Gas-phase polar [4(+)+2] cycloaddition of cationic 2-azabutadienes with enol ethers

dc.creatorMeurer, EC
dc.creatorEberlin, MN
dc.date2001
dc.dateOCT 1
dc.date2014-11-13T17:23:25Z
dc.date2015-11-26T17:10:42Z
dc.date2014-11-13T17:23:25Z
dc.date2015-11-26T17:10:42Z
dc.date.accessioned2018-03-28T23:59:15Z
dc.date.available2018-03-28T23:59:15Z
dc.identifierInternational Journal Of Mass Spectrometry. Elsevier Science Bv, v. 210, n. 41699, n. 469, n. 482, 2001.
dc.identifier1387-3806
dc.identifierWOS:000171742700041
dc.identifier10.1016/S1387-3806(01)00422-5
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/67797
dc.identifierhttp://www.repositorio.unicamp.br/handle/REPOSIP/67797
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/67797
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1280925
dc.descriptionPolar [4(+)+2] cycloaddition of the prototype cationic 2-azabutadiene with ethyl vinyl ether was recently reported, and its potential application for the structural analysis of enol ethers suggested [R. Augusti, F.C. Gozzo, L.A.B. Moraes, R. Sparrapan, M.N. Eberlin, J. Org. Chem. 63 (1998) 4889]. We now report that the gaseous N-methyl 2-azabutadienyl cation (MAB(+)) reacts similarly, readily and generally with alkyl, silyl, and thio-enol ethers. The intact cycloadducts are formed abundantly, and collision-induced dissociation of acyclic enol ether cycloadducts occurs competitively by RDA and by the characteristic loss of either a ROH, (CH3)(3)SiOH, or RSH neutral molecule. Cycloadducts of acyclic enol ethers that bear no double bond substituents also form upon RO(S)H loss a characteristic fragment of m/z 96. For the cycloadducts of enol ethers bearing double-bound substituents (R-1), the RO(S)H loss fragment displays a mass shift that corresponds to the mass of R-1. Endocyclic enol ethers also react readily by MAB(+) cycloaddition, but unless affected by ring substituents, the dissociation of their cycloadducts is dominated by RDA. Detailed structural information of the reactant enol ethers is therefore provided, and positional isomers are easily distinguished. Gas-phase polar [4(+)+2] cycloaddition with cationic 2-azabutadienes, as demonstrated here for MAB(+), is therefore class-selective and structurally diagnostic for enol ethers and their analogs. (C) 2001 Elsevier Science B.V.
dc.description210
dc.description41699
dc.descriptionSI
dc.description469
dc.description482
dc.languageen
dc.publisherElsevier Science Bv
dc.publisherAmsterdam
dc.publisherHolanda
dc.relationInternational Journal Of Mass Spectrometry
dc.relationInt. J. Mass Spectrom.
dc.rightsfechado
dc.rightshttp://www.elsevier.com/about/open-access/open-access-policies/article-posting-policy
dc.sourceWeb of Science
dc.subjection-molecule reactions
dc.subjectcationic azabutadienes
dc.subjectcycloaddition reactions
dc.subjectenol ethers
dc.subjectpentaquadrupole mass spectrometry
dc.subjectiminium ions
dc.subjectimmonium ions
dc.subjectC4H8N+
dc.subjectIon-molecule Reactions
dc.subjectIonization Mass-spectrometry
dc.subject1,3-butadiene Radical-cation
dc.subjectDiels-alder Cycloaddition
dc.subjectPotential-energy Surface
dc.subjectAcylium Ions
dc.subjectCyclotron-resonance
dc.subjectActivated Dissociation
dc.subjectIon/molecule Reactions
dc.subjectPhosphonium Ions
dc.titleGas-phase polar [4(+)+2] cycloaddition of cationic 2-azabutadienes with enol ethers
dc.typeArtículos de revistas


Este ítem pertenece a la siguiente institución