AgOTf-catalyzed aza-Diels-Alder reactions of Danishefsky's diene with imines in water

Aza-Diels-Alder reactions of Danishefsky's diene with imines in water took place smoothly in the presence of a catalytic amount of silver triflate to afford dihydro-4-pyridones in high yields. The silver triflate-catalyzed three-component reactions starting from aldehydes, amines, and Danishefsky's diene were also performed efficiently. In the three-component reactions with benzaldehyde, the addition of a non-ionic surfactant was found to be effective.