A mild, selective and efficient Nazarov cyclization of divinyl ketones catalyzed by phosphomolybdic acid (PMA) is described. The process demonstrates a broad substrate scope with functional group tolerance under short reaction times. PMA supported on silicagel is more efficient than the bulk catalyst and is recycled up to three times without significant activity loss.
AbstractDifferent in water! We have developed Nazarov‐type reactions in water. Different reaction courses compared with those in organic solvents are observed in water. In the presence of a scandium based, surfactant‐type catalyst, water‐trapping products are obtained exclusively. The results presented are unprecedented and provide a valuable extension to information available regarding organic reactions in water.magnified image