One‐Step Synthesis of Functionalized Triptycene‐quinones as Acceptors for Electron‐Transfer Compounds

Abstract

AbstractThe synthesis of appropriate porphyrin‐quinone electron‐transfer complexes as model compounds for photosynthesis requires access to functionalized triptycene quinone aldehydes with different redox potentials. A synthetic strategy involving a classical Diels‐Alder reaction, tautomerization and oxidation was only of limited utility for preparing the desired compounds. Thus, an alternative approach was required and for this purpose a strategy involving the reaction of excess quinone with appropriate anthracene derivatives in acetic acid has been developed. This method affords the target compounds in a single synthetic step in good yields and with high purity. The aldehyde functionality required for the subsequent porphyrin synthesis can be incorporated into either the anthracene or the quinone starting component. Fifteen different triptycene quinones have been synthesized, eight of which have been studied in detail by single crystal X‐ray crystallography to provide insight into their structural chemistry and solid‐state aggregation properties. Additionally, the synthesis of two porphyrin‐quinone target compounds is described.