1,2,3-Cyclohexatriene Explained

1,2,3-Cyclohexatriene is an unstable chemical compound with the molecular formula .^[1] It is an unusual isomer of benzene in which the three double bonds are cumulated.

This highly strained compound was first prepared in 1990, by reacting a cyclohexadiene derivative with cesium fluoride.^[2] The product was too reactive to be isolated on its own, so its existence was confirmed by trapping via a cycloaddition reaction.

1,2,3-Cyclohexatriene and its derivatives undergo a variety of reactions including cycloadditions, nucleophilic additions, and σ-bond insertions,^[3] and therefore they can be versatile reagents for organic synthesis.^[4]

Notes and References

1. News: Benzene's forgotten isomer takes centre stage in organic synthesis . May 2, 2023 .
2. 10.1021/ja00179a050 . 1,2,3-cyclohexatriene and cyclohexen-3-yne: Two new highly strained C6H6 isomers . 1990 . Shakespeare . William C. . Johnson . Richard P. . Journal of the American Chemical Society . 112 . 23 . 8578–8579 .
3. 10.1038/s41586-023-06075-8 . Strain-promoted reactions of 1,2,3-cyclohexatriene and its derivatives . 2023 . Kelleghan . Andrew V. . Bulger . Ana S. . Witkowski . Dominick C. . Garg . Neil K. . Nature . 618 . 7966 . 748–754 . 37075803 . 10460091 . 2023Natur.618..748K . 258237506 .
4. Web site: A fresh look at 1,2,3-cyclohexatriene shows it could be used as a versatile reagent in organic synthesis . May 3, 2023 .