17 - Metal oxide composites in organic transformations

Abstract

Metal oxide-based catalysts have been used as promising heterogeneous catalysts for various organic transformations. To further improve the catalytic activity and stability of the catalysts, various composites of metal oxides with different material are reported. Such composites include binary as well as ternary composites, some notable examples are Au–ZrO2, Bi2O3–ZnO, CeO2–MWCNT, CoFe2O4@B2O3–SiO2, Bi2O3–ZnO, MgO–ZrO2, and so on. Several organic transformations have been studied with metal oxide-based composites, which include multicomponent reactions, click reactions, condensation reactions, coupling reactions, and so on. The use of these composites can offer several advantages such as easy to use and reuse, easy work-up procedure, and reduced waste. These catalysts are a good alternative to other homogeneous catalysts to reduce water pollution caused by the use of hazardous chemicals during the reactions and work-up. In this chapter, selected organic synthesis reactions carried out by using metal oxide-based composites have been discussed.