title: Dissociation of protonated N-(3-phenyl-2H-chromen-2-ylidene)-benzenesulfonamide in the gas phase: cyclization via sulfonyl cation transfer.
abstract: BACKGROUND
  In the tandem mass spectrometry of protonated N-(3-phenyl-2H-chromen-2-ylidene)benzenesulfonamides, the precursor ions have been observed to undergo gas-phase dissociation via two competing channels: (a) the predominant channel involves migration of the sulfonyl cation to the phenyl C atom and the subsequent loss of benzenesulfinic acid along with cyclization reaction, and (b) the minor one involves dissociation of the precursor ion to give an ion/neutral complex of [sulfonyl cation/imine], followed by decomposition to afford sulfonyl cation or the INC-mediated electron transfer to give an imine radical cation.
  
  
  METHODS
  The proposed reaction channels have been supported by theoretical calculations and D-labeling experiments.
  
  
  RESULTS
  The gas-phase cyclization reaction originating from the N- to C-sulfonyl cation transfer has been first reported to the best of our knowledge.
  
  
  CONCLUSIONS
  For the substituted sulfonamides, the presence of electron-donating groups (R(2) -) at the C-ring effectively facilitates the reaction channel of cyclization reaction, whereas that of electron-withdrawing groups inhibits 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.affiliation: Key Laboratory of Organosilicon Chemistry and Material Technology, Hangzhou Normal University, Hangzhou, 311121, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Dong
authors.affiliation: Key Laboratory of Organosilicon Chemistry and Material Technology, Hangzhou Normal University, Hangzhou, 311121, China.
authors.forename: Lian
authors.initials: L
authors.lastname: Yu
authors.affiliation: Cancer Institute, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Guo
authors.affiliation: Key Laboratory of Organosilicon Chemistry and Material Technology, Hangzhou Normal University, Hangzhou, 311121, China.
authors.forename: Kezhi
authors.initials: K
authors.lastname: Jiang
mesh_terms: D002412:Cations / Q000032:analysis / Q000737:chemistry*; D003500:Cyclization; D005740:Gases / Q000737:chemistry*; D011522:Protons; D021241:Spectrometry, Mass, Electrospray Ionization; D013449:Sulfonamides / Q000032:analysis / Q000737:chemistry*; D013450:Sulfones / Q000737:chemistry*; D000096926:Benzenesulfonamides
chemical_list: D002412:Cations; D005740:Gases; D011522:Protons; D013449:Sulfonamides; D013450:Sulfones; D000096926:Benzenesulfonamides