NaI/PPh3-Mediated Photochemical Reduction and Amination of Nitroarenes
Zhonghua Qu, Xing Chen, Shuai Zhong, Guo-Jun Deng and Huawen Huang*
*College of Chemistry, Xiangtan University, Xiangtan 411105, China,
Email: hwhuang
xtu.edu.cn
Z. Qu, X. Chen, S. Zhong, G.-J. Deng, H. Huang, Org. Lett., 2021, 23, 5349-5353.
DOI: 10.1021/acs.orglett.1c01654
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Abstract
A mild transition-metal- and photosensitizer-free photoredox system based on the combination of NaI and PPh3 enables a highly selective reduction of nitroarenes. This protocol tolerates a broad range of reducible functional groups such as halogen (even I), aldehyde, ketone, carboxyl, and cyano.
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General Procedure:
A 20 mL reaction vessel was charged with NaI (12 mg, 0.08 mmol), nitroarene (0.2 mmol), PPh3 (10.5 mg, 0.04 mmol) and PhSiH3 (50 µL, 0.4 mmol) in 2.0 mL CHCl3 under Ar atmosphere. The resulting mixture was stirred for 72 h under irradiation with a 35 W blue LEDs at 60°C. The reaction was monitored by TLC. The crude reaction mixture was quenched with saturated sodium carbonate and extracted with dichloromethane (3×10 mL). The extracts were combined, dried over sodium sulfate, and filtered, and the volatiles were removed under reduced pressure. Column chromatography was performed using silica gel (200-300 mesh) or thin layer chromatography was performed using silica gel (GF254) to give reduction product.
Key Words
reduction of nitro compounds, triphenylphosphine, phenylsilane, photochemistry
ID: J54-Y2021
