These scientific project deals with synthesis and functionalization of nitrogen heterocycles catalyzed by transition metals. The first part of this project was devoted to the development of a simple and efficient reaction for the N-cyclopropylation of various nitrogen compounds. From cyclopropylboronic acid under copper oxidative coupling conditions, a wide variety of nitrogen compounds have been N-cyclopropylated. This method allows a new access to N-cyclopropylated substrates.The second part of this work deals with benzimidazoles synthesis. These nitrogen heterocycles have been obtained from amidines through a sequence involving a N-arylation reaction followed by cyclization via a C-H bond functionalization.The third part of this manuscript focuses on pyrroles synthesis. Pyrroles are known for their abundance in biologically active molecules. We have developed a new sequential one-pot procedure for poly-functionalized N-H pyrroles synthesis. Through a enaminone formation catalyzed by indium (III), followed by a palladium catalyzed heteroannulation, various N-H pyrroles have been synthesizedThe final part of this scientific project describes our approach to total synthesis of an alkaloid: the (-)-norsuavéoline. The specificity of our approach was based on the formation of pyridine ring in the beginning of the synthesis and a late formation of indole ring. To date, we have developed and optimized the pyridine synthesis from L-(-)-glutamic acid. Studies are ongoing in the laboratory to obtain the indole part and complete the synthesis of this natural product.