Catalytic Enantioselective Alkyne Addition to Nitrones Enabled by Tunable Axially Chiral Imidazole-Based P,N-Ligands
Shengkang Yin, Kendall N. Weeks, Aaron Aponick*
*Florida Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States,
Email: aponickchem.ufl.edu
S. Yin, K. N. Weeks, A. Aponick, J. Am. Chem. Soc., 2024, 146, 7185-7190.
DOI: 10.1021/jacs.4c00873
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Abstract
An efficient Cu-catalyzed enantioselective alkyne addition to a wide range of nitrones utilizing tunable axially chiral imidazole-based P,N-ligands provides chiral propargyl N-hydroxylamines in good yields and enantioselectivity. A diverse array of optically active nitrogen-containing compounds can be accessed through facile transformations of the reaction products.
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Applications of Chiral Propargyl NHydroxylamines
Details
The document discusses a study on the catalytic enantioselective alkyne addition to nitrones using tunable axially chiral imidazole-based P,N-ligands. This method, developed by Shengkang Yin, Kendall N. Weeks, and Aaron Aponick, represents the first Cu-catalyzed enantioselective alkyne addition to nitrones, overcoming challenges in reactivity and selectivity. The approach utilizes a Cu-StackPhos catalyst and various activating reagents, achieving high yields and enantioselectivity. The study highlights the importance of ligand design, with the 2-furyl-substituted phosphine ligand L6 providing optimal results. The method accommodates a wide range of nitrones and alkynes, enabling the synthesis of chiral propargyl N-hydroxylamines. These compounds are valuable for further transformations into diverse chiral nitrogen-containing compounds, such as 4-isoxazolines and 2-acylaziridines. The research addresses limitations of previous Zn- or In-catalyzed processes and offers a streamlined synthesis route for chiral propargyl N-hydroxylamines, with potential applications in pharmaceuticals and agrochemicals. The study was supported by the University of Florida and the National Institutes of Health. Further details and experimental data are available in the supporting information.
Key Words
ID: J48-Y2024