Copper zeolites as green catalysts for multicomponent reactions of aldehydes, terminal alkynes and amines: An efficient and green synthesis of propargylamines

Cu-I-modified zeolites, especially Cu-I-USY, have proved to be very efficient catalysts in multicomponent reactions, allowing for a solvent-free synthesis of propargylamines from aldehydes, amines, and terminal alkynes. With a heterogeneous catalyst and in the absence of solvent, this process is among the greenest ever reported. A mechanism has been proposed for this three-component reaction. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008.