Methods for Metal and Non-Metal Catalyzed Synthesis of Six-Membered Oxygen Containing Poly-Heterocycles

In recent decades, a large number of reports related to synthesis of N, O and S containing heterocycles have appeared owing to a wide variety of their biological activity. We need a catalyst system that not only shows high activity and selectivity but also possesses the ease of catalyst separation and recovery. Therefore, the different metals are used as a catalyst for the synthesis of oxygen containing heterocyclic compounds. This review focuses on the use of metal as a catalyst for the synthesis of O-heterocylces. It describes the formation of sixmembered heterocyclic rings.