The role of the aromatic ligand in the asymmetric transfer hydrogenation of the CN bond on Noyori’s chiral Ru catalysts
摘要:
Only four types of dimeric precursors [RuCl2(eta(6)-arene)](2) for the synthesis of Noyori's half sandwich diamine catalysts [RuCl(TsDPEN)(eta(6)-arene)] are commercially available, yet so far no study has tried to systematically evaluate how these systems perform during the asymmetric transfer hydrogenation of various 3,4-dihydroisoquinolines (i.e., the typical substrates for Noyori asymmetric transfer hydrogenation benchmarking). Experiments combined with molecular modeling allowed us to assess their properties and formulate a hypothesis clarifying the difference in enantioselectivity of these systems. (C) 2014 Elsevier Ltd. All rights reserved.
The role of the aromatic ligand in the asymmetric transfer hydrogenation of the CN bond on Noyori’s chiral Ru catalysts
摘要:
Only four types of dimeric precursors [RuCl2(eta(6)-arene)](2) for the synthesis of Noyori's half sandwich diamine catalysts [RuCl(TsDPEN)(eta(6)-arene)] are commercially available, yet so far no study has tried to systematically evaluate how these systems perform during the asymmetric transfer hydrogenation of various 3,4-dihydroisoquinolines (i.e., the typical substrates for Noyori asymmetric transfer hydrogenation benchmarking). Experiments combined with molecular modeling allowed us to assess their properties and formulate a hypothesis clarifying the difference in enantioselectivity of these systems. (C) 2014 Elsevier Ltd. All rights reserved.
A method for enantioselective hydrogenation of cyclic imines with gaseous hydrogen has been developed. Easily accessible Noyori-Ikariya Ru(II) and Rh(III) complexes can be used directly without inert atmosphere. Substrate activation...
The asymmetric transfer hydrogenation of five dihydroisoquinolines (DHIQs) was studied by NMR spectroscopy. The DHIQs differed by substitution with methoxy groups, which had a significant effect upon the reaction performance in terms of reaction rate and enantioselectivity. The differences are most probably related to the basicity of DHIQs.