Application of Chlorophyll Extracted from Spinach as a Green and affordable Catalyst for the Synthesis of Tetrahydrobenzo[b]pyran and Pyrano[c]chromene

Chlorophyll is a natural pigment used for the synthesis of organic substances for instance sugars. At mild conditions, chlorophyll was employed as a green catalyst for the synthesis of tetrahydrobenzo[b]pyran and 3,4-dihydropyrano[c]chromene from the condensation between aromatic aldehydes, malononitrile, and 4-hydroxy-2H-chromen-2-one is an active enolic compound. This methodology has a considerable number of advantages such as mild conditions, natural, affordable catalyst, excellent yields, eco-friendly and, short reaction time. Another point worth mentioning is that purification of the products does not require sophisticated methods like column chromatography.