Direct AzaDiels–Alder Reaction in Water Catalyzed by Layered αZirconium Hydrogen Phosphate and Sodium Dodecyl Sulfate

The direct azaDiels–Alder reaction between 2cyclohexen1one 1 and benzaldimines 2in water is reported for the first time. The reaction occurs at 30 °C, is catalyzed by layered αzirconium hydrogen phosphate αZrP and requires the presence of sodium dodecyl sulfate SDS. The reaction yield is excellent, the reaction is faster and the exodiastereoselectivity is higher than when organic solvent is used. The onepot, threecomponent version of the reaction and the recycling of both the catalyst and the aqueous mother liquor in toto water, αZrP and SDS have also been investigated. © WileyVCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009