ja0c00985_si_001.pdf (13.49 MB)
Design of Ru(II)-NHC-Diamine Precatalysts Directed by Ligand Cooperation: Applications and Mechanistic Investigations for Asymmetric Hydrogenation
journal contribution
posted on 2020-03-31, 21:18 authored by Wei Li, Tobias Wagener, Lars Hellmann, Constantin G. Daniliuc, Christian Mück-Lichtenfeld, Johannes Neugebauer, Frank GloriusA modular
synthesis of Ru(II)-NHC-diamine complexes from readily
available chiral N-heterocyclic carbenes (NHCs) and chiral diamines
is disclosed for the first time. The well-defined Ru(II)-NHC-diamine
complexes show unique structure and coordination chemistry including
an unusual tridentate coordination effect of 1,2-diphenylethylenediamine.
The isolated air- and moisture-stable Ru(II)-NHC-diamine complexes
act as versatile precatalysts for the asymmetric hydrogenation of
isocoumarines, benzothiophene 1,1-dioxides, and ketones. Moreover,
on the basis of the identification of reaction intermediates by stoichiometric
reactions and NMR experiments, together with the DFT calculations,
a possible catalytic cycle was proposed.