Metal-catalyzed nitrile hydration reactions: The specific contribution of ruthenium

The hydration of nitriles is an atom economical route to generate primary amides of great academic and industrial significance. From an academic perspective, considerable progress has been made toward the development of transition metal catalysts able to promote this hydration process under mild conditions. In this context, with regard to activity, selectivity, functional group compatibility and modes of reactivity, the most versatile nitrile hydration catalysts discovered to date are based on ruthenium complexes. Herein, a comprehensive account of the different homogeneous ruthenium catalysts described in the literature is presented. Heterogeneous ruthenium-based systems are also discussed. (C) 2014 Elsevier B.V. All rights reserved.