Rice-husk-supported FeCl3 nano-particles: Introduction of a mild, efficient and reusable catalyst for some of the multi-component reactions

Waste-to-wealth transition: application of natural waste materials as sustainable catalysts in multicomponent reactions

Application of natural waste materials as sustainable catalysts in multicomponent reactions.

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.

A clean synthesis of bis(indolyl)methane and biscoumarin derivatives using P4VPy–CuO nanoparticles as a new, efficient and heterogeneous polymeric catalyst

A mild, simple, and efficient procedure has been developed for the synthesis of bis(indolyl)methanes and 3,3′-(arylmethylene)-bis-(4-hydroxy coumarins) using P₄VPy–CuO nanoparticles as a heterogeneous polymeric catalyst.