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.

Rapid four-component synthesis of dihydropyrano[2,3-c]pyrazoles using nano-eggshell/Ti(IV) as a highly compatible natural based catalyst

Nano-eggshell/Ti(IV) as a novel naturally based catalyst was prepared, characterized and applied for the synthesis of dihydropyrano[2,3-c]pyrazole derivatives. The characterization of nano-eggshell/Ti(IV) was performed using Fourier Transform Infrared spectroscopy, X-ray Diffraction, Field Emission Scanning Electron Microscopy, Energy-Dispersive X-ray Spectroscopy, and Thermo Gravimetric Analysis. Dihydropyrano[2,3-c]pyrazoles were synthesized in the presence of nano-eggshell/Ti(IV) via a four component reaction of aldehydes, ethyl acetoacetate, malononitrile and hydrazine hydrate at room temperature under solvent free conditions. The principal affairs of this procedure are mild condition, short reaction times, easy work-up, high yields, reusability of the catalyst and the absence of toxic organic solvents.

Application of highly efficient and reusable H3PW12O40/Fe3O4@SiO2-Pr-Pi nanocatalyst for preparation of dihydro-2-oxypyrrole derivatives

In this study, a novel heterogeneous catalyst (H3PW12O40/Fe3O4@SiO2-Pr-Pi) was prepared via immobilization of H3PW12O40 on the surface of piperidine modified magnetic nanoparticles (Fe3O4@SiO2-Pr-Pi). The synthesis of dihydro-2-oxypyrrole derivatives was carried out by the reaction of substituted aniline, formaldehyde, and dimethyl acetylenedicarboxylate, promoted by H3PW12O40/Fe3O4@SiO2-Pr-Pi in EtOH. The formation of resultant catalyst was confirmed by FTIR spectroscopy, FE-SEM, EDX, VSM, and TGA techniques. The magnetically separable and environmentally friendly nanostructured catalyst remained quite stable during reaction conditions and was reused for at least five recycle runs.

Synthesis of functionalized dihydro-2-oxopyrroles using graphene oxide as heterogeneous catalyst

A mild, efficient synthetic approach for the synthesis of highly functionalized dihydro-2-oxopyrroles is developed by using graphene oxide, a readily available and inexpensive material, as an eco-benign solid acid catalyst in ethanol at room temperature. The present methodology displays several advantages such as practical simplicity, high atom economy, easy workup procedure, and high yields of the products.

Covalently anchored sulfamic acid on cellulose as heterogeneous solid acid catalyst for the synthesis of structurally symmetrical and unsymmetrical 1,4-dihydropyridine derivatives

A novel heterogeneous solid acid catalyst has been prepared by covalent grafting of chlorosulphonic acid on amino-functionalized cellulose (Cell–Pr-NHSO₃H).

Synthesis of highly substituted dihydro-2-oxopyrroles using Fe3O4@nano-cellulose–OPO3H as a novel bio-based magnetic nanocatalyst

A green and environmentally friendly approach for the synthesis of dihydro-2-oxopyrrole derivatives was developed using Fe₃O₄@nano-cellulose–OPO₃H as a novel bio-based magnetic nanocatalyst.

An expedient synthesis of oxazolones using a cellulose supported ionic liquid phase catalyst

A novel cellulose supported ionic liquid phase catalyst has been synthesized and effectively employed as a heterogeneous catalyst in the synthesis of oxazolones.

The UiO-66-SO3H metal–organic framework as a green catalyst for the facile synthesis of dihydro-2-oxypyrrole derivatives

The multicomponent domino reaction synthesis of dihydro-2-oxopyrroles has been performed using the sulfonated metal–organic framework, UiO-66-SO₃H (UiO is the University of Oslo), as a highly efficient acid catalyst.