In Situ Generation of N-Triflylimino-λ3-iodanes: Application to Imidation of Phosphines and Catalytic α-Amidation of 1,3-Dicarbonyl Compounds
Shun Sunagawa, Fumiya Morisaki, Takafumi Baba, Akira Tsubouchi, Akira Yoshimura, Kazunori Miyamoto, Masanobu Uchiyama and Akio Saito*
*Division of Applied Chemistry, Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan,
Email: akio-sai
cc.tuat.ac.jp
S. Sunagawa, F. Morisaki, T. Baba, A. Tsubouchi, A. Yoshimura, K. Miyamoto, M. Uchiyama, A. Saito, Org. Lett., 2022, 24, 5230-5234.
DOI: 10.1021/acs.orglett.2c02264
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Abstract
N-Triflylimino-λ3-iodanes, which can be generated in situ from iodosylarene and triflylamide, can be used for imidations of phosphines and α-amidations of 1,3-dicarbonyl compounds without any other additives. The imino-λ3-iodanes can also be catalytically generated from an iodoarene precatalyst with oxone and triflylamide.
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α-Amidation Procedure
To a suspension of iodosylbenzene (0.6 mmol, 1.5 equiv) in CH2Cl2 (4.0 mL) was added trifluoromethanesulfonamide (0.6 mmol, 1.5 equiv). After being stirred for 5 min at room temperature, 1,3-dicarbonyl compound (0.4 mmol) was added and then the reaction mixture was stirred for 2 h at the same temperature. The reaction mixture was concentrated in vacuo to dryness and then insoluble trifluoromethanesulfonamide was removed using a mixed solvent of hexane and CH2Cl2 (4:1). After concentrating the above solution, the residue was purified by silica gel column chromatography and/or MPLC (hexane:AcOEt = 5:1 to 3:2 or hexane:CH2Cl2 = 1:4) to give the desired products. In cases of α-amidated diketones, recrystallization was performed using hexane and CH2Cl2 for further purification.
Key Words
ID: J54-Y2022
