- The copper-catalyzed ring-opening reactions of cyclopropanes by N-fluorobenzenesulfonimide toward N-allylsulfonamides
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In this paper, we reported a copper-catalyzed ring-opening reaction of arylcyclopropanes by N-fluorobenzenesulfonimide, leading to N-allylsulfonamides in moderate to good yields. This procedure tolerated bromo, fluoro, trifluoromethyl, phenyl and alkyl groups in the phenyl, proceeding with a sequential ring-opening of arylcyclopropanes, and copper-mediated β-H elimination of alkyl radical.
- Zhou, Aijun,Shao, Ying,Chen, Fan,Qian, Peng-Cheng,Cheng, Jiang
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supporting information
(2022/01/03)
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- Imidazotetrazines as Weighable Diazomethane Surrogates for Esterifications and Cyclopropanations
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Diazomethane is one of the most versatile reagents in organic synthesis, but its utility is limited by its hazardous nature. Although alternative methods exist to perform the unique chemistry of diazomethane, these suffer from diminished reactivity and/or correspondingly harsher conditions. Herein, we describe the repurposing of imidazotetrazines (such as temozolomide, TMZ, the standard of care for glioblastoma) for use as synthetic precursors of alkyl diazonium reagents. TMZ was employed to conduct esterifications and metal-catalyzed cyclopropanations, and results show that methyl ester formation from a wide variety of substrates is especially efficient and operationally simple. TMZ is a commercially available solid that is non-explosive and non-toxic, and should find broad utility as a replacement for diazomethane.
- Svec, Riley L.,Hergenrother, Paul J.
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supporting information
p. 1857 - 1862
(2019/12/27)
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- Cyclopropanation of styrenes and stilbenes using lithiomethyl trimethylammonium triflate as methylene donor
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Lithiomethyl trimethylammonium triflate, prepared from tetramethylammonium triflate, cyclopropanates several styrenes and stilbenes with electron-donating and selected electron-withdrawing substituents efficiently. Kinetic data support a stepwise nucleophilic addition-ring closure mechanism for this methylenation. This journal is the Partner Organisations 2014.
- Sarria Toro, Juan M.,Den Hartog, Tim,Chen, Peter
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supporting information
p. 10608 - 10610
(2014/10/15)
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- Palladium-catalysed direct cross-coupling of secondary alkyllithium reagents
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Palladium-catalysed cross-coupling of secondary C(sp3) organometallic reagents has been a long-standing challenge in organic synthesis, due to the problems associated with undesired isomerisation or the formation of reduction products. Based on our recently developed catalytic C-C bond formation with organolithium reagents, herein we present a Pd-catalysed cross-coupling of secondary alkyllithium reagents with aryl and alkenyl bromides. The reaction proceeds at room temperature and on short timescales with high selectivity and yields. This methodology is also applicable to hindered aryl bromides, which are a major challenge in the field of metal catalysed cross-coupling reactions.
- Vila, Carlos,Giannerini, Massimo,Hornillos, Valentin,Fananas-Mastral, Martin,Feringa, Ben L.
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p. 1361 - 1367
(2014/03/21)
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- Facile synthesis of aryl(het)cyclopropane catalyzed by palladacycle
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Sphos (2-dicyclohexylphosphino-2′,6′-dimethoxy-1,1′- biphenyl) adduct of cyclopalladated ferrocenylimine (IIe) exhibited highly catalytic activity for the Suzuki cross-coupling reaction of cyclopropylboronic acid with aryl(het) halides with 1 mol % catalyst loading. This process was applied to both of aryl and heteroaryl halides (Br and Cl), and made the various arylcyclopropane and heteroarylcyclopropane to be easily synthesized. A variety of substituents on the aryl halides, such as alkyl, acetyl, benzoyl, ether, formyl, carboxylate, methoxy, nitro and cyano were tolerated.
- Zhang, Min,Cui, Xiuling,Chen, Xiaopei,Wang, Lianhui,Li, Jingya,Wu, Yusheng,Hou, Lifen,Wu, Yangjie
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experimental part
p. 900 - 905
(2012/02/01)
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- Cyclopropylboronic acid: Synthesis and Suzuki cross-coupling reactions
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An efficient synthesis of cyclopropylboronic acid is reported. This compound undergoes efficient Suzuki-type coupling reactions with a range of aryl and heteroarybromides.
- Wallace, Debra J.,Chen, Cheng-Yi
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p. 6987 - 6990
(2007/10/03)
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