An Affordable and Eco-friendly Method for Pseudo-five-component Synthesis of Tetrahydropyridines Using Gum Arabic-OPO۳H۲ as a Natural-based Catalyst

This study describes a facile and environmentally friendly protocol for the synthesis of highly functionalized tetrahydropyridines via pseudo-five-component reaction of aromatic aldehydes, various amines and ethyl acetoacetate using GA-OPO۳H۲ as a metal free and natural-based catalyst. In addition to the easy preparation of GA-OPO۳H۲ from bio-renewable materials, this catalyst can also be recycled and reused without obvious loss of catalytic activity. The synthesis of tetrahydropyridines via this new green methodology offers significant advantages in terms of no use of a solvent, no hazardous waste, uncomplicated work-up and high yields of products.

Keywords:

Gum Arabic-OPO۳H۲ , Natural-based catalyst , Tetrahydropyridine , Pseudo-five-component reaction , Solvent-free condition