This PhD thesis describes the development of new methodologies for the catalytic reduction of carboxylic acid derivatives (nitriles and amides). Initially, an inexpensive organocatalytic hydrosilylation of benzylic nitriles was established. Next more atom-economic, transfer hydrogenation and direct hydrogenation protocols for nitrile reductions were developed. More specifically versatile Ru-catalyzed transfer hydrogenations and related reductive N-monoalkylations of aromatic and aliphatic nitriles were developed. Based on this work, it was found, that Ru- and Fe-complexes catalyze the activation of molecular hydrogen to selectively reduce a broad variety of aliphatic, aromatic and heteroaromatic (di)nitriles.
Finally, the hydrosilylation of the more challenging amides was tested employing Rh-catalysts. Indeed, a chemoselective reduction protocol for tertiary amides in the presence of various functional groups was developed and successfully applied to small and medium-sized peptides, as well as beta-lactam rings.