Concomitant hydride and proton transfer: an essay on competing and consecutive key reactions occurring in gaseous ion/neutral complexes

Kuck D (2012)
European Journal of Mass Spectrometry 18(2): 161-181.

Download
Es wurde kein Volltext hochgeladen. Nur Publikationsnachweis!
Zeitschriftenaufsatz | Veröffentlicht | Englisch
Abstract / Bemerkung
The interplay of proton transfer and hydride transfer reactions in alkylbenzenium ions and related protonated di- and oligophenylalkanes is presented and discussed. While intra- and inter-annular proton exchange has been recognised to be a ubiquitous feature in protonated arenes, hydride abstraction is much less obvious but can become a dominating fragmentation channel in metastable ions of tert-butyl-substituted alkylbenzenium ions and related carbocations. In such cases, proton-induced release of the tert-butyl cation gives rise to ion/neutral complexes as reactive intermediates, for example, [(CH3)(3)C+center dot center dot center dot arylCH(2)(alpha)(CH2)(n) CH(2)(omega)aryl'] with n >= 0 and highly regioselective intra-complex hydride transfer occurs from all of the benzylic methylene hydride ion donor groups (alpha-CH2 and (omega)-CH2) to the tert-butyl cation acting as a Lewis acid. Substituent effects on the individual contributions to the overall hydride transfer from different donor sites, including ortho-methyl groups, in particular, and the concomitant intra-complex proton transfer from the tert-butyl cation to the neutral diarylalkane constituent corroborate the view of "bisolvated" complexes as the central intermediates, in which the carbenium ion is coordinated to both of the aromatic pi-electron systems. The role of cyclisation processes, converting the benzylic [M-H](+)-type ions into the isomeric benzenium, [M+H](+)-type ions prior to fragmentation, is demonstrated for several cases. This overall scenario, consisting of consecutive and/or competing intra-complex hydride abstraction and proton transfer, intra-annular proton shifts (H+ ring walk) and inter-annular proton transfer, hydrogen exchange ("scrambling") processes, and cyclisation and other electrophilic substitution reactions, is of general importance in this field of gas-phase ion chemistry and more recent examples concerning protonated ethers, benzylpyridinium and benzylammmonium ions are discussed in which these recurring features play central and concerted mechanistic roles as well.
Erscheinungsjahr
Zeitschriftentitel
European Journal of Mass Spectrometry
Band
18
Zeitschriftennummer
2
Seite
161-181
ISSN
PUB-ID

Zitieren

Kuck D. Concomitant hydride and proton transfer: an essay on competing and consecutive key reactions occurring in gaseous ion/neutral complexes. European Journal of Mass Spectrometry. 2012;18(2):161-181.
Kuck, D. (2012). Concomitant hydride and proton transfer: an essay on competing and consecutive key reactions occurring in gaseous ion/neutral complexes. European Journal of Mass Spectrometry, 18(2), 161-181. doi:10.1255/ejms.1171
Kuck, D. (2012). Concomitant hydride and proton transfer: an essay on competing and consecutive key reactions occurring in gaseous ion/neutral complexes. European Journal of Mass Spectrometry 18, 161-181.
Kuck, D., 2012. Concomitant hydride and proton transfer: an essay on competing and consecutive key reactions occurring in gaseous ion/neutral complexes. European Journal of Mass Spectrometry, 18(2), p 161-181.
D. Kuck, “Concomitant hydride and proton transfer: an essay on competing and consecutive key reactions occurring in gaseous ion/neutral complexes”, European Journal of Mass Spectrometry, vol. 18, 2012, pp. 161-181.
Kuck, D.: Concomitant hydride and proton transfer: an essay on competing and consecutive key reactions occurring in gaseous ion/neutral complexes. European Journal of Mass Spectrometry. 18, 161-181 (2012).
Kuck, Dietmar. “Concomitant hydride and proton transfer: an essay on competing and consecutive key reactions occurring in gaseous ion/neutral complexes”. European Journal of Mass Spectrometry 18.2 (2012): 161-181.

10 Zitationen in Europe PMC

Daten bereitgestellt von Europe PubMed Central.

Intramolecular Halogen Transfer via Halonium Ion Intermediates in the Gas Phase.
Chai Y, Xiong X, Yue L, Jiang Y, Pan Y, Fang X., J Am Soc Mass Spectrom 27(1), 2016
PMID: 26383734
Elimination of benzene from protonated N-benzylindoline: benzyl cation/proton transfer or direct proton transfer?
Guo C, Yue L, Guo M, Jiang K, Pan Y., J Am Soc Mass Spectrom 24(3), 2013
PMID: 23361371

Export

Markieren/ Markierung löschen
Markierte Publikationen

Open Data PUB

Web of Science

Dieser Datensatz im Web of Science®

Quellen

PMID: 22641718
PubMed | Europe PMC

Suchen in

Google Scholar