Understanding anionic Chugaev elimination in pericyclic tetracene formation

Burroughs, Laurence, Ritchie, John and Woodward, Simon (2016) Understanding anionic Chugaev elimination in pericyclic tetracene formation. Tetrahedron, 72 (13). pp. 1686-1689. ISSN 0040-4020

Full text not available from this repository.


The reaction pathway for the formation of tetracenes from the diols 1,2-C6H4(CHOHC≡CAr)2 , LiHDMS, CS2 and MeI has been modelled by computational methods at the CBS-QB3 level of theory. Comparison of PhCHOC(=S)YCCPh (Y = S- or SMe) indicates a slight kinetic advantage for the anionic system towards [3,3]-sigmatropic rearrangement [Eact(calc.) 19.7 vs 21.8 kcal mol-1]. Using anthracene-based models, 10-{SC(=O)Y}-4a,10-dihydroanthracene (Y = S- or SMe), allows direct comparison of both syn and anti-manifolds in the neutral vs. anionic Chugaev elimination. Syn elimination of [HSC(=O)S]- is distinctly favoured [Eact(calc.) 11.4 kcal mol-1] vs. syn elimination of neutral methylated HSC(=O)SMe [Eact(calc.) 27.5 kcal mol-1]. The smaller barrier to syn elimination of the anionic leaving group is in accord with the low temperature conditions required for this Chugaev reaction (60 oC) and suggests a general advantage in carrying out Chugaev eliminations in anionic manifolds.

Item Type: Article
RIS ID: https://nottingham-repository.worktribe.com/output/778269
Schools/Departments: University of Nottingham, UK > Faculty of Science > School of Chemistry
Identification Number: https://doi.org/10.1016/j.tet.2016.02.025
Depositing User: Bramwell, Roseanna
Date Deposited: 10 Feb 2016 09:35
Last Modified: 04 May 2020 17:39
URI: https://eprints.nottingham.ac.uk/id/eprint/31578

Actions (Archive Staff Only)

Edit View Edit View