1. Selective Base-free Transfer Hydrogenation of α,β-Unsaturated Carbonyl Compounds using iPrOH or EtOH as Hydrogen Source.
- Author
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Farrar-Tobar, Ronald A., Zhihong Wei, Haijun Jiao, Hinze, Sandra, and de Vries, Johannes G.
- Subjects
TRANSFER hydrogenation ,CARBONYL compounds ,HYDROGEN ,FUNCTIONAL groups ,ALCOHOLS (Chemical class) - Abstract
Commercially available Ru-MACHO
TM -BH is an active catalyst for the hydrogenation of several functional groups and for the dehydrogenation of alcohols. Herein, we report on the new application of this catalyst to the base-free transfer hydrogenation of carbonyl compounds. Ru-MACHOTM -BH proved to be highly active and selective in this transformation, even with α,β-unsaturated carbonyl compounds as substrates. The corresponding aliphatic, aromatic and allylic alcohols were obtained in excellent yields with catalyst loadings as low as 0.1–0.5 mol % at mild temperatures after very short reaction times. This protocol tolerates iPrOH and EtOH as hydrogen sources. Additionally, scale up to multi-gram amounts was performed without any loss of activity or selectivity. An outer-sphere mechanism has been proposed and the computed kinetics and thermodynamics of crotonaldehyde and 1-phenyl-but-2-en-one are in perfect agreement with the experiment. [ABSTRACT FROM AUTHOR]- Published
- 2018
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