56-57-5Relevant articles and documents
Nitration of quinoline 1-oxide: Mechanism of regioselectivity
Yokoyama, Akihiro,Ohwada, Tomohiko,Saito, Shinichi,Shudo, Koichi
, p. 279 - 283 (1997)
The acidity dependence of orientation in the nitration of quinoline 1- oxide was investigated by using the trifluoromethanesulfonic acid (TFSA)- trifluoroacetic acid (TFA) system and the antimony pentafluoride (SbF5)- TFSA system. These systems provide a wider range of acidity than that of aqueous sulfuric acid. Comparison of the behavior of quinoline 1-oxide and 1- methoxyquinolinium triflate in acidic and neutral media demonstrated that O- protonated quinoline 1-oxide is nitrated at the 5- and 8-positions, and the free (unprotonated) molecule is nitrated at the 4-position. This result is consistent with theoretical expectation. It was also discovered that nitration at the 5-position increasingly predominates over that at the 8- position as the acidity is increased.
Hypervalent Iodine(III)-Mediated Regioselective Cyanation of Quinoline N-Oxides with Trimethylsilyl Cyanide
Xu, Feng,Li, Yuqin,Huang, Xin,Fang, Xinjie,Li, Zhuofei,Jiang, Hongshuo,Qiao, Jingyi,Chu, Wenyi,Sun, Zhizhong
supporting information, p. 520 - 525 (2018/12/13)
A regioselective cyanation of quinoline N-oxides with trimethylsilyl cyanide was developed by using (Diacetoxyiodo) benzene (PIDA) as mediated hypervalent iodine(III) reagent under metal-free and base-free reaction conditions to obtain 2-cyanoquinolines. The efficient PIDA reagent could play the role of an activator of the substrates and an accelerator of N?O bond cleavage. The reaction system featured a wide range of substrate suitability and high yields. The procedure was enlarged gram-scale to synthesize the tuberculosis (TB) inhibitor. Finally, according to some experimental results, a plausible mechanism for the cyanation reaction is proposed. (Figure presented.).
Copper-catalyzed direct amination of quinoline N-oxides via C-H bond activation under mild conditions
Zhu, Chongwei,Yi, Meiling,Wei, Donghui,Chen, Xuan,Wu, Yangjie,Cui, Xiuling
supporting information, p. 1840 - 1843 (2014/05/06)
A highly efficient and concise one-pot strategy for the direct amination of quinoline N-oxides via copper-catalyzed dehydrogenative C-N coupling has been developed. The desired products were obtained in good to excellent yields for 22 examples starting from the parent aliphatic amines. This methodology provides a practical pathway to 2-aminoquinolines and features a simple system, high efficiency, environmental friendliness, low reaction temperature, and ligand, additives, base, and external oxidant free conditions.