Search Results
Cobalt pincer complexes for catalytic reduction of nitriles to primary amines
2019, Schneekönig, Jacob, Tannert, Bianca, Hornke, Helen, Beller, Matthias, Junge, Kathrin
Various cobalt pincer type complexes 1-6 were applied for the catalytic hydrogenation of nitriles to amines. Among these, catalyst 4 is the most efficient, allowing the reduction of aromatic as well as aliphatic nitriles in moderate to excellent yields. © 2019 The Royal Society of Chemistry.
Efficient and selective hydrogenation of amides to alcohols and amines using a well-defined manganese-PNN pincer complex
2017, Papa, Veronica, Cabrero-Antonino, Jose R., Alberico, Elisabetta, Spanneberg, Anke, Junge, Kathrin, Junge, Henrik, Beller, Matthias
Novel well-defined NNP and PNP manganese pincer complexes have been synthetized and fully characterized. The catalyst Mn-2 containing an imidazolyaminolphosphino ligand shows high activity and selectivity in the hydrogenation of a wide range of secondary and tertiary amides to the corresponding alcohols and amines, under relatively mild conditions. For the first time, more challenging substrates like primary aromatic amides including an actual herbicide can also be hydrogenated using this earth-abundant metal-based pincer catalyst.
Highly selective hydrogenation of amides catalysed by a molybdenum pincer complex : Scope and mechanism
2019, Leischner, Thomas, Suarez, Lluis Artús, Spannenberg, Anke, Nova, Ainara, Junge, Kathrin, Nova, Ainara, Beller, Matthias
A series of molybdenum pincer complexes has been shown for the first time to be active in the catalytic hydrogenation of amides. Among the tested catalysts, Mo-1a proved to be particularly well suited for the selective C-N hydrogenolysis of N-methylated formanilides. Notably, high chemoselectivity was observed in the presence of certain reducible groups including even other amides. The general catalytic performance as well as selectivity issues could be rationalized taking an anionic Mo(0) as the active species. The interplay between the amide CO reduction and the catalyst poisoning by primary amides accounts for the selective hydrogenation of N-methylated formanilides. The catalyst resting state was found to be a Mo-alkoxo complex formed by reaction with the alcohol product. This species plays two opposed roles-it facilitates the protolytic cleavage of the C-N bond but it encumbers the activation of hydrogen. This journal is © The Royal Society of Chemistry.