UV-Light-Induced N-Acylation of Amines with α-Diketones
Zhihui Xu, Tianbao Yang, Niu Tang, Yifeng Ou, Shuang-Feng Yin, Nobuaki Kambe and Renhua Qiu*
*State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China, Email: renhuaqiu1hnu.edu.cn
Z. Xu, T. Yang, N. Tang, Y. Ou, S.-F. Yin, N. Kambe, R. Qiu, Org. Lett., 2021, 23, 5329-5333.
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A mild method for N-acylation of primary and secondary amines with α-diketones in high yield is induced by ultraviolet (UV) light at room temperature. This system can also be applied to the synthesis of several amino acid derivatives. Mechanistic studies show that benzoin is generated in situ from benzil under UV irradiation.
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A mixture of benzil (0.20 mmol), amines (0.40 mmol), and THF (2.0 mL) in a transparent glass bottle (equipped with a magnetic stirring bar) was vigorously stirred at room temperature for 10-24 hours under three UV lamps (26 W, 350-380 nm). Target products were purified by column chromatography (petroleum ether/ethyl acetate = 2/1).
Renhua Qiu, April 24, 2022