A highly efficient iridium-catalyzedhydrogenation of alpha,beta-unsaturated carboxylic acids has been developed by using chiral spiro-phosphino-oxazoline ligands, affording alpha-substituted chiral carboxylic acids in exceptionally high enantioselectivities and reactivities.
Copper‐Catalyzed C−P Cross‐Coupling of (Cyclo)alkenyl/Aryl Bromides and Secondary Phosphine Oxides with
<i>in</i>
<i>situ</i>
Halogen Exchange
作者:Paweł Woźnicki、Marek Stankevič
DOI:10.1002/ejoc.202100456
日期:2021.6.25
A protocol for copper-catalyzed halogen exchange/C−P cross-coupling between (cyclo)alkenyl/arylbromides and secondary phosphine oxides has been developed. The addition of sodium iodide increases the yield of the cross-coupling by promoting in situ halogen exchange of organic bromides to the corresponding iodides.
groups and ethylzinc carboxamidates from these ligands as catalysts for Et2Zn additions to aldehydes were reported. Excellent yields were obtained with moderate ee′s in Et2Zn additions to benzaldehyde derivatives, implying effectiveness of our newly designed catalytic structures as well as mediocre stereocontrol by these chiral ligands. Possible transition states were suggested based on the crystal structures
Asymmetric Synthesis of Chiral Primary Amines by Ruthenium-Catalyzed Direct Reductive Amination of Alkyl Aryl Ketones with Ammonium Salts and Molecular H<sub>2</sub>
amination of simple ketones. The strategy makes use of ammonium acetate as the amine source and H2 as the reductant and is a user-friendly and operatively simple access to industrially relevant primary amines. Excellent enantiocontrol (>90% ee for most cases) was achieved with a wide range of alkylarylketones. The practicability of this methodology has been highlighted by scalable synthesis of key intermediates