A new antiaromatic compound: 1,4-biphenylenequinone synthesis and trapping reactions

Abstract

This study reports the first successful generation of 1,4-biphenylenequinone, a highly reactive compound predicted to exhibit antiaromatic character but not previously synthesized experimentally. The authors developed a synthetic route to produce the target molecule and investigated its reactivity through dimerization and trapping experiments with various dienes. The results demonstrate that 1,4-biphenylenequinone readily undergoes intermolecular reactions, forming dimers and cycloaddition products, while remaining resistant to decomposition or structural rearrangement. Semiempirical AM1 calculations further indicate that the compound is significantly less stable than its 2,3-isomer and retains structural features consistent with antiaromaticity. The study provides the first experimental evidence for the behavior of 1,4-biphenylenequinone and establishes a foundation for future spectroscopic investigations of its antiaromatic properties.