Novel magnetic propylsulfonic acid-anchored isocyanurate-based periodic mesoporous organosilica (Iron oxide@PMO-ICS-PrSO3H) as a highly efficient and reusable nanoreactor for the sustainable synthesis of imidazopyrimidine derivatives.

In this study, preparation and characterization of a new magnetic propylsulfonic acid-anchored isocyanurate bridging periodic mesoporous organosilica (Iron oxide@PMO-ICS-PrSO3H) is described. The iron oxide@PMO-ICS-PrSO3H nanomaterials were characterized by Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy and field emission scanning electron microscopy as well as thermogravimetric analysis, N2 adsorption-desorption isotherms and vibrating sample magnetometer techniques. Indeed, the new obtained materials are the first example of the magnetic thermally stable isocyanurate-based mesoporous organosilica solid acid. Furthermore, the catalytic activity of the Iron oxide@PMO-ICS-PrSO3H nanomaterials, as a novel and highly efficient recoverable nanoreactor, was investigated for the sustainable heteroannulation synthesis of imidazopyrimidine derivatives through the Traube-Schwarz multicomponent reaction of 2-aminobenzoimidazole, C‒H acids and diverse aromatic aldehydes. The advantages of this green protocol are low catalyst loading, high to quantitative yields, short reaction times and the catalyst recyclability for at least four consecutive runs.

Propylsulfonic acid-anchored isocyanurate-based periodic mesoporous organosilica (PMO-ICS-Pr-SO3H): A new and highly efficient recoverable nanoporous catalyst for the one-pot synthesis of bis(indolyl)methane derivatives.

A new propylsulfonic acid-anchored isocyanurate bridging periodic mesoporous organosilica (PMO-ICS-Pr-SO3H) was prepared and shown to be a highly efficient recyclable nanoporous catalyst for the one-pot synthesis of bis(indolyl)methane derivatives in good to excellent yields from indole and different aldehydes in EtOH under mild reaction conditions in short reaction times. Moreover, the nanoporous catalyst was recovered and reused at least four times without significant decrease in its catalytic activity. The PMO-ICS-Pr-SO3H catalyst was characterizred by Fourier transform infrared (FTIR) spectroscopy, thermogravimetry analysis (TGA) and N2 adsorption-desorption isotherms techniques as well as field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray (EDX) spectroscopy. Compared to the classical methodologies, this method illustrated significant advantages including low loading of the catalyst, high to excellent yields, short reaction times, avoiding the use of toxic transition metals or reactive reagents for modification of the catalytic activity, easy separation and purification of the products, and reusability of the catalyst.