Benzene’s forgotten isomer takes centre stage in organic synthesis

An overlooked benzene isomer could become a powerful and versatile reagent in organic synthesis. Researchers demonstrated that the high energy compound 1,2,3-cyclohexatriene readily participates in a diverse range of cycloaddition, nucleophilic addition and σ-bond insertion reactions, enabling chemists to construct complex molecular architectures in just a few steps.

Isomers of benzene have captured the imagination of organic chemists for decades and studies of unusual strained structures such as Dewar-benzene and prismane have proven pivotal to our understanding of resonance theory and aromaticity. High-energy relatives of benzene like benzyne and 1,2-cyclohexadiene have likewise attracted significant interest, their propensity to undergo strain-promoted reactions making them valuable synthetic intermediates.