The aza-Diels-Alder reaction between benzaldimines 1 and Danishefsky's diene in solvent-free conditions is reported for the first time. The reaction occurs rapidly at 30 degrees C and is catalyzed by porous alpha-zirconium hydrogen phosphate (p-alpha ZrP) in the presence of sodium dodecyl sulfate (SDS). The yields were excellent. The recycling of the catalyst has also been investigated. (C) 2009 Elsevier B.V. All rights reserved.