by ion-mobility mass spectrometry. Catal Sci Technol 2016. [DOI: 10.1039/c6cy01051b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A study of the reactive intermediates in organocatalytic asymmetric amination reactions by reactive SAESI coupled to ion-mobility mass spectrometry.
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Affiliation(s)
- Jun-Ting Zhang
- State Key Laboratory of Organometallic Chemistry and National Center for Organic Mass Spectrometry in Shanghai
- Shanghai Institute of Organic Chemistry
- Chinese Academy of Sciences
- Shanghai 200032
- China
| | - Hao-Yang Wang
- State Key Laboratory of Organometallic Chemistry and National Center for Organic Mass Spectrometry in Shanghai
- Shanghai Institute of Organic Chemistry
- Chinese Academy of Sciences
- Shanghai 200032
- China
| | - Xiang Zhang
- Department of Applied Chemistry
- Zhejiang Gongshang University
- Hangzhou 310035
- China
| | - Fang Zhang
- State Key Laboratory of Organometallic Chemistry and National Center for Organic Mass Spectrometry in Shanghai
- Shanghai Institute of Organic Chemistry
- Chinese Academy of Sciences
- Shanghai 200032
- China
| | - Yin-Long Guo
- State Key Laboratory of Organometallic Chemistry and National Center for Organic Mass Spectrometry in Shanghai
- Shanghai Institute of Organic Chemistry
- Chinese Academy of Sciences
- Shanghai 200032
- China
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10
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Zhang W, Huang G. Fast screening of analytes for chemical reactions by reactive low-temperature plasma ionization mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2015; 29:1947-1953. [PMID: 26443392 DOI: 10.1002/rcm.7300] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 08/01/2015] [Accepted: 08/04/2015] [Indexed: 06/05/2023]
Abstract
RATIONALE Approaches for analyte screening have been used to aid in the fine-tuning of chemical reactions. Herein, we present a simple and straightforward analyte screening method for chemical reactions via reactive low-temperature plasma ionization mass spectrometry (reactive LTP-MS). METHODS Solution-phase reagents deposited on sample substrates were desorbed into the vapor phase by action of the LTP and by thermal desorption. Treated with LTP, both reagents reacted through a vapor phase ion/molecule reaction to generate the product. Finally, protonated reagents and products were identified by LTP-MS. RESULTS Reaction products from imine formation reaction, Eschweiler-Clarke methylation and the Eberlin reaction were detected via reactive LTP-MS. Products from the imine formation reaction with reagents substituted with different functional groups (26 out of 28 trials) were successfully screened in a time of 30 s each. Besides, two short-lived reactive intermediates of Eschweiler-Clarke methylation were also detected. CONCLUSIONS LTP in this study serves both as an ambient ionization source for analyte identification (including reagents, intermediates and products) and as a means to produce reagent ions to assist gas-phase ion/molecule reactions. The present reactive LTP-MS method enables fast screening for several analytes from several chemical reactions, which possesses good reagent compatibility and the potential to perform high-throughput analyte screening. In addition, with the detection of various reactive intermediates (intermediates I and II of Eschweiler-Clarke methylation), the present method would also contribute to revealing and elucidating reaction mechanisms.
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Affiliation(s)
- Wei Zhang
- Department of Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China (USTC), Hefei, 230026, P.R. China
| | - Guangming Huang
- Department of Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China (USTC), Hefei, 230026, P.R. China
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11
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Ingram AJ, Boeser CL, Zare RN. Going beyond electrospray: mass spectrometric studies of chemical reactions in and on liquids. Chem Sci 2015; 7:39-55. [PMID: 28757996 PMCID: PMC5508663 DOI: 10.1039/c5sc02740c] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 10/01/2015] [Indexed: 12/16/2022] Open
Abstract
Recently developed and applied ionization techniques have brought mass spectrometry to bear on previously inaccessible chemistry. We offer our perspective on this field and its application for studying reaction mechanisms.
There has been a burst in the number and variety of available ionization techniques to use mass spectrometry to monitor chemical reactions in and on liquids. Chemists have gained the capability to access chemistry at unprecedented timescales, and monitor reactions and detect intermediates under almost any set of conditions. Herein, recently developed ionization techniques that facilitate mechanistic studies of chemical processes are reviewed. This is followed by a discussion of our perspective on the judicious application of these and similar techniques in order to study reaction mechanisms.
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Affiliation(s)
- Andrew J Ingram
- Department of Chemistry , Stanford University , Stanford , CA 94305 , USA .
| | | | - Richard N Zare
- Department of Chemistry , Stanford University , Stanford , CA 94305 , USA .
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12
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13
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Boeser CL, Holder JC, Taylor BLH, Houk KN, Stoltz BM, Zare RN. Mechanistic analysis of an asymmetric palladium-catalyzed conjugate addition of arylboronic acids to β-substituted cyclic enones. Chem Sci 2015; 6:1917-1922. [PMID: 25729560 PMCID: PMC4338963 DOI: 10.1039/c4sc03337j] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 12/13/2014] [Indexed: 11/21/2022] Open
Abstract
An asymmetric palladium-catalyzed conjugate addition reaction of arylboronic acids to enone substrates was investigated mechanistically. Desorption electrospray ionization coupled to mass spectrometry was used to identify intermediates of the catalytic cycle and delineate differences in substrate reactivity. Our findings provide evidence for the catalytic cycle proceeding through formation of an arylpalladium(II) cation, subsequent formation of an arylpalladium-enone complex, and, ultimately, formation of the new C-C bond. Reaction monitoring in both positive and negative ion modes revealed that 4-iodophenylboronic acid formed a relatively stable trimeric species under the reaction conditions.
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Affiliation(s)
| | - Jeffrey C. Holder
- The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of TechnologyPasadenaCalifornia 91125USA
| | - Buck L. H. Taylor
- Department of Chemistry and Biochemistry, University of CaliforniaLos AngelesCalifornia 90095USA
| | - K. N. Houk
- Department of Chemistry and Biochemistry, University of CaliforniaLos AngelesCalifornia 90095USA
| | - Brian M. Stoltz
- The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of TechnologyPasadenaCalifornia 91125USA
| | - Richard N. Zare
- Department of Chemistry, Stanford UniversityStanfordCA 94305USA
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14
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Bain RM, Pulliam CJ, Cooks RG. Accelerated Hantzsch electrospray synthesis with temporal control of reaction intermediates. Chem Sci 2014; 6:397-401. [PMID: 28694938 PMCID: PMC5485237 DOI: 10.1039/c4sc02436b] [Citation(s) in RCA: 141] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 08/28/2014] [Indexed: 12/18/2022] Open
Abstract
Complex chemical reactions can occur in electrosprayed droplets on the millisecond time scale. The Hantzsch synthesis of 1,4-dihydropyridines was studied in this way using on-line mass spectral analysis to optimize conditions and characterize the product mixture. Changing the distance between the nanospray source and the MS inlet allowed exploration of reaction progress as a function of droplet time-of-flight. Desolvation of the charged microdroplets is associated with transformation from starting material to intermediates and eventually to product as the distance is increased. Results of the on-line experiments require a termination step that discontinuously completes the desolvation process and allows the generated gaseous ions to be used to characterize the state of the system at a particular time. The intermediates seen correspond to those known to occur in the bulk solution-phase reaction. Off-line collection of the sprayed reaction mixture allowed the recovery of 250 mg h-1 of desired reaction product from a single sprayer, permitting characterization by NMR and other standard methods. A thin film version of the accelerated reaction is described and it could be controlled through the temperature of the collection surface.
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Affiliation(s)
- Ryan M Bain
- Department of Chemistry , Purdue University , West Lafayette , IN 47907 , USA . ; ; Tel: +1-765-494-5263
| | - Christopher J Pulliam
- Department of Chemistry , Purdue University , West Lafayette , IN 47907 , USA . ; ; Tel: +1-765-494-5263
| | - R Graham Cooks
- Department of Chemistry , Purdue University , West Lafayette , IN 47907 , USA . ; ; Tel: +1-765-494-5263.,Center for Analytical Instrumentation Development , Purdue University , West Lafayette , IN 47909 , USA
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15
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Espy RD, Wleklinski M, Yan X, Cooks RG. Beyond the flask: Reactions on the fly in ambient mass spectrometry. Trends Analyt Chem 2014. [DOI: 10.1016/j.trac.2014.02.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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16
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Sarkar D, Sen Gupta S, Narayanan R, Pradeep T. Studying reaction intermediates formed at graphenic surfaces. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2014; 25:380-387. [PMID: 24385398 DOI: 10.1007/s13361-013-0786-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Revised: 11/10/2013] [Accepted: 11/14/2013] [Indexed: 06/03/2023]
Abstract
We report in-situ production and detection of intermediates at graphenic surfaces, especially during alcohol oxidation. Alcohol oxidation to acid occurs on graphene oxide-coated paper surface, driven by an electrical potential, in a paper spray mass spectrometry experiment. As paper spray ionization is a fast process and the time scale matches with the reaction time scale, we were able to detect the intermediate, acetal. This is the first observation of acetal formed in surface oxidation. The process is not limited to alcohols and the reaction has been extended to aldehydes, amines, phosphenes, sugars, etc., where reaction products were detected instantaneously. By combining surface reactions with ambient ionization and mass spectrometry, we show that new insights into chemical reactions become feasible. We suggest that several other chemical transformations may be studied this way. This work opens up a new pathway for different industrially and energetically important reactions using different metal catalysts and modified substrate.
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Affiliation(s)
- Depanjan Sarkar
- Thematic Unit of Excellence and DST Unit of Nanoscience (DST UNS), Department of Chemistry, Indian Institute of Technology Madras, Chennai, 600036, India
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17
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Chung K, Banik SM, De Crisci AG, Pearson DM, Blake TR, Olsson JV, Ingram AJ, Zare RN, Waymouth RM. Chemoselective Pd-catalyzed oxidation of polyols: synthetic scope and mechanistic studies. J Am Chem Soc 2013; 135:7593-602. [PMID: 23659308 DOI: 10.1021/ja4008694] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The regio- and chemoselective oxidation of unprotected vicinal polyols with [(neocuproine)Pd(OAc)]2(OTf)2 (1) (neocuproine = 2,9-dimethyl-1,10-phenanthroline) occurs readily under mild reaction conditions to generate α-hydroxy ketones. The oxidation of vicinal diols is both faster and more selective than the oxidation of primary and secondary alcohols; vicinal 1,2-diols are oxidized selectively to hydroxy ketones, whereas primary alcohols are oxidized in preference to secondary alcohols. Oxidative lactonization of 1,5-diols yields cyclic lactones. Catalyst loadings as low as 0.12 mol % in oxidation reactions on a 10 g scale can be used. The exquisite selectivity of this catalyst system is evident in the chemoselective and stereospecific oxidation of the polyol (S,S)-1,2,3,4-tetrahydroxybutane [(S,S)-threitol] to (S)-erythrulose. Mechanistic, kinetic, and theoretical studies revealed that the rate laws for the oxidation of primary and secondary alcohols differ from those of diols. Density functional theory calculations support the conclusion that β-hydride elimination to give hydroxy ketones is product-determining for the oxidation of vicinal diols, whereas for primary and secondary alcohols, pre-equilibria favoring primary alkoxides are product-determining. In situ desorption electrospray ionization mass spectrometry (DESI-MS) revealed several key intermediates in the proposed catalytic cycle.
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Affiliation(s)
- Kevin Chung
- Department of Chemistry, Stanford University, Stanford, California 94306, USA
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Badu-Tawiah AK, Eberlin LS, Ouyang Z, Cooks RG. Chemical aspects of the extractive methods of ambient ionization mass spectrometry. Annu Rev Phys Chem 2013; 64:481-505. [PMID: 23331308 DOI: 10.1146/annurev-physchem-040412-110026] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Ambient ionization techniques allow complex chemical samples to be analyzed in their native state with minimal sample preparation. This brings the obvious advantages of simplicity, speed, and versatility to mass spectrometry: Desorption electrospray ionization (DESI), for example, is used in chemical imaging for tumor margin diagnosis. This review on the extractive methods of ambient ionization focuses on chemical aspects, mechanistic considerations, and the accelerated chemical reactions occurring in charged liquid droplets generated in the spray process. DESI uses high-velocity solvent droplets to extract analytes from surfaces. Nano-DESI employs liquid microjunctions for analyte dissolution, whereas paper-spray ionization uses DC potentials applied to wet porous material such as paper or biological tissue to field emit charged analyte-containing solvent droplets. These methods also operate in a reactive mode in which added reagents allow derivatization during ionization. The accelerated reaction rates seen in charged microdroplets are useful in small-scale rapid chemical synthesis.
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Monge ME, Harris GA, Dwivedi P, Fernández FM. Mass Spectrometry: Recent Advances in Direct Open Air Surface Sampling/Ionization. Chem Rev 2013; 113:2269-308. [DOI: 10.1021/cr300309q] [Citation(s) in RCA: 404] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- María Eugenia Monge
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332,
United States
| | - Glenn A. Harris
- Department
of Biochemistry and
the Mass Spectrometry Research Center, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Prabha Dwivedi
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332,
United States
| | - Facundo M. Fernández
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332,
United States
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Perry RH, Cahill TJ, Roizen JL, Du Bois J, Zare RN. Capturing fleeting intermediates in a catalytic C-H amination reaction cycle. Proc Natl Acad Sci U S A 2012; 109:18295-9. [PMID: 23091019 PMCID: PMC3494934 DOI: 10.1073/pnas.1207600109] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We have applied an ambient ionization technique, desorption electrospray ionization MS, to identify transient reactive species of an archetypal C-H amination reaction catalyzed by a dirhodium tetracarboxylate complex. Using this analytical method, we have detected previously proposed short-lived reaction intermediates, including two nitrenoid complexes that differ in oxidation state. Our findings suggest that an Rh-nitrene oxidant can react with hydrocarbon substrates through a hydrogen atom abstraction pathway and raise the intriguing possibility that two catalytic C-H amination pathways may be operative in a typical bulk solution reaction. As highlighted by these results, desorption electrospray ionization MS should have broad applicability for the mechanistic study of catalytic processes.
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Affiliation(s)
| | | | | | - Justin Du Bois
- Department of Chemistry, Stanford University, Stanford, CA 94305-5080
| | - Richard N. Zare
- Department of Chemistry, Stanford University, Stanford, CA 94305-5080
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21
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Zhu W, Yuan Y, Zhou P, Zeng L, Wang H, Tang L, Guo B, Chen B. The expanding role of electrospray ionization mass spectrometry for probing reactive intermediates in solution. Molecules 2012; 17:11507-37. [PMID: 23018925 PMCID: PMC6268401 DOI: 10.3390/molecules171011507] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 08/29/2012] [Accepted: 09/05/2012] [Indexed: 12/31/2022] Open
Abstract
Within the past decade, electrospray ionization mass spectrometry (ESI-MS) has rapidly occupied a prominent position for liquid-phase mechanistic studies due to its intrinsic advantages allowing for efficient "fishing" (rapid, sensitive, specific and simultaneous detection/identification) of multiple intermediates and products directly from a "real-world" solution. In this review we attempt to offer a comprehensive overview of the ESI-MS-based methodologies and strategies developed up to date to study reactive species in reaction solutions. A full description of general issues involved with probing reacting species from complex (bio)chemical reaction systems is briefly covered, including the potential sources of reactive intermediate (metabolite) generation, analytical aspects and challenges, basic rudiments of ESI-MS and the state-of-the-art technology. The main purpose of the present review is to highlight the utility of ESI-MS and its expanding role in probing reactive intermediates from various reactions in solution, with special focus on current progress in ESI-MS-based approaches for improving throughput, testing reality and real-time detection by using newly developed MS instruments and emerging ionization sources (such as ambient ESI techniques). In addition, the limitations of modern ESI-MS in detecting intermediates in organic reactions is also discussed.
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Affiliation(s)
- Weitao Zhu
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, 36 Lushan Road, Changsha 410081, China; (W.Z.); (P.Z.); (L.Z.); (H.W.); (L.T.); (B.C.)
| | - Yu Yuan
- School of Pharmaceutical Sciences, Central South University, 172 Tongzipo Road, Changsha 410013, China;
| | - Peng Zhou
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, 36 Lushan Road, Changsha 410081, China; (W.Z.); (P.Z.); (L.Z.); (H.W.); (L.T.); (B.C.)
| | - Le Zeng
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, 36 Lushan Road, Changsha 410081, China; (W.Z.); (P.Z.); (L.Z.); (H.W.); (L.T.); (B.C.)
| | - Hua Wang
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, 36 Lushan Road, Changsha 410081, China; (W.Z.); (P.Z.); (L.Z.); (H.W.); (L.T.); (B.C.)
| | - Ling Tang
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, 36 Lushan Road, Changsha 410081, China; (W.Z.); (P.Z.); (L.Z.); (H.W.); (L.T.); (B.C.)
| | - Bin Guo
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, 36 Lushan Road, Changsha 410081, China; (W.Z.); (P.Z.); (L.Z.); (H.W.); (L.T.); (B.C.)
| | - Bo Chen
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, 36 Lushan Road, Changsha 410081, China; (W.Z.); (P.Z.); (L.Z.); (H.W.); (L.T.); (B.C.)
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Eftekhari M, Ismail AI, Zare RN. Isomeric differentiation of polycyclic aromatic hydrocarbons using silver nitrate reactive desorption electrospray ionization mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2012; 26:1985-1992. [PMID: 22847697 PMCID: PMC4145873 DOI: 10.1002/rcm.6309] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
RATIONALE Polycyclic aromatic hydrocarbons (PAHs) are nonpolar and difficult to detect by desorption electrospray ionization. We present a new detection method based on cationization with silver ions, which has the added advantage of being able to differentiate PAHs with the same mass but different structure. METHODS 9,10-Diphenylanthracene and triptycene, in addition to four different groups of PAH isomers: (1) anthracene and phenanthrene, (2) pyrene and fluoranthene, (3) benz[a]anthracene, benz[b]anthracene (tetracene), and chrysene (4) benzo[a]pyrene and benzo[k]fluoranthene, were deposited on a paper surface and bombarded with methanol droplets containing silver nitrate. The resulting microdroplets entered a quadruple mass spectrometer for mass analysis. RESULTS The mass spectrum shows [PAH](+), [Ag + OH + PAH](+), and [Ag(PAH)(n)](+) (n = 1, 2) (and [PAH + O(2)](+) in the case of benz[b]anthracene) ions. PAHs having a bay structure, such as phenanthrene, showed a different tendency to interact with silver ions from those PAHs having a linear arrangement of the fused benzene rings, such as anthracene. The ratios of the [PAH](+) peak intensity to that of [Ag-PAH](+), [Ag + OH + PAH](+), [Ag(PAH)(2)](+), and [PAH + O(2)](+) were used to differentiate the PAH isomers sharing the same molecular formula with different structures. For isomeric mixtures the [PAH](+) to [Ag + OH + PAH](+) ratio was found to be the most useful parameter. The uncertainty in the mole fraction of an isomeric mixture was ±0.09, ±0.13, ±0.25, and ±0.1 for phenanthrene-anthracene, fluoranthene-pyrene, benz[a]anthracene-chrysene, and benzo[a]pyrene-benzo[k]fluoranthene, respectively. CONCLUSIONS A simple method has been developed for the detection of PAHs in desorption electrospray ionization mass spectrometry based on Ag(I) cationization. The method showed a capability to differentiate PAHs isomers (having the same molecular mass) in isomeric mixture with an uncertainty in the mole fraction of about ±0.1. At high inlet temperature and voltage, this method showed better sensitivity but less ability to differentiate between isomeric species.
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Affiliation(s)
- Mohammad Eftekhari
- Department of Chemistry, Stanford University, Stanford, CA 94305-5080, USA
- Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Iran
| | - Ali I. Ismail
- Department of Chemistry, Stanford University, Stanford, CA 94305-5080, USA
| | - Richard N. Zare
- Department of Chemistry, Stanford University, Stanford, CA 94305-5080, USA
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Transient Ru-methyl formate intermediates generated with bifunctional transfer hydrogenation catalysts. Proc Natl Acad Sci U S A 2012; 109:2246-50. [PMID: 22315417 DOI: 10.1073/pnas.1118934109] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Desorption electrospray ionization (DESI) coupled to high-resolution Orbitrap mass spectrometry (MS) was used to study the reactivity of a (β-amino alcohol)(arene)RuCl transfer hydrogenation catalytic precursor in methanol (CH(3)OH). By placing [(p-cymene)RuCl(2)](2) on a surface and spraying a solution of β-amino alcohol in methanol, two unique transient intermediates having lifetimes in the submillisecond to millisecond range were detected. These intermediates were identified as Ru (II) and Ru (IV) complexes incorporating methyl formate (HCOOCH(3)). The Ru (IV) intermediate is not observed when the DESI spray solution is sparged with Ar gas, indicating that O(2) dissolved in the solvent is necessary for oxidizing Ru (II) to Ru (IV). These proposed intermediates are supported by high-resolution and high mass accuracy measurements and by comparing experimental to calculated isotope profiles. Additionally, analyzing the bulk reaction mixture using gas chromatography-MS and nuclear magnetic resonance spectroscopy confirms the formation of HCOOCH(3). These results represent an example that species generated from the (β-amino alcohol)(arene)RuCl (II) catalytic precursor can selectively oxidize CH(3)OH to HCOOCH(3). This observation leads us to propose a pathway that can compete with the hydrogen transfer catalytic cycle. Although bifunctional hydrogen transfer with Ru catalysts has been well-studied, the ability of DESI to intercept intermediates formed in the first few milliseconds of a chemical reaction allowed identification of previously unrecognized intermediates and reaction pathways in this catalytic system.
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