Polar Acetalization and Transacetalization in the Gas Phase:  The Eberlin Reaction

Cooks, R. Graham; Chen, Hao; Eberlin, Marcos N.; Zheng, Xubin; Tao, W. Andy

doi:10.1021/cr0400921

Cited by 86 publications

(46 citation statements)

References 242 publications

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“…As previous results with analogous immonium ions anticipate, [19], 1= and 2 also display very contrasting reactivity in polar transacetylization [20] (Table 1). In MS 3 experiments (spectra not shown), both cycloadducts were found to dissociate exclusively via retrocycloaddition to reform 2 [21].…”

Section: Intrinsic Chemistry Of Gaseous 1= Andsupporting

confidence: 85%

Recognition and resolution of isomeric alkyl anilines by mass spectrometry

Benassi

Corilo

Uria

et al. 2009

J. Am. Soc. Mass Spectrom.

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Two MS techniques have been used to recognize and resolve a representative isomeric pair of N-alkyl and ring-alkyl substituted anilines. The first technique (1) uses MS/MS to perform ion/molecule reactions of structurally-diagnostic fragment ions (SDFI) whereas the second (2) uses traveling wave ion mobility spectrometry (TWIMS) of the pair of protonated molecules followed by on-line collision-induced dissociation (CID), that is, MS/TWIMS-CID/MS. Isomeric C 7 H 7 N ϩ ions of m/z 106 (1= from 4-butylaniline and 2 from N-butylaniline) are formed as abundant fragments by 70 eV EI of the anilines, and found to function as suitable SDFI. Ions 1= and 2 display nearly identical unimolecular dissociation chemistry, but contrasting bimolecular reactivity with ethyl vinyl ether, isoprene, acrolein, and 2-methyl-1,3-dioxolane. Ion 2 forms adducts to a large extent whereas 1= is nearly inert towards all reactants tested. The intact protonated anilines are readily resolved and recognized by MS/TWIMS-CID/MS in a SYNAPT mass spectrometer (Waters Corporation, Manchester, UK). The protonated N-butyl aniline (the more compact isomer) displays shorter drift time and higher lability towards CID than its 4-butyl isomer. The general application of SDFI 1= and 2 and other homologous and analogous ions and MS/TWIMS-CID/MS for absolute recognition and resolution of isomeric families of N-alkyl and ring-alkyl mono-substituted anilines and analogues is discussed. somers have distinct structures and properties, but exactly the same mass. Mass spectrometry measures primarily mass; hence when dealing with intact gaseous species, MS is inherently blind for distinguishing isomers. Many MS strategies based on the correlation between structure and physicochemical properties, such as those exploring uni-or bimolecular reactivity, have therefore been developed to recognize and resolve gaseous isomeric ions [1]. Isomers sometimes display, however, very similar gaseous reactivities and still end up being indistinguishable by these approaches. Isomers have also been treated in case by case approaches and, up to now, no general MS strategy for isomer recognition and resolution is available.We have recently proposed a MS/MS strategy for wide-ranging, absolute (noncomparative) recognition and resolution of constitutional isomers based on structurally diagnostic fragment ions (SDFI) [2]. The main SDFI requisites are that they must: (1) be a fragment ion shared by most (ideally by all) members of the isomeric family; (2) contain and retain the structural information of its specific isomeric precursor; (3) be stable gaseous species with relatively high barriers for structural rearrangements, and (4) display contrasting dissociations or bimolecular reactivities, or both, induced and properly rationalized in terms of their distinct structures.Although the task is by no means easy, we have so far succeeded in finding several proper SDFI for different families of constitutional isomers. For instance, pyridinium ions function as SDFI for ortho, meta and para-s...

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Section: Intrinsic Chemistry Of Gaseous 1= Andsupporting

confidence: 85%

Recognition and resolution of isomeric alkyl anilines by mass spectrometry

Benassi

Corilo

Uria

et al. 2009

J. Am. Soc. Mass Spectrom.

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“…The ions at m/z 149 constitute a well-known characteristic for contamination from phthalate plasticizers [4]. They could also be viewed as a substituted acylium ion [PhOC¢O] ϩ that undergoes the gas-phase Meerwein reaction [24,25], as reported by Eberlin and Cooks. The reaction results in a stable product through three-to five-membered ring expansion and can explain the reason for the dominance of a single addition of EO.…”

Section: Efficient Reactions Of Ethylene Oxide (Eo) With Chemical Bacmentioning

confidence: 89%

Alternative reagents for chemical noise reduction in liquid chromatography-mass spectrometry using selective ion-molecule reactions

Guo

Bruins

Covey³

et al. 2009

J. Am. Soc. Mass Spectrom.

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Reduction of ionic chemical background noise based on selective gas-phase reactions with chosen neutral reagents has been proven to be a very promising approach in liquid chromatography-mass spectrometry (LC-MS). In this study further investigations on alternative reagents including the disulfides (dimethyl disulfide, diethyl disulfide, methyl propyl disulfide), dimethyl trisulfide, ethylene oxide, and butadiene monoxide, for example, have been carried out. Tandem mass spectrometric studies of ion/molecule reactions indicate that-besides dimethyl disulfide-ethylene oxide and butadiene monoxide also exhibit very efficient reactions with background ions. Furthermore, it is confirmed that the reactions are very selective according to the test with some analyte ions. In contrast to its rapid reactions with background ions, ethylene oxide does not react, or reacts much less, with these analytes. Therefore, it can be used as an alternative reagent for noise reduction. Although reactions of the other tested neutral reagents with background ions are evaluated, they are generally not suitable as reagents for this purpose because of lack of reactivity or dramatic ion losses during reactions. ( Most hardware approaches of noise reduction [6] focused on improving ionization selectivity, declustering (desolvation) conditions, ion transmission [7], preventing contamination from ion sources and tubing, and so forth. The comprehensive tandem mass spectrometry (MS/MS) scan modes, such as selected ion monitoring, multiple reaction monitoring, neutral loss scan, product ion scan, and precursor ion scan, can further improve the MS detection specificity. However, these MS/MS techniques are generally not suitable for trace analysis of unknowns, where analyte signals are generally as low as the chemical background ions in a full-scan mode.Enhancement of the signal-to-noise ratio (S/N) can also be achieved by reducing the level of background noise. The recent application of high-field asymmetry ion mobility spectrometry (FAIMS) [8] as an interfacing technique [9] in LC-MS is also aimed at the reduction or separation of ionic chemical noise to improve sensitivity. In addition to these hardware improvements, various off-line processing software programs have been developed and implemented into some commercial systems, such as the component detection algorithm (CODA) [10], the matched filtration with experimental noise determination [11], the sequential paired covariance [12], and other noise filtration methods [13]. Other software-assisted approaches such as dynamic background subtraction [14], active chemical background noise reduction [15], and windowed mass selection [16]

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“…ESI-MS is a soft ionizing technique, 1 which may allow an online monitoring of a plethora of reactions. Valuable information such as coordination, oxidation states of metal center and others may be obtained by ESI-MS.…”

Section: Introductionmentioning

confidence: 99%

Charge-tagged ligands derived of 1,3-imidazolium ion as catalyst precursor of copper, nickel and palladium

Oliveira¹,

Lalli²,

Schmidt³

et al. 2013

Proceedings of the 14th Brazilian Meeting on Organic Synthesis Proceedings

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Polar Acetalization and Transacetalization in the Gas Phase: The Eberlin Reaction

Abstract: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Cited by 86 publications

References 242 publications

Recognition and resolution of isomeric alkyl anilines by mass spectrometry

Recognition and resolution of isomeric alkyl anilines by mass spectrometry

Alternative reagents for chemical noise reduction in liquid chromatography-mass spectrometry using selective ion-molecule reactions

Charge-tagged ligands derived of 1,3-imidazolium ion as catalyst precursor of copper, nickel and palladium

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