Cellulose-Supported Metal Nanocomposite as a Green and Reusable Catalyst for One-Pot Multicomponent Synthesis of 2-Amino-4H-Chromene Derivatives

Nanoparticles, especially coated or supported magnetic metal part, have emerged as a new class of nanocatalyst. Simple separation of them using an external magnetic field without any filtration is one of the main features for using this type of catalyst. These catalysts showed both high catalytic activity and high degree of chemical stability in various organic solvents.Multi-component reaction (MCRs) has offered many fascinating and challenging transformation in organic synthesis. The atom-economy, convergent character, operational simplicity, structural diversity, and complexity of the molecules are the major advantages associated with multi-component reactions. Besides this multi-component reactions are emerging as a powerful tool in the synthesis of biologically important compounds.Among the heterocycles, functionally substituted 4H-chromenes have received considerable attention in the field of medicinal chemistry because of their wide range of useful biological properties, which include spasmolytic, diuretic, anticoagulant and anticancer activity. Because of their importance, the methods for their synthesis have become a focus of synthetic organic chemist.In continuation of our interest in the application of nanocatalysts in organic synthesis, cellulose -supported metal nanocomposite used as a catalyst for the one-pot and three component synthesis of different 2-amino-4H-chromene derivatives in good to excellent yield under mild conditions. A good correlation between the amount of surface acid sites as well as the surface morphology of the catalysts and the catalytic activity has been observed. This method has been found to be simple and economical, because the solid support could be recycled and reused without significant loss of its catalytic activity.