Journal ArticleDOI
trans-RuH(η1-BH4)(binap)(1,2-diamine): A Catalyst for Asymmetric Hydrogenation of Simple Ketones under Base-Free Conditions
Reads0
Chats0
TLDR
The TolBINAP/DPEN Ru complex allows for asymmetric hydrogenation of simple ketones in 2-propanol without an additional strong base and overcomes the drawback of an earlier method using RuCl2(diphosphine)(diamine) and an alkaline base.Abstract:
Reaction of a chiral RuCl2(diphosphine)(1,2-diamine) complex and NaBH4 forms trans-RuH(η1-BH4)(diphosphine)(1,2-diamine) quantitatively. The TolBINAP/DPEN Ru complex has been characterized by single crystal X-ray analysis as well as NMR and IR spectra. The new Ru complexes allow for asymmetric hydrogenation of simple ketones in 2-propanol without an additional strong base. Various base-sensitive ketones are convertible to chiral alcohols in a high enantiomeric purity with a substrate/catalyst ratio of up to 100 000 under mild conditions. Configurationally unstable 2-isopropyl- and 2-methoxycyclohexanone can be kinetically resolved with a high enantiomer discrimination. This procedure overcomes the drawback of an earlier method using RuCl2(diphosphine)(diamine) and an alkaline base, which sometimes causes undesired reactions such as ester exchange, epoxy-ring opening, β-elimination, and polymerization of ketonic substrates.read more
Citations
More filters
Journal ArticleDOI
Catalysis in ionic liquids
TL;DR: Hydrogenation of Alkenes and Arenes by Nanoparticles 2624 3.1.2.
Journal ArticleDOI
New Chiral Phosphorus Ligands for Enantioselective Hydrogenation
Wenjun Tang,Xumu Zhang +1 more
TL;DR: The increasing demand to produce enantiomerically pure pharmaceuticals, agrochemicals, flavors, and other fine chemicals has advanced the field of asymmetric catalytic technologies, and asymmetric hydrogenation utilizing molecular hydrogen to reduce prochiral olefins, ketones, and imines has become one of the most efficient methods for constructing chiral compounds.
Journal ArticleDOI
Mechanisms of the H2-hydrogenation and transfer hydrogenation of polar bonds catalyzed by ruthenium hydride complexes
TL;DR: In this article, the authors classified the catalytic cycles for the H2-hydrogenation (H) and transfer hydrogenation (T) of CO and cN bonds catalyzed by over 100 ruthenium hydride complexes in organic and aqueous media.
Journal ArticleDOI
Bifunctional transition metal-based molecular catalysts for asymmetric syntheses.
TL;DR: The chiral bifunctional Ru catalyst was originally developed for asymmetric transfer hydrogenation of ketones and imines and is now successfully applicable to enantioselective C-C bond formation reaction with a wide scope and high practicability.
Journal ArticleDOI
Mechanism of Asymmetric hydrogenation of ketones catalyzed by BINAP/1,2-diamine-ruthenium(II) complexes
TL;DR: Findings indicate that dual mechanisms are in operation, both of which are dependent on reaction conditions and involve heterolytic cleavage of H(2) to form a common reactive intermediate.
Related Papers (5)
Asymmetric Catalysis by Architectural and Functional Molecular Engineering: Practical Chemo‐ and Stereoselective Hydrogenation of Ketones
Ryoji Noyori,Takeshi Ohkuma +1 more