Green and Facile Synthesis of 4H-Pyran Scaffold Catalyzed by Pure Nano-Ordered Periodic Mesoporous Organosilica with Isocyanurate Framework (PMO-ICS)

Isocyanurate bridging (PMO-ICS) microporous, without any post-modification using Bronsted and Lewis acid or base centers, was used as a highly active and recyclable bifunctional nano-ordered catalyst for three-component synthesis of diverse 4H-pyran derivatives from enolizable compounds, different aldehydes and malononitrile under mild reaction conditions in good to excellent yields and short reaction times. Furthermore, the PMO-ICS catalyst was also recovered and reused at least five times without significant loss of its catalytic activity. Elimination of any toxic heavy metals or corrosive reagents for modification of the catalytic activity, low loading of the catalyst, high to excellent yields, easy separation and purification of the products, and reusability of the catalyst are among significant advantages of this green protocol.