Metalloporphyrin Catalyzed C–H Amination

Direct C–H bond functionalization to form C–N bonds via nitrenoid insertion is one of the most effective strategies to construct N-functionalized molecules of importance. In this context, metalloporphyrins have established themselves as effective catalytic systems for such transformation, following an outer-sphere pathway. In the past few years C(sp 3 )–H bond amination has progressed in leaps and bounds, tackling the chemo-/regioselectivity issue not only in small molecules but also in complex molecules through late-stage functionalization, furnishing valuable N-scaffolds. It is only very recently that the biocatalytic approach with metalloporphyrin-based enzymes has emerged as a promising research area demonstrating very good regio- and stereoselectivity toward the development of environmentally benign C–H amination processes. Importantly, the progress in aromatic C–H bond amination has also gained prominence lately under metalloporphyrin catalysis. This review covers development achieved to date in metalloporphyrin-catalyzed C–H amination, including the very nascent biocatalytic C–H bond nitrenoid insertion, in addition to providing an insight on the mechanistic aspects as well.