Sustainable Amine Synthesis: Iron Catalyzed Reactions of Hydrosilanes with Imines, Amides, Nitroarenes and Nitriles

Iron catalyzed organic synthesis has emerged as a sustainable chemistry due to the highly competitive cost, high natural abundance and ecologically acceptable properties of iron. Moreover, its extensive range of oxidation states i. e. -II to +VI provides numerous opportunities to perform multiple organic reactions. Recently iron catalysis has started competing the established precious metals. Among organic scaffolds, amines are important building blocks that are useful in the various fields starting from drugs, crop protection chemicals to dyes and pigments. Typically, hydrogenation or reduction of functional groups such as imines, amides, nitroarenes and nitriles results into amines. In this context, homogeneous iron catalyzed hydrosilylation is a highly promising alternative to traditional hydrogenation and other reduction reactions. This review is focused on the synthesis of amine and its derivatives via hydrosilylation of imines, amides, nitroarenes and nitriles using iron as a catalyst. Some of the reduction methods of these functional groups that may not follow the typical hydrosilylation pathway are also included in this review due to their strong relevance to the theme. The phenomenal progress in this focused area is summarized to witness this transformation towards sustainable development in the field of amine synthesis.