A wide variety of biological activities are possessed by nitrogen, oxygen, and sulfur containing heterocycles and many methods are explored for the preparation of these heterocyclic compounds. Metal catalysts worked with high activity in organic reactions. The synthesis of heterocycles with the help of metal catalysts became very important in organic synthesis. New protocols have been investigated for the synthesis of heterocycles in the last decades. This article mainly focused on the synthesis of six-membered N-heterocylces in the presence of ruthenium catalyst. [GRAPHICS] .