A Mini-review on Recent Advances in Synthesis of Dihydropyrano [3, 2-c] chromenes Using Magnetic Nanocatalysts.

The development of an active, selective, and long-term selective catalyst for the synthesis of biologically active heterocycles is still challenging. However, magnetic nanocatalysts have divergent applications like high efficiency, selectivity, consumption, and reusability. The current review explores a detailed survey of the latest information on synthetic methods of Pyrano [3, 2-c] chromene derivatives using different magnetic nanocatalysts. Numerous studies on the synthesis of these practical compounds have been stimulated by the special qualities and wide-ranging applications of pyrano coumarins and the nanoparticles were tested for their catalytic effectiveness in a one-pot, three-component reaction involving aldehydes, malononitrile, and 4-hydroxycoumarin for the manufacturing of dihydropyrano [3, 2-c] chromenes (coumarins).