Humic Acid: A Green‐Catalyst‐Mediated Solvent‐Free Synthesis of Functionalized Diethyl(Phenyl(phenylamino)methyl)phosphonate

Abstract

Humic acid, a high molecular weight, environment friendly biopolymer has been investigated as a catalyst for a straightforward and versatile one‐pot three‐component reaction through famous Kabachnik‐Fields reaction for the diversity‐oriented convergent synthesis of diethyl(phenyl(phenylamino)methyl)phosphonate by using aldehydes, amines and diethyl phosphite under solvent‐free reaction condition. The developed reaction protocol has successfully removed the use of hazardous solvent, toxic reagent, metal catalyst and harsh reaction condition for the synthesis of this important class of compound. The eco‐benign reaction condition, low catalyst loading, easy reaction set‐up, good yield and broad range of functional group tolerance are the key advantages of the reported protocol. Furthermore, the solvent free reaction protocol using humic acid, as a green, non‐toxic, easily available, biodegradable and easily recycled polymeric catalyst convincingly enhances the superiority of this newly developed protocol over the conventional one.