Claisen rearrangement induced by low-energy collision of ESI-generated, protonated benzyloxy indoles.

Abstract

The Claisen rearrangement is a well-known process occurring in condensed phase. In the gas-phase protonated allyl phenyl ethers, propargyl phenyl ethers, and N-allyl aniline produced by positive ion chemical ionization undergo Claisen rearrangement. This reaction has been observed even in the case of odd-electron molecular ions. Phenyl allenyl ether molecular ions actually undergo Claisen rearrangement, producing intense [M - CO](+*) ions. In this investigation, the behavior of protonated benzyloxy indole and some of its derivatives, obtained in electrospray conditions, is described. Low-energy MS/MS experiments carried out on [M + H](+) species show CO loss and an unexpected water loss: both can be justified only by the occurrence of Claisen rearrangement. Deuterium labeling experiments confirm this mechanism. The influence of different substituents in the indole moiety is discussed.

Cite this paper

@article{Crotti2007ClaisenRI, title={Claisen rearrangement induced by low-energy collision of ESI-generated, protonated benzyloxy indoles.}, author={S Crotti and Laura Stella and Ilaria De Munari and Franco Massaccesi and Livius Cotarca and Massimiliano Forcato and Pietro Traldi}, journal={Journal of mass spectrometry : JMS}, year={2007}, volume={42 12}, pages={1562-8} }