Unity is Strength

Heterocyclic compounds play an important role in Chemistry and thanks to their unique pharmacological and biological activities, they have attracted the interests of chemists for centuries. The direct C—H activation constitutes a new economical choice to the classical metal-catalyzed cross-coupling reactions, because it reduces the loss in yield and efficiency, by adopting a smaller number of purification steps and a straightforward synthetical methodology. This chapter aims s to shed light on to the recent results about the combination of cascade reactions and C—H activations to synthetize nitrogen-based heterocyclic compounds. The reactions include rhodium promoted reactions, palladium promoted reactions, ruthenium promoted reactions, cobalt promoted reactions, and miscellaneous reactions. The chapter focuses on the synthetical ways and mechanism of the saturated and non-aromatic ones.