Recent developments in the preparation of N-heterocycles using Pd-catalysed C-H activation

The direct and selective activation of C-H bonds for the synthesis of N-heterocycles (C-N bonds) is an important area in modern synthetic chemistry due to its wide application in both in academics and industry. These compounds are frequently found as backbones in bioactive molecules and fine chemicals and are often used as organocatalysts or as auxiliary ligands in transition metal complexes assisted catalyses. Various kinds of palladium-containing complexes as active catalysts in the C(sp(3))-H or C(sp(2))-H bond activation have attracted increasing attention because of their accessibility and catalytic efficiencies. This review summarizes the recent developments in this area which employs Pd-0-Pd-IV as versatile catalyst precursors to the syntheses of N-heterocycles. The N-heterocycles, including five- and six-membered rings, are described separately. Furthermore, some of the asymmetric CeH bond activation and mechanistic aspects of these catalytic reactions are discussed. (C) 2015 Elsevier B.V. All rights reserved.