Directing group-assisted selective C-H activation of six-membered N-heterocycles and benzo-fused N-heterocycles

Heterocycles are found to be present as the fundamental core compositions of many natural products, agrochemicals, and pharmaceuticals. Among all, the nitrogen-containing heterocycles hold a unique position as a valuable source of therapeutic drugs in medicinal chemistry. Remarkably, the majority of FDA-approved drugs are nitrogen-containing heterocyclic compounds. In this regard, significant progress has been made in this area for the C-H functionalisation of N-heterocycles in the last few decades. Recently, transition metal-catalysed C-H bond activation/functionalisation utilising N-heterocycles as directing group has emerged as a powerful technique. However, the C-H bond activation/functionalisation of N-heterocycles is itself challenging due to the favourable possibility of the metal coordinating to the heteroatom, thus preventing it from activating the desired C-H bond. Therefore, it is essential to emphasise the substantial progress made in this area from a synthetic as well as a medicinal chemistry point of view. Herein, we present the recent advancements made in the directing group-assisted selective C-H bond activation/functionalisation of six-membered N-heterocycles and benzo-fused N-heterocycles, along with some of our thoughts on the future aspects in this area. Directing group-assisted selective C-H bond activation of six-membered N-heterocycles and benzo-fused N-heterocycles has been reported.