- Complementary Site-Selective Halogenation of Nitrogen-Containing (Hetero)Aromatics with Superacids
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Site-selective functionalization of arenes that is complementary to classical aromatic substitution reactions remains a long-standing quest in organic synthesis. Exploiting the generation of halenium ion through oxidative process and the protonation of the nitrogen containing function in HF/SbF5, the chlorination and iodination of classically inert Csp2?H bonds of aromatic amines occurs. Furthermore, the superacid-promoted (poly)protonation of the molecules acts as a protection, favoring the late-stage selective halogenation of natural alkaloids and active pharmaceutical ingredients.
- Mamontov, Alexander,Martin-Mingot, Agnès,Métayer, Benoit,Karam, Omar,Zunino, Fabien,Bouazza, Fodil,Thibaudeau, Sébastien
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supporting information
p. 10411 - 10416
(2020/07/30)
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- Cobalt(II)-catalyzed regioselective C-H halogenation of anilides
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A cobalt-catalyzed regioselective C-H halogenation methodology is reported herein. The highlight of this work is the highly selective C-H functionalization of anilides, which results in high-yielding, versatile, and practical halogenated products. Thereby, brominations, chlorinations and iodinations of many electron-rich and electron-deficient anilides were achieved in a highly selective fashion. Mechanistic studies with respect to the pathway of the reaction are also described.
- Li, Ze-lin,Sun, Kang-kang,Cai, Chun
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supporting information
p. 5433 - 5440
(2018/08/12)
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- Imidazolium Salt Catalyzed para -Selective Halogenation of Electron-Rich Arenes
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A highly para-selective halogenation of arenes bearing coordinating groups in the presence of a dimidazolium salt as a catalyst is reported. A series of electron-rich p-haloarenes were prepared in good yields and good to excellent selectivities. We also propose a plausible mechanism for the catalytic reaction.
- Chen, Jie,Xiong, Xiaoyu,Chen, Zenghua,Huang, Jianhui
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supporting information
p. 2831 - 2834
(2015/12/18)
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- Copper-catalyzed conversion of aryl and heteroaryl bromides into the corresponding chlorides
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An efficient method for the synthesis of aryl and heteroaryl chlorides is described. The reactions of aryl and heteroaryl bromides with tetramethylammonium chloride proceeded smoothly in the presence of a copper catalyst under mild reaction conditions to produce the corresponding chlorides in satisfactory to excellent yields.
- Feng, Xiujuan,Qu, Yiping,Han, Yanlei,Yu, Xiaoqiang,Bao, Ming,Yamamoto, Yoshinori
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supporting information
p. 9468 - 9470
(2012/10/29)
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- Mild C - H halogenation of anilides and the isolation of an unusual palladium(I)-palladium(II) species
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Reducing the load: A facile palladium-catalyzed ortho-selective bromination and chlorination of anilides occurs under aerobic conditions at room temperature when N-halosuccinimides (NXS) are used in the presence of p-toluenesulfonic acid (PTSA). The orthopalladated PTSA complex is not only catalytically competent but also undergoes a reductive process to yield an unusual PdI-PdII tetramer (see structure; Pdgreen, Ored, Syellow, Cgray). Copyright
- Bedford, Robin B.,Haddow, Mairi F.,Mitchell, Charlotte J.,Webster, Ruth L.
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supporting information; experimental part
p. 5524 - 5527
(2011/07/31)
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- Solvent-free aromatic C-H functionalisation/halogenation reactions
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The solvent-free, palladium-catalysed reaction of anilides with CuCl 2 in the presence or absence of copper acetate yields ortho-chlorinated anilides in good to excellent yields, even on a large scale (100 mmol). By contrast, the equivalent reactions with copper bromide, either solvent free or in 1,2-dichloroethane, in the presence or absence of palladium, under air or inert conditions, gave the products of simple electrophilic bromination. Mechanistic studies highlighted the involvement of palladacyclic intermediates, one of which was characterised crystallographically, which undergo subsequent reaction with copper(ii) chloride to yield the chlorinated anilide products.
- Bedford, Robin B.,Engelhart, Jens U.,Haddow, Mairi F.,Mitchell, Charlotte J.,Webster, Ruth L.
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p. 10464 - 10472
(2011/01/05)
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