Serendipitous Discovery of Dearomatized Dimers in Anthracene Derivative Oxidation.

We present the serendipitous discovery of an unusual dimer formed from anthracene-derived polyarenes. Unlike the typical oxidative coupling of substituted aromatic scaffolds, the reaction yielded a dearomatized enone dimer as the sole product. This dearomatized motif, notably, does not undergo the commonly observed rearomatization, and no biaryl products were detected. The anthracene dimers were produced in excellent yields. Structural validation via single-crystal X-ray analysis revealed that the dimers feature an sp-sp carbon-carbon bond connecting two α,β-unsaturated enones, existing as a pair of diastereomers. These unique dimers underscore the critical role of serendipity in advancing organic synthesis.