Abstract

The origin of the stereoselectivity in the lithiation/trapping of 2-alkylideneaziridines bearing a chiral group as the nitrogen substituent was investigated. Optimal reaction conditions were discovered by in situ FT-IR monitoring. In addition, it has been found that the solvent and the alkene substitution pattern are important factors able to impart a switch in stereoselectivity. While lithiation of the alkylideneaziridine ring flanked by either a fully substituted or a Z-configured alkene pendant occurs stereoselectively in THF, in contrast unsubstituted 2-methyleneaziridine undergoes lithiation in toluene with the opposite sense of stereoinduction. Lithiation experiments, on deuterium labelled 2-alkylideneaziridines, confirmed the configurational stability of the lithiated intermediates. A model based on complexation and proximity effects was proposed to rationalize the reactivity. This model assumes that slowly equilibrating N-invertomers undergo deprotonation (lithiation) at different rates and that the stereochemical outcome is established during the deprotonation step.

Autore Pugliese

• Degennaro Leonardo , Luisi Renzo

Tutti gli autori

• DEGENNARO L.;LUISI R.

Titolo volume/Rivista

Non Disponibile

Anno di pubblicazione

2014

ISSN

1477-0520

ISBN

Non Disponibile

Numero di citazioni Wos

11

Ultimo Aggiornamento Citazioni

Non Disponibile

Numero di citazioni Scopus

10

Ultimo Aggiornamento Citazioni

Non Disponibile

Settori ERC

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Codici ASJC

Non Disponibile