- Design, Synthesis, and Biological Evaluation of Novel Pyrimido[4,5-b]indole Derivatives against Gram-Negative Multidrug-Resistant Pathogens
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Due to the poor permeability across Gram-negative bacterial membranes and the troublesome bacterial efflux mechanism, only a few GyrB/ParE inhibitors with potent activity against Gram-negative pathogens have been reported. Among them, pyrimido[4,5-b]indol
- Kong, Qidi,Pan, Wei,Xu, Heng,Xue, Yaru,Guo, Bin,Meng, Xin,Luo, Cheng,Wang, Ting,Zhang, Shuhua,Yang, Yushe
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supporting information
p. 8644 - 8665
(2021/06/28)
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- Catalyst-free, direct electrochemical synthesis of annulated medium-sized lactams through C-C bond cleavage
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A catalyst-free, direct electrochemical synthesis of synthetically challenging medium-sized lactams through C-C bond cleavage has been developed. In contrast to previous typical amidyl radical cyclization, this electrosynthetic approach enabled step-economical ring expansion through a unique remote amidyl migration under mild, metal- and external-oxidant-free conditions in a simple undivided cell. The strategy features unparalleled broad substrate scope with all ring sizes of (hetero)aryl-fused 8-11-membered rings and hetero atom-tethered rings, high yields, and good functional group tolerance. Our experimental and computational findings provided strong support for a SET-based reaction manifold.
- Ackermann, Lutz,Huang, Zhixing,Kuniyil, Rositha,Li, Yueheng,Ruan, Zhixiong,Xu, Zhongnan,Zhang, Chao
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supporting information
p. 1099 - 1104
(2020/03/11)
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- Direct Photocatalytic Synthesis of Medium-Sized Lactams by C?C Bond Cleavage
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Reported is a novel two-step ring-expansion strategy for expeditious synthesis of all ring sizes of synthetically challenging (hetero)aryl-fused medium-sized lactams from readily available 5–8-membered cyclic ketones. This step-economic approach features a remote radical (hetero)aryl migration from C to N under visible-light conditions. Broad substrate scope, good functional-group tolerance, high efficiency, and mild reaction conditions make this procedure very attractive. In addition, this method also provides expedient access to 13–15-membered macrolactams upon an additional one-step manipulation. Mechanistic studies indicate that the reaction involves an amidyl radical and is promoted by acid.
- Wang, Na,Gu, Qiang-Shuai,Li, Zhong-Liang,Li, Zhuang,Guo, Yu-Long,Guo, Zhen,Liu, Xin-Yuan
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supporting information
p. 14225 - 14229
(2018/10/15)
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- Synthesis of Highly Functionalized 4-Aminoquinolines
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A diverse set of highly substituted 4-aminoquinolines was synthesized from ynamides, triflic anhydride, 2-chloropyridine, and readily accessible amides in a mild one-step procedure. Diverse products: Electrophilically activated amides easily react with sulfonyl ynamides to yield a diverse range of substituted 4-aminoquinolines. The ynamides can be easily modified by Sonogashira processes or generated from dichloroenamide precursors. Any substituent can thus be introduced at the C3 position of the quinoline. 2-ClPy=2-chloropyridine, Tf2O=triflic anhydride.
- Wezeman, Tim,Zhong, Sabilla,Nieger, Martin,Br?se, Stefan
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supporting information
p. 3823 - 3827
(2016/04/05)
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- Revisiting the Synthesis of 4,6-Difluorobenzofuroxan: A Study of Its Reactivity and Access to Fluorinated Quinoxaline Oxides
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New quinoxaline 1,4-dioxide derivatives have been synthesized from novel fluorinated benzofuroxans such as 4-fluorobenzofuroxan, which is prepared for the first time. Furthermore, the preparation 4,6-difluorobenzofuroxan has been revisited because we were
- Jovené, Cyril,Jacquet, Morgane,Marrot, Jérome,Bourdreux, Flavien,Kletsky, Mikhail E.,Burov, Oleg N.,Gon?alves, Anne-Marie,Goumont, Régis
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p. 6451 - 6466
(2016/02/18)
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- Palladium-catalyzed oxidative arylalkylation of unactivated alkenes: Dual C-H bond cleavage of anilines and acetonitrile
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A palladium-catalyzed oxidative arylalkylation of unactivated alkenes involving dual C-H bond cleavage of arene and acetonitrile was developed. This reaction was promoted by pyridine as a ligand, and the ratio of palladium to pyridine is vital for this transformation. A series of nitrile-containing indolines were efficiently provided in moderate to good yields. Copyright
- Zhang, Hao,Chen, Pinhong,Liu, Guosheng
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supporting information
p. 2749 - 2752
(2013/02/22)
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- Rhodium(III)-catalyzed arene and alkene C-H bond functionalization leading to indoles and pyrroles
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Recently, the rhodium(III)-complex [Cp*RhCl2]2 1 has provided exciting opportunities for the efficient synthesis of aromatic heterocycles based on a rhodium-catalyzed C-H bond functionalization event. In the present report, the use of complexes 1 and its dicationic analogue [Cp*Rh(MeCN)3][SbF6]2 2 have been employed in the formation of indoles via the oxidative annulation of acetanilides with internal alkynes. The optimized reaction conditions allow for molecular oxygen to be used as the terminal oxidant in this process, and the reaction may be carried out under mild temperatures (60 °C). These conditions have resulted in an expanded compatibility of the reaction to include a range of new internal alkynes bearing synthetically useful functional groups in moderate to excellent yields. The applicability of the method is exemplified in an efficient synthesis of paullone 3, a tetracyclic indole derivative with established biological activity. A mechanistic investigation of the reaction, employing deuterium labeling experiments and kinetic analysis, has provided insight into issues of reactivity for both coupling partners as well as aided in the development of conditions for improved regioselectivity with respect to meta-substituted acetanilides. This reaction class has also been extended to include the synthesis of pyrroles. Catalyst 2 efficiently couples substituted enamides with internal alkynes at room temperature to form trisubstituted pyrroles in good to excellent yields. The high functional group compatibility of this reaction enables the elaboration of the pyrrole products into a variety of differentially substituted pyrroles.
- Stuart, David R.,Alsabeh, Pamela,Kuhn, Michelle,Fagnou, Keith
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supporting information; experimental part
p. 18326 - 18339
(2011/03/21)
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- Synthesis of polyfluorinated 4-phenyl-3,4-dihydroquinolin-2-ones and quinolin-2-ones via superacidic activation of N-(polyfluorophenyl)cinnamamides
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The cyclization reactions of a series of polyfluorocinnamanilides in triflic acid (CF3SO3H) yield 4-phenyl-3,4-dihydroquinolin-2-ones, which include a polyfluorinated benzene moiety as a part of the quinoline scaffold. These compounds undergo dehydrophenylation in the presence of AlCl3 to give the corresponding polyfluoroquinolin-2-ones which are converted into polyfluorinated 2-chloroquinolines on treatment with POCl3. A mechanism for the cyclization reaction presuming the intermediacy of a superelectrophilic O,C-diprotonated form of the starting material is suggested.
- Safina, Larisa Yu.,Selivanova, Galina A.,Koltunov, Konstantin Yu.,Shteingarts, Vitalij D.
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supporting information; experimental part
p. 5245 - 5247
(2009/12/06)
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