Zirconium(IV)-modified silica gel: Preparation, characterization and catalytic activity in the synthesis of some biologically important molecules

Zirconium modified silica gel was prepared by the grafting method and the resulting organic–inorganic hybrid material was found to be a highly effective catalyst for the range of organic transformations such as syntheses of coumarins, quinoxalines and 2,4,5-trisubstituted imidazoles. The low percentage of zirconium in the catalyst gave products in high turnover numbers; the catalyst was recovered after reaction, and reused. The structure of the catalyst was investigated and confirmed by surface area (BET), FT-IR, ED-XRF and elemental analyses, 13C-CPMAS spectral studies, molecular mechanics studies and inductively coupled plasma mass spectrometry technique (ICP-MS).

Graphical AbstractSilica-supported zirconium complex has been found to be an efficient and recyclable catalyst for the synthesis of a number of biologically important molecules in high turnover numbers and rates. Figure optionsDownload full-size imageDownload as PowerPoint slideResearch Highlights►Synthesis of zirconium modified silica gel using the grafting method. ►Characterization and application of organic–inorganic hybrid material in catalysis. ►Recyclable and efficient catalyst. ►Synthesis of coumarins, quinoxalines and imidazole derivates in high TONs.