Iron-Catalyzed Oxidative α-Amination of Ketones with Primary and Secondary Sulfonamides
Fubin Song, So Hyun Park, Christine Wu and Alexandra E. Strom*
*Department of Chemistry, Smith College, Northampton, Massachusetts 01063, United States,
Email: astrom
smith.edu
F. Song, S. H. Park, C. Wu, A. E. Strom, J. Org. Chem., 2023, 88, 3353-3358.
DOI: 10.1021/acs.joc.3c00210
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Abstract
Iron catalyzes an oxidative coupling approach for α-amination of ketones with free sulfonamides, without the need for prefunctionalization of either substrate. Primary and secondary sulfonamides are both competent coupling partners.
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Amination Reaction - General Procedure:
To an oven-dried 4 mL vial in the glovebox were added ketone (0.200 mmol, 1.00 equiv), DDQ (54.5 mg, 0.240 mmol, 1.20 equiv), sulfonamide (0.6 mmol, 3.0 equiv), iron(III) bromide (11.8 mg, 0.0400 mmol, 0.200 equiv), and an oven-dried stir bar. 1,2-Dichloroethane (1.0 mL, 0.20 M, anhydrous) was added, and the vial was sealed with a PTFE-lined cap, removed from the glovebox, and heated in an aluminum heating block (100 °C, 4 h). The reaction mixture was allowed to cool to room temperature and then opened to air, and 1-2 mL of saturated aqueous NH4Cl was added. The aqueous solution was extracted with DCM until the organic phase was clear, and the combined organic layers were filtered through a pad of silica, washing with 20% MeOH in DCM (10 mL). The solvent was removed in vacuo, and the crude material was purified via flash chromatography (hexanes/ethyl acetate).
Key Words
ID: J42-Y2023
