Microwave-assisted synthesis of 1,5-dioxo-3-substituted [5]ferrocenophanes

The Claisen–Schmidt reaction between 1,1′-diacetylferrocene and ferrocenecarboxaldehyde under microwave irradiation has been investigated in different conditions. The selective synthesis of 1,5-dioxo-3-ferrocenyl[5]ferrocenophane has been achieved and a simple protocol for its purification was established. The reaction was generally applicable to other non-enolizable aldehydes and the corresponding 1,5-dioxo-3-substituted [5]ferrocenophanes were obtained in high yield within 30 min.