Facile Smiles-type rearrangement in radical cations of N-acyl arylsulfonamides and analogs.

ABSTRACT:

Rationale

N-Alkylation of sulfonylbenzamides was reported recently to cause a dramatic and surprising change in electron ionization mass spectrometry (EIMS), leading to a closed-shell base peak. Only an incomplete, speculative mechanism was available at that time. The fragmentation mechanism is determined in the present work and set in the context of related compounds.

Methods

Candidate reaction mechanisms were evaluated theoretically using modest density-functional calculations. The fragmentation mechanism with the lowest barriers was identified and one of its implications tested successfully by experimental (18) O-isotopic substitution.

Results

The amide oxygen atom attacks the arylsulfonyl group at the ipso position (Smiles-type rearrangement), displacing a molecul

SUBMITTER: Irikura KK 

PROVIDER: S-EPMC5096379 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature