Homogeneous Catalytic Hydrogenation of Amides to Amines |
| |
| Authors: | Dr Jacorien Coetzee Dr Deborah L Dodds Prof Jürgen Klankermayer Sandra Brosinski Prof Walter Leitner Prof Alexandra M Z Slawin Prof David J Cole‐Hamilton |
| |
| Institution: | 1. EastChem, School of Chemistry, North Haugh, University of St. Andrews, St. Andrews, Fife, KY16 9ST, Scotland (UK);2. Institut für Technische und Makromolekulare Chemie, RWTH Aachen University, Worringerweg 1, 52074 Aachen (Germany);3. Max‐Planck‐Institut für Kohlenforschung, Kaiser‐Wilhelm‐Platz 1, 45470 Mülheim a.d. Ruhr (Germany) |
| |
| Abstract: | Hydrogenation of amides in the presence of Ru(acac)3] (acacH=2,4‐pentanedione), triphos 1,1,1‐tris‐ (diphenylphosphinomethyl)ethane] and methanesulfonic acid (MSA) produces secondary and tertiary amines with selectivities as high as 93 % provided that there is at least one aromatic ring on N. The system is also active for the synthesis of primary amines. In an attempt to probe the role of MSA and the mechanism of the reaction, a range of methanesulfonato complexes has been prepared from Ru(acac)3], triphos and MSA, or from reactions of RuX(OAc)(triphos)] (X=H or OAc) or RuH2(CO)(triphos)] with MSA. Crystallographically characterised complexes include: Ru(OAc‐κ1O)2(H2O)(triphos)], Ru(OAc‐κ2O,O′)(CH3SO3‐κ1O)(triphos)], Ru(CH3SO3‐κ1O)2(H2O)(triphos)] and Ru2(μ‐CH3SO3)3(triphos)2]CH3SO3], whereas other complexes, such as Ru(OAc‐κ1O)(OAc‐κ2O,O′)(triphos)], Ru(CH3SO3‐κ1O)(CH3SO3‐κ2O,O′)(triphos)], HRu(CH3SO3‐κ1O)3(triphos)], RuH(CH3SO3‐κ1O)(CO)(triphos)] and RuH(CH3SO3‐κ2O,O′)(triphos)] have been characterised spectroscopically. The interactions between these various complexes and their relevance to the catalytic reactions are discussed. |
| |
| Keywords: | amide hydrogenation amines catalysis homogeneous catalysis ruthenium |
|
|
