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Gas phase retro-Michael reaction resulting from dissociative protonation: fragmentation of protonated warfarin in mass spectrometry.
J Mass Spectrom. 2012 Aug; 47(8):1059-64.JM

Abstract

A mass spectrometric study of protonated warfarin and its derivatives (compounds 1 to 5) has been performed. Losses of a substituted benzylideneacetone and a 4-hydroxycoumarin have been observed as a result of retro-Michael reaction. The added proton is initially localized between the two carbonyl oxygens through hydrogen bonding in the most thermodynamically favorable tautomer. Upon collisional activation, the added proton migrates to the C-3 of 4-hydroxycoumarin, which is called the dissociative protonation site, leading to the formation of the intermediate ion-neutral complex (INC). Within the INC, further proton transfer gives rise to a proton-bound complex. The cleavage of one hydrogen bond of the proton-bound complex produces the protonated 4-hydroxycoumarin, while the separation of the other hydrogen bond gives rise to the protonated benzylideneacetone. Theoretical calculations indicate that the 1, 5-proton transfer pathway is most thermodynamically favorable and support the existence of the INC. Both substituent effect and the kinetic method were utilized for explaining the relative abundances of protonated 4-hydroxycoumarin and protonated benzylideneacetone derivative. For monosubstituted warfarins, the electron-donating substituents favor the generation of protonated substituted benzylideneacetone, whereas the electron-withdrawing groups favor the formation of protonated 4-hydroxycoumarin.

Authors+Show Affiliations

Department of Chemistry, Zhejiang University, Hangzhou, 310027, China.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22899515

Citation

Zhang, Jia, et al. "Gas Phase retro-Michael Reaction Resulting From Dissociative Protonation: Fragmentation of Protonated Warfarin in Mass Spectrometry." Journal of Mass Spectrometry : JMS, vol. 47, no. 8, 2012, pp. 1059-64.
Zhang J, Chai Y, Jiang K, et al. Gas phase retro-Michael reaction resulting from dissociative protonation: fragmentation of protonated warfarin in mass spectrometry. J Mass Spectrom. 2012;47(8):1059-64.
Zhang, J., Chai, Y., Jiang, K., Yang, H., Pan, Y., & Sun, C. (2012). Gas phase retro-Michael reaction resulting from dissociative protonation: fragmentation of protonated warfarin in mass spectrometry. Journal of Mass Spectrometry : JMS, 47(8), 1059-64. https://doi.org/10.1002/jms.3055
Zhang J, et al. Gas Phase retro-Michael Reaction Resulting From Dissociative Protonation: Fragmentation of Protonated Warfarin in Mass Spectrometry. J Mass Spectrom. 2012;47(8):1059-64. PubMed PMID: 22899515.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Gas phase retro-Michael reaction resulting from dissociative protonation: fragmentation of protonated warfarin in mass spectrometry. AU - Zhang,Jia, AU - Chai,Yunfeng, AU - Jiang,Kezhi, AU - Yang,Huameng, AU - Pan,Yuanjiang, AU - Sun,Cuirong, PY - 2012/8/18/entrez PY - 2012/8/18/pubmed PY - 2012/12/10/medline SP - 1059 EP - 64 JF - Journal of mass spectrometry : JMS JO - J Mass Spectrom VL - 47 IS - 8 N2 - A mass spectrometric study of protonated warfarin and its derivatives (compounds 1 to 5) has been performed. Losses of a substituted benzylideneacetone and a 4-hydroxycoumarin have been observed as a result of retro-Michael reaction. The added proton is initially localized between the two carbonyl oxygens through hydrogen bonding in the most thermodynamically favorable tautomer. Upon collisional activation, the added proton migrates to the C-3 of 4-hydroxycoumarin, which is called the dissociative protonation site, leading to the formation of the intermediate ion-neutral complex (INC). Within the INC, further proton transfer gives rise to a proton-bound complex. The cleavage of one hydrogen bond of the proton-bound complex produces the protonated 4-hydroxycoumarin, while the separation of the other hydrogen bond gives rise to the protonated benzylideneacetone. Theoretical calculations indicate that the 1, 5-proton transfer pathway is most thermodynamically favorable and support the existence of the INC. Both substituent effect and the kinetic method were utilized for explaining the relative abundances of protonated 4-hydroxycoumarin and protonated benzylideneacetone derivative. For monosubstituted warfarins, the electron-donating substituents favor the generation of protonated substituted benzylideneacetone, whereas the electron-withdrawing groups favor the formation of protonated 4-hydroxycoumarin. SN - 1096-9888 UR - https://www.unboundmedicine.com/medline/citation/22899515/Gas_phase_retro_Michael_reaction_resulting_from_dissociative_protonation:_fragmentation_of_protonated_warfarin_in_mass_spectrometry_ L2 - https://doi.org/10.1002/jms.3055 DB - PRIME DP - Unbound Medicine ER -