34386-42-0Relevant articles and documents
The solvent determines the product in the hydrogenation of aromatic ketones using unligated RhCl3as catalyst precursor
Bartling, Stephan,Chakrabortty, Soumyadeep,De Vries, Johannes G.,Kamer, Paul C. J.,Lund, Henrik,Müller, Bernd H.,Rockstroh, Nils
, p. 7608 - 7616 (2021/12/13)
Alkyl cyclohexanes were synthesized in high selectivity via a combined hydrogenation/hydrodeoxygenation of aromatic ketones using ligand-free RhCl3 as pre-catalyst in trifluoroethanol as solvent. The true catalyst consists of rhodium nanoparticles (Rh NPs), generated in situ during the reaction. A range of conjugated as well as non-conjugated aromatic ketones were directly hydrodeoxygenated to the corresponding saturated cyclohexane derivatives at relatively mild conditions. The solvent was found to be the determining factor to switch the selectivity of the ketone hydrogenation. Cyclohexyl alkyl-alcohols were the products using water as a solvent.
Visible-Light-Driven Catalytic Deracemization of Secondary Alcohols
Hu, Xile,Zhang, Zhikun
supporting information, p. 22833 - 22838 (2021/09/09)
Deracemization of racemic chiral compounds is an attractive approach in asymmetric synthesis, but its development has been hindered by energetic and kinetic challenges. Here we describe a catalytic deracemization method for secondary benzylic alcohols which are important synthetic intermediates and end products for many industries. Driven by visible light only, this method is based on sequential photochemical dehydrogenation followed by enantioselective thermal hydrogenation. The combination of a heterogeneous dehydrogenation photocatalyst and a chiral molecular hydrogenation catalyst is essential to ensure two distinct pathways for the forward and reverse reactions. These reactions convert a large number of racemic aryl alkyl alcohols into their enantiomerically enriched forms in good yields and enantioselectivities.
Chiral Imidazo[1,5- a]pyridine-Oxazolines: A Versatile Family of NHC Ligands for the Highly Enantioselective Hydrosilylation of Ketones
Chinna Ayya Swamy,Varenikov, Andrii,Ruiter, Graham De
supporting information, p. 247 - 257 (2020/02/04)
Herein we report the synthesis and application of a versatile class of N-heterocyclic carbene ligands based on an imidazo[1,5-a]pyridine-3-ylidine backbone that is fused to a chiral oxazoline auxiliary. The key step in the synthesis of these ligands involves the installation of the oxazoline functionality via a microwave-assisted condensation of a cyano-azolium salt with a wide variety of 2-amino alcohols. The resulting chiral bidentate NHC-oxazoline ligands form stable complexes with rhodium(I) that are efficient catalysts for the enantioselective hydrosilylation of structurally diverse ketones. The corresponding secondary alcohols are isolated in good yields (typically >90%) with good to excellent enantioselectivities (80-93% ee). The reported hydrosilylation occurs at ambient temperatures (40 °C), with excellent functional group tolerability. Even ketones bearing heterocyclic substituents (e.g., pyridine or thiophene) or complex organic architectures are hydrosilylated efficiently, which is discussed further in this report.
