Palladium-catalyzed C–N bond formation via direct C–H bond functionalization. Recent developments in heterocyclic synthesis

The formation of carbon–nitrogen bonds by reaction between a nitrogen atom and an unactivated carbon–hydrogen bond is a highly atom-economical process that attracted the attention of the chemists in the last two decades. The widely useful amination and hydroamination reactions, which furnish acyclic or cyclic products, give access to various nitrogen-containing basic and fine chemicals. This review highlights recent progress in the development of palladium-catalyzed reactions that occur by direct functionalization of simple carbon–hydrogen bonds to give heterocyclic products. Pd(0)- and Pd(II)-catalyzed reactions are described separately, emphasizing the different behavior of the metal in these two oxidation states.

Graphical abstractThis review highlights recent progress in the development of palladium-catalyzed reactions that occur by activation of simple carbon–hydrogen bonds to give heterocyclic products. Pd(0)- and Pd(II)-catalyzed reactions are described separately, emphasizing the different behavior of the metal in these two oxidation states.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► Pd-catalyzed amination and hydroamination reactions. ► Synthesis of nitrogen-containing heterocycles through Pd-catalysis. ► Pd-catalyzed C–N bond formation in heterocyclic synthesis. ► Pd-catalyzed direct amination of C–H bonds.