A green and efficient amine-functionalized ionic liquid/H2O catalytic system for the synthesis of α,α′-bis(substituted benzylidene)cyclopentanones

An environmentally benign and convenient amine-functionalized ionic liquid (IL) catalytic system was explored for the preparation of α,α′-bis(substituted benzylidene)cyclopentanones by the cross-aldol condensation of aromatic aldehydes with cyclopentanone. High yields were obtained without using any organic solvents. The condensation products can be separated easily and the ILs can be recovered and reused at least five times without apparently loss of activity. The potential mechanism of the cross-aldol condensation reaction in this IL catalytic system is discussed.