TITLE:
The Nature of the True Catalyst in Transfer Hydrogenation with Alcohol Donors Using (arene)2Ru2Cl4(II)/TsDPEN Precursor
AUTHORS:
Judith Toubiana, Liraz Medina, Yoel Sasson
KEYWORDS:
Catalytic transfer Hydrogenation (CTH), Asymmetric Transfer Hydrogenation (ATH), Ruthenium Nanoparticles, Ruthenium Complexes, Nanocatalyst, Chiral Nanoparticles
JOURNAL NAME:
Modern Research in Catalysis,
Vol.3 No.3,
July
15,
2014
ABSTRACT: The widespread precatalyst (prepared in-situ or ex-situ) (arene) RuTsDPEN
advocated for highly effectual asymmetric transfer hydrogenation (ATH)
reactions with 2-propanol as hydrogen donor at ambient conditions, is proven to
be unstable under the strong reducing conditions prevailing in the reaction
mixtures (blend of alcohol and a base such as KOH). We assert that the true catalysts are the ruthenium metal nanoclusters formed swiftly under the reducing
conditions of these systems. The TsDPEN ligand plays a critical role in the
generation and formatting of the active catalyst including wreaking chiral
properties to the so formed catalytic nanoparticles. Kinetic measurements, NMR,
UV-visible spectroscopy, circular dichroism (CD) and TEM analyses corroborate
this argument.