Acylation of Hexaphenylbenzene for the Synthesis of [5]Cumulenes
Johnson MA, Martin M, Cocq K, Jux N, Ferguson MJ, Tykwinski RR (2022)
Publication Type: Journal article
Publication year: 2022
Journal
Abstract
The Friedel-Crafts acylation of hexaphenylbenzene is reported, and the reaction favorably provides the monoacylated products 1 a and 1 b. The resulting ketones 1 a and 1 b are used as precursors for the formation of [5]cumulenes, including 6 b in which the sterically demanding HPB moiety affords a diethynyl[5]cumulene that features significant stability (persistence) versus the analog 6 c which lacks the HPB endgroups. The unsymmetrical substitution pattern of the two most soluble derivatives 6 b and 6 c, allows for estimation of rotational barriers for diethynyl[5]cumulenes via VT NMR studies of cis-trans isomerization. For both molecules, the barrier to rotation is ca. 15 kcal mol−1, which is attenuated in comparison to other [5]cumulenes due to the presence of the ethynyl endgroups.
Authors with CRIS profile
Max Martin
Lehrstuhl für Organische Chemie II
Norbert Jux
Interdisziplinäres Zentrum für Molekulare Materialien
Involved external institutions
Canada (CA)How to cite
APA:
Johnson, M.A., Martin, M., Cocq, K., Jux, N., Ferguson, M.J., & Tykwinski, R.R. (2022). Acylation of Hexaphenylbenzene for the Synthesis of [5]Cumulenes. European Journal of Organic Chemistry. https://dx.doi.org/10.1002/ejoc.202101467
MLA:
Johnson, Matthew A., et al. "Acylation of Hexaphenylbenzene for the Synthesis of [5]Cumulenes." European Journal of Organic Chemistry (2022).
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