- Activator free, expeditious and eco-friendly chlorination of activated arenes by N-chloro-N-(phenylsulfonyl)benzene sulfonamide (NCBSI)
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N-Chloro-N-(phenylsulfonyl)benzene sulfonamide (NCBSI) has been explored for the first time as a chlorinating reagent for direct chlorination of various activated arenes and heterocycles without any activator. A comparative in-silico study was performed to determine the electrophilic character for NCBSI and commercially available N-chloro reagents to reveal the reactivity on a theoretical viewpoint. The reagent was prepared by an improved method avoiding the use of hazardous t-butyl hypochlorite. This reagent was proved to be very reactive compared to other N-chloro reagents. The precursor of the reagent N-(phenylsulfonyl)benzene sulfonamide was recovered from aqueous spent, which can be recycled to synthesize NCBSI. The eco-friendly protocol was equally applicable for the synthesis of industrially important chloroxylenol as an antibacterial agent.
- Misal, Balu,Palav, Amey,Ganwir, Prerna,Chaturbhuj, Ganesh
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supporting information
(2021/01/04)
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- Synthesis of 3-halogenated 2,3′-biindoles by a copper-mediated 2,3-difunctionalization of indoles
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A copper-mediated 2,3-difunctionalization of indoles to afford 3-halogenated 2,3′-biindoles is described herein. The protocol uses readily available feedstocks and a naturally abundant copper catalyst system, which allows the regioselective formation of C-C and C-X (X = Cl & Br) bonds in one single operation. Here the copper metal salt serves not only as a catalyst but also as a reactant to provide the source of halogen. This operationally simple procedure avoids the utilization of environmentally unfriendly reagents and displays good functional group compatibility. Noteworthily, the introduction of halogen into molecules would offer great potential for further chemical transformations. This journal is
- Gu, Xiaoting,Liang, Taoyuan,Wei, Wanxing,Zhang, Xiaoxiang,Zhang, Yingying,Zhang, Zhuan
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supporting information
p. 10403 - 10407
(2021/12/17)
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- Sulfoxide-Promoted Chlorination of Indoles and Electron-Rich Arenes with Chlorine as Nucleophile
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An efficient chlorination of indoles and electron-rich arenes with chlorine anion as nucleophile is described. With the use of ethyl phenyl sulfoxide as the promoter, the reaction went smoothly under metal-free and mild conditions. Various indoles and electron-rich arenes are converted into the corresponding chlorinated compounds in moderate to excellent yields. A plausible interrupted Pummerer reaction mechanism was proposed without the oxidation of chloride anion. In addition, the byproduct thioether could be easily converted to the starting material sulfoxide just by a simple oxidation reaction. (Figure presented.).
- Ji, Yuan-Zhao,Li, Hui-Jing,Wang, Yi-Ruo,Wu, Yan-Chao,Zhang, Zheng-Yan
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supporting information
(2020/02/05)
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- Atroposelective Haloamidation of Indoles with Amino Acid Derivatives and Hypohalides
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An atroposelective coupling of indoles with chiral amino acid-based sulfonamides mediated by hypohalides is described. A series of 2-amido-3-haloindoles with a C-N chiral axis are delivered using this strategy. The C3 halogen atoms can facilitate further
- Li, Zhaojie,Tang, Menghan,Hu, Chenyang,Yu, Shouyun
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supporting information
p. 8819 - 8823
(2019/11/11)
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- Controllable synthesis of 3-chloro- and 3,3-dichloro-2-oxindoles via hypervalent iodine-mediated chlorooxidation
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An efficient and controllable protocol for the synthesis of 3-chloro- and 3,3-dichloro-2-oxindoles has been developed via hypervalent iodine-promoted chlorooxidation. By using two equivalents of 1-chloro-1,2-benziodoxol-3-(1H)-one, a wide range of indoles
- Jiang, Xinpeng,Yang, Liechao,Yang, Wenlong,Zhu, Yu,Fang, Liyun,Yu, Chuanming
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supporting information
p. 6920 - 6924
(2019/07/22)
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- Visible-Light-Induced Direct Oxidative C?H Amidation of Heteroarenes with Sulfonamides
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A direct oxidative C?H amidation of heteroarenes with sulfonamides via nitrogen-centered radicals has been achieved. Nitrogen-centered radicals are directly generated from oxidative cleavage of N?H bonds under visible-light photoredox catalysis. Sulfonami
- Tong, Kun,Liu, Xiaodong,Zhang, Yan,Yu, Shouyun
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supporting information
p. 15669 - 15673
(2016/10/25)
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- Simple and efficient procedures for selective preparation of 3-haloindoles and 2,3-dihaloindoles by using 1,3-dibromo-5,5-dimethylhydantoin and 1,3-dichloro-5,5-dimethylhydantoin
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Simple and efficient synthetic procedures for the selective preparation of 3-bromo/3-chloroindoles and 2,3-dibromo/2,3-dichloroindoles by using 1,3-dibromo-5,5-dimethylhydantoin (DBDMH) and 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) were developed. Using 1,4-dioxane as the solvent, a variety of indoles, treated with 0.55 equiv DBDMH/DCDMH, afford the corresponding 3-bromo/3-chloroindoles selectively in 82-99% yield. In 1,2-dichloroethane (DCE), a series of 2,3-dichloro/2,3-dibromoindoles were selectively obtained in 84-95% yield by treating with DBDMH/DCDMH. All the processes do not need extra catalysts, dry solvents, or harsh reaction conditions.
- Yan, Jianwei,Ni, Tianjun,Yan, Fulin
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supporting information
p. 1096 - 1098
(2015/02/19)
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- A practical lewis base catalyzed electrophilic chlorination of arenes and heterocycles
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A mild phosphine sulfide catalyzed electrophilic halogenation of arenes and heterocycles that utilizes inexpensive and readily available N-halosuccinimides is disclosed. This methodology is shown to efficiently chlorinate diverse aromatics, including simple arenes such as anthracene, and heterocycles such as indoles, pyrrolopyrimidines, and imidazoles. Arenes with Lewis acidic moieties also proved amenable, underscoring the mild nature of this chemistry. Lewis base catalysis was also found to improve several diverse aromatic brominations and iodinations.
- Maddox, Sean M.,Nalbandian, Christopher J.,Smith, Davis E.,Gustafson, Jeffrey L.
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supporting information
p. 1042 - 1045
(2015/03/30)
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- Pd(II)-catalyzed bromo- and chlorodecarboxylation of electron-rich arenecarboxylic acids
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A bromo- and chlorodecarboxylation of various aromatic carboxylic acids catalyzed by Pd(II) has been developed in this work. A series of electron-rich arenecarboxylic acids gave the corresponding decarboxylative monohalogenation products under the typical reaction conditions.
- Peng, Xuefeng,Shao, Xiang-Feng,Liu, Zhong-Quan
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supporting information
p. 3079 - 3081
(2013/07/11)
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- 2,4,6-Tris[(4-dichloroiodo)phenoxy)]-1,3,5-triazine as a new recyclable hypervalent iodine(III) reagent for chlorination and oxidation reactions
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The synthesis of 2,4,6-tris[(4-dichloroiodo)phenoxy)]-1,3,5-triazine, as a new recyclable nonpolymeric analogue of (dichloroiodo)benzene, is achieved in two steps using 2,4,6-trichloro-1,3,5-triazine and 4-iodophenol. The application of 2,4,6-tris[(4-dichloroiodo)phenoxy)]-1,3,5-triazine for the chlorination reaction of various activated arenes, olefin, and 1,3-diketone is demonstrated. The reagent 2,4,6-tris[(4-dichloroiodo)phenoxy)]-1,3,5-triazine can be applied also for the oxidative synthesis of 1,3,4-oxadiazoles and 1,2,4-thiadiazoles under mild conditions in excellent yields. The recyclability of the 2,4,6-tris[(4-dichloroiodo)phenoxy)]-1,3,5-triazine was possible owing to the facile recovery and reuse of the coproduced 2,4,6-tris(4-iodophenoxy)-1,3,5- triazine from the reaction mixture due to its practical insolubility in methanol. Georg Thieme Verlag Stuttgart, New York.
- Thorat, Prerana B.,Bhong, Bhagyashree Y.,Karade, Nandkishor Y.
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supporting information
p. 2061 - 2066
(2013/10/21)
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- Chemistry of polyhalogenated nitrobutadienes, part 11: Ipso-formylation of 2-chlorothiophenes under Vilsmeier-Haack conditions
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The regioselective ipso-formylation of electron-rich, 3,4-push-pull- substituted 2-chlorothiophenes under Vilsmeier-Haack conditions was performed in good yields. The synthetic scope of this new reaction was explored using various halothiophenes, chloroanilines, and 1-methyl-3-chloroindole. In comparison with their structural C-H analogs the chlorinated thiophenes, anilines, and the indole proved to be less reactive toward electrophilic attack by chloromethyleniminium salts.
- Vogt, Eva-Janina,Zapol'skii, Viktor A.,Nutz, Eva,Kaufmann, Dieter E.
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experimental part
p. 285 - 294
(2012/07/14)
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- Room-temperature Suzuki-Miyaura coupling of heteroaryl chlorides and tosylates
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Suzuki-Miyaura coupling of heteroaryls is an important method for the preparation of compound libraries for medicinal chemistry and materials research. Although many catalysts have been developed, none of them have been generally applicable to the coupling reactions of heteroaryl chlorides and tosylates at room temperature. We discovered that a catalyst combination of Pd(OAc)2 and XPhos (2-dicyclohexylphosphanyl-2',4',6'- triisopropylbiphenyl) could efficiently catalyze these couplings. Besides the choice of catalyst, the use of hydroxide bases in an aqueous alcoholic solvent was essential for fast couplings. These conditions promoted fast release of active catalyst (XPhos)Pd0, and accelerated the transmetalation in the catalytic cycle. Most of the major families of heteroaryl chlorides (31 examples) and tosylates (17 examples) reached full conversion within minutes to hours at room temperature. The method could be easily scaled up for gram-scale synthesis. Furthermore, we examined the relative reactivity of coupling partners in whole reactions. Electron-rich heteroaryl chlorides and tosylates reacted more slowly than electron-deficient ones, in the order of indole, pyrrole furan, thiophene > pyridine. Similarly, electron-deficient arylboronic acids were less reactive than electron-neutral and electron-rich ones. The reactivity trends from this study can help to choose appropriate coupling partners for Suzuki reactions.
- Yang, Junfeng,Liu, Sijia,Zheng, Jian-Feng,Zhou, Jianrong
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supporting information
p. 6248 - 6259,12
(2020/09/16)
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- Electrophilicities of α-chlorinating agents used in organocatalysis
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Kinetics of the reactions of the chlorinating agents 1a-c with π-nucleophiles have been studied to include these compounds in our comprehensive electrophilicity scale.
- Duan, Xin-Hua,Mayr, Herbert
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supporting information; experimental part
p. 2238 - 2241
(2010/08/05)
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- Modulating reactivity and diverting selectivity in palladium-catalyzed heteroaromatic direct arylation through the use of a chloride activating/blocking group
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(Chemical Equation Presented) Through the introduction of an aryl chloride substituent, the selectivity of palladium-catalyzed direct arylation may be diverted to provide alternative regioisomeric products in high yields. In cases where low reactivity is typically observed, the presence of the carbon-chlorine bond can serve to enhance reactivity and provide superior outcomes. From a strategic perspective, the C-Cl bond is easily introduced and can be employed in a variety of subsequent transformations to provide a wealth of highly functionalized heterocycles with minimal substrate preactivation. The impact of the C-Cl functional group on direct arylation reactivity has also been evaluated mechanistically, and the observed reactivity profiles correlate very well with that predicted by a concerted metalation-deprotonation pathway.
- Liegault, Benoit,Petrov, Ivan,Gorelsky, Serge I.,Fagnou, Keith
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supporting information; experimental part
p. 1047 - 1060
(2010/04/04)
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- Halogenation of indoles with copper(II) halides: Selective synthesis of 2-halo-, 3-halo-, and 2,3-dibromoindoles
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A simple and selective protocol for the halogenation of indoles with copper(II) bromide or chloride to synthesize 2-halo-, 3-halo-, and 2,3-dibromoindoles was developed. It was found that both base and water could be used as switches for the selectivity of the halogenation reactions. In the presence of copper(II) halide and sodium hydroxide, 3-haloindoles were obtained as the major products, whereas the selectivity was shifted toward 2,3-dihaloindoles when water was added instead of sodium hydroxide. Moreover, 2-halogenations of 3-substituted indoles were also performed successfully in moderate to good yields under the standard conditions. Georg Thieme Verlag Stuttgart.
- Tang, Shi,Li, Jin-Heng,Xie, Ye-Xiang,Wang, Nai-Xing
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p. 1535 - 1541
(2008/02/08)
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- One-step syntheses of pyrrolo- and indolo-1,2,5-thiadiazoles and pyrrolobis[1,2,5]thiadiazoles
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Treatment of the 2,3-unsubstituted pyrrole 2 and indoles 7 with trithiazyl trichloride 1 in hot tetrachloromethane gives the 2,3-fused 1,2,5-thiadiazolo derivatives 3 and 8.2,3,4,5-Unsubstituted pyrroles 4 are similarly converted directly into the pyrrolobis(thiadiazoles) 6, without detection of the presumed, highly reactive, bicyclic intermediate 5. This ring fusion process is not prevented by the presence of bromine, chlorine, a carboxylic acid or carboxylic ester group at the α- or β-positions; indeed prior substitution by bromine or chlorine results in faster and cleaner reactions with trithiazyl trichloride to give the fused systems 3, 6 and 8 in high yield. Possible mechanisms are proposed to explain these results.
- Duan, Xiao-Guang,Rees, Charles W.
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p. 2695 - 2699
(2007/10/03)
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- N-METHYL LITHIATION OF N-METHYLINDOLES DIRECTED BY α-AMINO ALKOXIDES
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A novel N-methyl lithiation-alkylation of an α-amino alkoxide derived from 3-chloro-N-methylindole-2-carboxaldehyde is described.
- Comins, Daniel L.,Killpack, Michael O.
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p. 4337 - 4340
(2007/10/02)
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