Silica Gel-Supported Polyphosphoric Acid (PPA/SiO₂): An Efficient and Reusable Heterogeneous Catalyst for Facile Synthesis of 14-Aryl-14H-dibenzo[a,j]xanthenes under Solvent-free Conditions

摘要

A simple, efficient and green method for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes by a one-pot condensation reaction of β-naphthol and aryl aldehydes using silica gel-supported polyphosphoric acid (PPA/SiO₂), an effective and reusable catalyst, under solvent-free conditions is described. The present methodology offers several advantages, such as a simple procedure with an easy work-up, short reaction times, high yields, and the absence of any volatile and hazardous organic solvents.