La2O3/TFE: An efficient system for room temperature synthesis of Hantzsch polyhydroquinolines

Lanthanum oxide (La2O3) in combination with 2,2,2-trifluoroethanol (TFE) was found to be an efficient system for the one-pot, four-component synthesis of Hantzsch polyhydroquinoline derivatives from aromatic aldehydes, dimedone, ethyl acetoacetate and ammonium acetate at ambient temperature. The catalyst is heterogeneous and reusable, hence can be separated easily and reused. The present method is featured by mild reaction conditions, use of heterogeneous catalyst, non-chromatographic purification, short reaction time and high yields, which make it an attractive route for the synthesis of polyhydroquinolines.

Graphical abstractLanthanum oxide (La2O3) in combination with 2,2,2-trifluoroethanol (TFE) was found to be an efficient system for the one-pot, four-component synthesis of Hantzsch polyhydroquinoline derivatives from aromatic aldehydes, dimedone, ethyl acetoacetate and ammonium acetate at ambient temperature. The catalyst is heterogeneous and reusable, hence can be separated easily and reused. The present method is featured by mild reaction conditions, use of heterogeneous catalyst, non-chromatographic purification, short reaction time and high yields, which make it an attractive route for the synthesis of polyhydroquinolines.Figure optionsDownload full-size imageDownload as PowerPoint slide