Ag nanoparticles in hollow magnetic mesoporous spheres: A highly efficient and magnetically separable catalyst for synthesis of β-enaminones

A nanoreactor (Ag/HMMS) composed of hollow magnetic mesoporous spheres (HMMS) and Ag nanoparticles was found to be an efficient catalyst for synthesis of β-enamino ketones or esters from β-dicarbonyl compound under mild reaction conditions. The novel catalyst could be easily recovered by an external magnet from the reaction mixture and recycled five times without any significant loss in activity.