South African Journal of Chemistry
versión On-line ISSN 1996-840X
MIRJALILI, Bi Bi Fatemeh y ZAMANI, Leila. Nano-TiCl4.SiO2: a versatile and efficient catalyst for synthesis of dihydropyrimidones via Biginelli condensation. S.Afr.j.chem. (Online) [online]. 2014, vol.67, pp. 21-26. ISSN 1996-840X.
Nano-TiCl4.SiO2 has been found to be an extremely efficient catalyst for the preparation of 3,4-dihydropyrimidinones/thiones via three-component reactions of an aldehyde, β-ketoester or β-diketone and urea or thiourea under mild conditions. Nano-TiCl4.SiO2 as a solid Lewis acid has been synthesized by reaction of nano-SiO2 and TiCl4. The structural characterization of this acid has been studied by FT-IR (ATR), XRD, SEM and TEM. This process was simple and environmentally benign with high to excellent yields. Furthermore, the catalyst could be recovered conveniently and reused for at least three times.
Palabras clave : Nano-TiCl4.SiO2; heterogeneous catalyst; multi-component reaction; β-ketoester; β-diketone; urea.