Gas-Phase Intramolecular Cyclization of Argentinated N-Allylbenzamides

Abstract

Abstract. The fragmentations of argentinated N-allylbenzamides have been exhaustively studied through collision-induced dissociation and through deuterium labeling. The intriguing elimination of AgOH is certified as the consequence of intramolecular cyclization between terminal olefin and carbonyl carbon following proton transfer to carbonyl oxygen, rather than simple enolization of amide. Linear free energy correlations and density functional theory (DFT) calculations were performed to understand the competitive relationship between AgOH loss and AgH loss, which results from the 1,2-elimination of α-hydrogen (to the amido nitrogen) with the silver.

Even‐electron [M–H]+ ions generated by loss of AgH from argentinated peptides with N‐terminal imine groups

“…Experiments show (a) formation of novel even‐electron peptide cations by CID and (b) the extent to which sequence ions (conventional b , a and y ions) are generated from peptides with fixed charge site and thus lacking a conventional mobile proton. We note that [M–H] + ion formation as a result of elimination of AgH has been reported for CID of Ag(I) complexes with 2‐aminoanilide and benzimidazole, and argeninated N ‐allylbenzamides . For these systems, interesting fragmentation cascades were also observed.…”

“…We note that [M-H] + ion formation as a result of elimination of AgH has been reported for CID of Ag(I) complexes with 2-aminoanilide and benzimidazole, [53] and argeninated N-allylbenzamides. [54] For these systems, interesting fragmentation cascades were also observed.…”