- Transition-Metal-Free Oxidation of Benzylic C-H Bonds of Six-Membered N-Heteroaromatic Compounds
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A novel oxidation of benzylic C-H bonds for the synthesis of diverse six-membered N-heteroaromatic aldehydes and ketones has been developed. The obvious advantages of this approach are the simple operation, mild reaction conditions, and without use of toxic reagent and transition metal. The present method should provide a useful access for the synthesis and modification of N-heterocycles.
- Gao, Xianying,Han, Shuaijun,Zheng, Maolin,Liang, Apeng,Zou, Dapeng,Wu, Yusheng,Wu, Yangjie,Li, Jingya
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p. 4040 - 4049
(2019/04/30)
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- Discovery of Novel Quinoline-Chalcone Derivatives as Potent Antitumor Agents with Microtubule Polymerization Inhibitory Activity
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A series of novel quinoline-chalcone derivatives were designed, synthesized, and evaluated for their antiproliferative activity. Among them, compound 24d exhibited the most potent activity with IC50 values ranging from 0.009 to 0.016 μM in a panel of cancer cell lines. Compound 24d also displayed a good safety profile with an LD50 value of 665.62 mg/kg by intravenous injection, and its hydrochloride salt 24d-HCl significantly inhibited tumor growth in H22 xenograft models without observable toxic effects, which was more potent than that of CA-4. Mechanism studies demonstrated that 24d bound to the colchicine site of tubulin, arrested the cell cycle at the G2/M phase, induced apoptosis, depolarized mitochondria, and induced reactive oxidative stress generation in K562 cells. Moreover, 24d has potent in vitro antimetastasis and in vitro and in vivo antivascular activities. Collectively, our findings suggest that 24d deserves to be further investigated as a potent and safe antitumor agent for cancer therapy.
- Li, Wenlong,Xu, Feijie,Shuai, Wen,Sun, Honghao,Yao, Hong,Ma, Cong,Xu, Shengtao,Yao, Hequan,Zhu, Zheying,Yang, Dong-Hua,Chen, Zhe-Sheng,Xu, Jinyi
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p. 993 - 1013
(2019/01/11)
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- Homolytic Acylation of Protonated Pyridines and Pyrazines with α-Keto Acids: The Problem of Monoacylation
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The silver-catalyzed decarboxylation of α-keto acids by persulfate leads to acyl radicals, which can effect the selective homolytic acylation of pyridine and pyrazine derivatives.Compared with the previously developed source of acyl radicals by hydrogen abstraction from aldehydes, this procedure is more effective in monoacylation when multiple positions of high nucleophilic reactivity are available in the heterocyclic ring.Although the introduction of an acyl group strongly activates the heterocyclic ring toward further substitution, monoacylation can be achieved by taking advantage of the difference in basicity and lipophilicity between the starting base and the monoacylation products in a two-phase system.
- Fontana, Francesca,Minisci, Francesco,Barbosa, Maria Claudia Nogueira,Vismara, Elena
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p. 2866 - 2869
(2007/10/02)
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- Studies on Organometallic Compounds. III. Reaction of Trimethylstannylazines with Acyl Chlorides. A Novel C-C Bond Formation of Pyridine Nuclei
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Introduction of an acyl group at the α-, β-, and γ-positions of pyridine nuclei was accomplished. 2-Trimethylstannyl-pyridine and -quinoline and 1-trimethylstannylisoquinoline directly reacted with various acyl chlorides to give the corresponding 2-pyridyl, 2-quinolyl, and 1-isoquinolyl ketones, respectively.Reaction of 3-trimethylstannylpyridine, -quinoline, and -isoquinoline with acyl chlorides proceeded smoothly under catalysis by PdCl2 or PdCl2(PPh3)2 to afford the corresponding ketones in good yields.Similary, 4-pyridyl, -quinolyl, and -isoquinolyl ketones were prepared from corresponding 4-trimethylstannyl derivatives and acyl chlorides.Keywords--trimethylstannylazine; palladium-catalyzed reaction; acylation; palladium dichloride; dichlorobis(triphenylphosphine)palladium(II)
- Yamamoto, Yutaka,Yanagi, Akihiko
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p. 2003 - 2010
(2007/10/02)
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