Skip to Main content Skip to Navigation
Journal articles

First Direct Evidence of an ortho -Lithiated Aryloxetane: Solid and Solution Structure, and Dynamics

Abstract : Oxetanes are key synthons for asymmetric synthesis and also effective in directing ortho‐lithiation. This work first reports the solution and the solid‐state structure of an ortho‐lithiated aryloxetane (1‐Li) in the presence/absence of a bidentate ligand such as N,N,N′,N′‐tetramethylethylenediamine (TMEDA). Single crystal X‐ray diffraction analysis of 1‐Li revealed a singular crystallographic structure in which the asymmetric unit comprises a core where the lithium atom is coordinated to the nitrogen atom of half a molecule of TMEDA and intramolecularly stabilised by the oxetane ring oxygen. This aggregation state is unprecedented in ortho‐lithiated arenes. Variable temperatures multinuclear magnetic resonance (1H, 7Li, 13C) mono‐ and two‐dimensional NMR studies and DFT computations supported the coexistence in solution of three chelated bridged dimeric aggregates, in slow equilibration at 180 K. The major isomer is an heterochiral aggregate on the basis of 1H,7Li‐HOESY and 1H,1H‐NOESY experiments. Conclusions were supported by the preparation of enantiomerically enriched (S)‐1‐Li. The privileged formation of homochiral aggregates from racemic mixtures may also have implications for the development of chiral resolution processes.
Document type :
Journal articles
Complete list of metadata
Contributor : Madeleine ROUX-MERLIN Connect in order to contact the contributor
Submitted on : Monday, September 23, 2019 - 8:36:16 AM
Last modification on : Sunday, June 26, 2022 - 2:40:50 AM



Filippo Perna, Aurelia Falcicchio, Antonio Salomone, Anne Milet, Rosanna Rizzi, et al.. First Direct Evidence of an ortho -Lithiated Aryloxetane: Solid and Solution Structure, and Dynamics. European Journal of Organic Chemistry, Wiley-VCH Verlag, 2019, 2019 (31-32), pp.5549-5556. ⟨10.1002/ejoc.201900949⟩. ⟨hal-02294014⟩



Record views