title: Gas-Phase Fragmentation of Protonated N,2-Diphenyl-N'-(p-Toluenesulfonyl)Ethanimidamides: Tosyl Cation Transfer Versus Proton Transfer.
abstract: The gas-phase dissociation chemistry of protonated N,2-diphenyl-N'-(p-toluenesulfonyl) ethanimidamides was investigated by electrospray ionization mass spectrometry in combination with density functional theory calculation. The protonated molecules underwent fragmentation via two main competing channels: (1) migration of the tosyl cation to the anilinic N atom and the subsequent loss of 2-phenylacetonitrile to afford protonated N-phenyl p-toluenesulfonamide (m/z 248); and (2) transfer of the ionizing proton to the anilinic N atom to give an ion/neutral complex of [tosyl cation / 2-phenylacetonitrile] (m/z 272) and the subsequent decomposition to yield tosyl cation (m/z 155). To the best of our knowledge, the gas-phase tosyl cation transfer has not been reported previously. For the para-substituted sulfonamides, the presence of electron-donating groups on the anilinic ring inhibits the reaction channel of the tosyl cation migration, whereas the presence of electron-withdrawing groups favors this pathway.
authors.affiliation: Key Laboratory of Organosilicon Chemistry and Material Technology, Hangzhou Normal University, Hangzhou, 311121, China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Wang
authors.forename: Lian
authors.initials: L
authors.lastname: Yu
authors.forename: Yanqing
authors.initials: Y
authors.lastname: Wu
authors.forename: Cheng
authors.initials: C
authors.lastname: Guo
authors.forename: Ningwen
authors.initials: N
authors.lastname: Zhang
authors.forename: Kezhi
authors.initials: K
authors.lastname: Jiang
mesh_terms: D000577:Amides / Q000737:chemistry*; D002412:Cations / Q000737:chemistry*; D005740:Gases / Q000737:chemistry*; D013058:Mass Spectrometry; D011522:Protons; D014105:Tosyl Compounds / Q000737:chemistry*
chemical_list: D000577:Amides; D002412:Cations; D005740:Gases; D011522:Protons; D014105:Tosyl Compounds