Catalytic activity of tungstophosphoric acid supported on carriers of diverse acidity in the synthesis of enaminones
Tungstophosphoric acid (PW), supported on different metal oxide (TiO2, γ-Al2O3, K 10 and KSF) and activated carbon were used in the condensation of aniline with ethylacetoacetate to afford the corresponding β-enaminone. Catalytic activity was discussed in relation with the acid strength of catalysts. The best catalytic activity was obtained with PW/TiO2. Effect of PW loading, solvent and catalyst reusability was studied to introduce the best reaction conditions. Based on the above experimental findings, various β-enaminones were synthesized in excellent yield within a few minutes under solvent free condition.
Graphical abstractThe catalytic activity of various supported Keggin-type heteropoly acid was studied in the synthesis of β-enaminones and β-enaminoesters. The activity of these catalysts is dependent on the acidity and textural properties of the supported catalysts.Figure optionsDownload full-size imageDownload as PowerPoint slide
Journal: Applied Catalysis A: General - Volume 352, Issues 1–2, 15 January 2009, Pages 202–207