A Diels–Alder reaction catalyzed by eutectic complexes autogenously formed from solid state phenols and quinones

A Diels–Alder reaction starting from a stoichiometric solid mixture of dimethylanthracene (DMA) and p-benzoquinone (BQ) was efficiently catalyzed by adding a small amount of phenol derivatives via autogenous formation of eutectic complexes. The main mechanisms for the formation of eutectic complex with hydrogen bonds were the interposition of the charge transfer from a phenol to a quinone under the influence of steric hindrance by alkyl groups introduced into phenols.