Efficient synthesis of xanthene derivatives in aqueous media in the presence of Cu-anchored furfural imine-functionalized halloysite

A novel hybrid catalyst based on grafting Cu on furfural imine-functionalized halloysite was designed, characterized and used for promoting synthesis of xanthene derivatives via three- component reaction of benzaldehyde derivatives, dimedone, and β-naphthol in aqueous media and under mild reaction condition. The results established high catalytic activity of the hybrid system, which was superior to some conventional catalysts. Moreover, the catalyst was reusable and could be easily recovered and reused for several reaction runs with slight loss of catalytic activity. Broad substrate scope, simple work up procedure and performing the process in aqueous media are other merits of this protocol.