- Copper(I)-Catalyzed Intramolecular N-N Coupling of Cyclopropyl O-Acyl Ketoximes: Synthesis of Spiro-fused Pyrazolin-5-ones
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A convenient copper-catalyzed approach has been developed for the synthesis of substituted spiro-fused pyrazolin-5-ones from readily available cyclopropyl O-acyl ketoximes via an intramolecular N N bond formation reaction. These catalytic reactions proceed in excellent yields with a broad scope.
- Zhang, Zhiguo,Li, Junlong,Huang, Guoqing,Sun, Kai,Zhang, Guisheng,Ma, Nana,Liu, Qingfeng,Liu, Tongxin
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p. 1309 - 1320
(2016/12/27)
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- Facile synthesis of furoquinoline and effects on radical-induced oxidation of DNA
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The aim of this work was to clarify the influences of the position of hydroxyl group and furo[2,3-b] moiety on the antioxidant effectiveness of quinoline. Thus, 4-methyl-2,3-dihydrofuro[2,3-b]quinolin-6-ol (PFQ), 4-methyl-2,3-dihydrofuro[2,3-b]quinolin-8-ol (OFQ), and 4-methyl-2,3- dihydrofuro[2,3-b]quinolin-7-ol (MFQ) were synthesized by a recyclization reaction of 1-acetyl-N-phenylcyclopropanecarboxamide in the presence of SnCl4 as the catalyst. The antioxidant capacities of PFQ, OFQ, and MFQ were evaluated in the experimental system of the oxidation of DNA caused by Cu2+/glutathione (GSH), ?OH, and 2,2′-azobis(2- amidinopropane hydrochloride) (AAPH). OFQ and PFQ were able to protect DNA against Cu2+/GSH- and ?OH-induced oxidation because the furo[2,3-b] moiety was beneficial for stabilizing the produced furoquinoline radical. Moreover, MFQ can decrease the oxidation rate of AAPH-induced oxidation of DNA, while PFQ and OFQ can inhibit AAPH-induced oxidation of DNA for a period. The data obtained from AAPH-induced oxidation of DNA were treated by chemical kinetic method; it was found that PFQ and OFQ can trap 1.3 and 1.5 radicals, respectively. Therefore, the hydroxyl group at different positions changed the mechanism of furoquinoline in protecting DNA against radical-induced oxidation. Graphical Abstract: Effects on Cu2+/glutathione-, ?OH-, and peroxyl radical-induced oxidation of DNA.[Figure not available: see fulltext.]
- Wang, Rui,Liu, Zai-Qun
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p. 1563 - 1569
(2013/07/26)
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- Ag-containing all-carbon 1,3-dipoles: Generation and formal cycloaddition for furo[3,2-b]-β/γ-lactams
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A new strategy for highly diastereoselective synthesis of furo[3,2-b]-β-lactams and furo[3,2-b]-γ-lactams via a novel Ag(i)-mediated intramolecular 1,3-dipolar cycloaddition of oxo-N- propargylamides, is developed and the possible mechanism of these trans
- Zhang, Zhiguo,Zhang, Qian,Ni, Zhikun,Liu, Qun
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supporting information; experimental part
p. 1269 - 1271
(2010/07/05)
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- Synthesis of polysubstituted 3-iodopyrans by electrophilic cyclization
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A variety of polysubstituted 3-iodopyrans were readily prepared in good to excellent yield under mild reaction conditions by the reaction of alkynyl carboxamides with ICl, I2, and NIS. The products obtained from this process are versatile mater
- Xie, Yong-Xin,Ya, Ze-Yi,Wang, Dan-Zhu,Wu, Lu-Yong,Qian, Bo,Liu, Xue-Yuan,Liang, Yong-Min
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scheme or table
p. 2283 - 2288
(2009/08/09)
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