- AROMATIC IODINATION BY POSITIVE IODINE ACTIVE SPECIES GENERATED BY ANODIC OXIDATION IN TRIMETHYL ORTHOFORMATE
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Anodic oxidation of iodine in trimethyl orthoformate afforded a solution of positive iodine active species which brought about more selective aromatic iodination than the hitherto known other methods.
- Shono, Tatsuya,Matsumura, Yoshihiro,Katoh, Susumu,Ikeda, Kaoru,Kamada, Tohru
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- Generation of Organozinc Reagents from Arylsulfonium Salts Using a Nickel Catalyst and Zinc Dust
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Readily available aryldimethylsulfonium triflates react with zinc powder under nickel catalysis via the selective cleavage of the sp2-hybridized carbon-sulfur bond to produce salt-free arylzinc triflates under mild conditions. This zincation displays superb chemoselectivity and thus represents a protocol that is complementary or orthogonal to existing methods. The generated arylzinc reagents show both high reactivity and chemoselectivity in palladium-catalyzed and copper-mediated cross-coupling reactions.
- Yamada, Kodai,Yanagi, Tomoyuki,Yorimitsu, Hideki
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p. 9712 - 9718
(2021/01/09)
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- A palladium-catalyzed C-H functionalization route to ketones: Via the oxidative coupling of arenes with carbon monoxide
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We describe the development of a new palladium-catalyzed method to generate ketones via the oxidative coupling of two arenes and CO. This transformation is catalyzed by simple palladium salts, and is postulated to proceed via the conversion of arenes into high energy aroyl triflate electrophiles. Exploiting the latter can also allow the synthesis of unsymmetrical ketones from two different arenes.
- Arndtsen, Bruce A.,Kinney, R. Garrison,Levesque, Taleah M.
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p. 3104 - 3109
(2020/03/27)
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- Generation of Organozinc Reagents by Nickel Diazadiene Complex Catalyzed Zinc Insertion into Aryl Sulfonates
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The generation of arylzinc reagents (ArZnX) by direct insertion of zinc into the C?X bond of ArX electrophiles has typically been restricted to iodides and bromides. The insertions of zinc dust into the C?O bonds of various aryl sulfonates (tosylates, mesylates, triflates, sulfamates), or into the C?X bonds of other moderate electrophiles (X=Cl, SMe) are catalyzed by a simple NiCl2–1,4-diazadiene catalyst system, in which 1,4-diazadiene (DAD) stands for diacetyl diimines, phenanthroline, bipyridine and related ligands. Catalytic zincation in DMF or NMP solution at room temperature now provides arylzinc sulfonates, which undergo typical catalytic cross-coupling or electrophilic substitution reactions.
- Klein, Philippe,Lechner, Vivien Denise,Schimmel, Tanja,Hintermann, Lukas
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p. 176 - 180
(2019/12/11)
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- Synthesis of pure blue emissive poly(2,7-carbazole)s anchored by electron donor pendant
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Three novel poly(2,7-carbazole)s having hole injection and transporting pendent moieties of carbazole and triphenylamine at the N-position were synthesized for achieving pure blue electroluminescence. The N-pendants in the polymers correspond to N-phenylcarbazol-2-yl (P1), N,N-diphenylamino-N-phenylcarabazol-2-yl (P2), and 4-phenyl having a hydrocarbon chain with a triphenylamine terminal (P3), respectively. Electronic, optical, and electroluminescence properties of these polymers were compared with those of a poly(2,7-carbazole) directly connected with triphenylamine at the N-position (P0) having an aggregation-induced emissive property. The photoluminescence (PL) spectra suggested that they could emit in the region of blue light in the film state. Especially, P2 that has the fixed and large diphenylaminocarbazolyl pendant showed a deep-blue fluorescence with CIE(x, y) = (0.15, 0.07). The P0, P2, and P3 based light emitting diode devices showed maximum electroluminescence wavelengths in the range of 430–450 nm. The P2 device showed pure blue emission (CIE[x, y] = [0.18, 0.16]), high luminance (1130 cd/m2) and current density (628 mA/cm2) at 8 V, whereas low-energy emissions around 500–600 nm were emerged at higher than 9 V. The P0 and P3 devices also showed a blue electroluminescence in the range of 8–11 V, but their luminance and efficiency were low.
- Inada, Takashi,Shinnai, Toshinobu,Kijima, Masashi
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p. 2526 - 2534
(2019/11/03)
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- Disulfide-Catalyzed Iodination of Electron-Rich Aromatic Compounds
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Herein, a disulfide-catalyzed electrophilic iodination of aromatic compounds using 1,3-diiodo-5,5-dimethylhydantoin (DIH) has been developed. The disulfide activates DIH as a Lewis base to promote the iodination reaction in acetonitrile under mild conditions. This system is applicable to a wide range of electron-rich aromatic compounds, including acetanilide, anisole, imidazole, and pyrazole derivatives.
- Iida, Keisuke,Ishida, Shunsuke,Watanabe, Takamichi,Arai, Takayoshi
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- Disulfide-Catalyzed Iodination of Electron-Rich Aromatic Compounds
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Herein, a disulfide-catalyzed electrophilic iodination of aromatic compounds using 1,3-diiodo-5,5-dimethylhydantoin (DIH) has been developed. The disulfide activates DIH as a Lewis base to promote the iodination reaction in acetonitrile under mild conditions. This system is applicable to a wide range of electron-rich aromatic compounds, including acetanilide, anisole, imidazole, and pyrazole derivatives.
- Iida, Keisuke,Ishida, Shunsuke,Watanabe, Takamichi,Arai, Takayoshi
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p. 7411 - 7417
(2019/06/18)
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- One of iodinated aromatic ring by iodine chloride in hydrochloric acid (by machine translation)
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[Problem] to one iodine chloride is used, and, stably iodinated aromatic compound can be iodinated aromatic compound production. [Solution] water containing one iodine chloride hydrogen chloride, iodine chloride content of 30% by mass of the first mass % -70, 3 mass % -20 mass % aqueous solution of hydrogen chloride content in the preparing step, a process for preparing an aromatic compound as the reaction substrate, the reaction substrate as an aqueous solution of the mixture of aromatic compounds, as the reaction substrate of one iodine chloride by reacting an aromatic compound, iodinated aromatic compound obtained in the step, the iodinated aromatic compound. [Drawing] no (by machine translation)
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Paragraph 0072-0076
(2019/09/10)
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- Visible-Light-Photosensitized Aryl and Alkyl Decarboxylative Functionalization Reactions
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Despite significant progress in aliphatic decarboxylation, an efficient and general protocol for radical aromatic decarboxylation has lagged far behind. Herein, we describe a general strategy for rapid access to both aryl and alkyl radicals by photosensitized decarboxylation of the corresponding carboxylic acids esters followed by their successive use in divergent carbon–heteroatom and carbon–carbon bond-forming reactions. Identification of a suitable activator for carboxylic acids is the key to bypass a competing single-electron-transfer mechanism and “switch on” an energy-transfer-mediated homolysis of unsymmetrical σ-bonds for a concerted fragmentation/decarboxylation process.
- Patra, Tuhin,Mukherjee, Satobhisha,Ma, Jiajia,Strieth-Kalthoff, Felix,Glorius, Frank
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p. 10514 - 10520
(2019/07/12)
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- Metathesis-active ligands enable a catalytic functional group metathesis between aroyl chlorides and aryl iodides
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Current methods for functional group interconversion have, for the most part, relied on relatively strong driving forces which often require highly reactive reagents to generate irreversibly a desired product in high yield and selectivity. These approaches generally prevent the use of the same catalytic strategy to perform the reverse reaction. Here we describe a catalytic functional group metathesis approach to interconvert, under CO-free conditions, two synthetically important classes of electrophiles that are often employed in the preparation of pharmaceuticals and agrochemicals—aroyl chlorides (ArCOCl) and aryl iodides (ArI). Our reaction design relies on the implementation of a key reversible ligand C–P bond cleavage event, which enables a non-innocent, metathesis-active phosphine ligand to mediate a rapid aryl group transfer between the two different electrophiles. Beyond enabling a practical and safer approach to the interconversion of ArCOCl and ArI, this type of ligand non-innocence provides a blueprint for the development of a broad range of functional group metathesis reactions employing synthetically relevant aryl electrophiles.
- Lee, Yong Ho,Morandi, Bill
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p. 1016 - 1022
(2018/09/06)
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- Synthesis of phenols and aryl silyl ethers via arylation of complementary hydroxide surrogates
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Two transition-metal-free methods to access substituted phenols via the arylation of silanols or hydrogen peroxide with diaryliodonium salts are presented. The complementary reactivity of the two nucleophiles allows synthesis of a broad range of phenols without competing aryne formation, as illustrated by the synthesis of the anesthetic Propofol. Furthermore, silyl-protected phenols can easily be obtained, which are suitable for further transformations.
- Reitti, Marcus,Gurubrahamam, Ramani,Walther, Melanie,Lindstedt, Erik,Olofsson, Berit
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supporting information
p. 1785 - 1788
(2018/04/14)
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- Simple and Efficient Generation of Aryl Radicals from Aryl Triflates: Synthesis of Aryl Boronates and Aryl Iodides at Room Temperature
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Despite the wide use of aryl radicals in organic synthesis, current methods to prepare them from aryl halides, carboxylic acids, boronic acids, and diazonium salts suffer from limitations. Aryl triflates, easily obtained from phenols, are promising aryl radical progenitors but remain elusive in this regard. Inspired by the single electron transfer process for aryl halides to access aryl radicals, we developed a simple and efficient protocol to convert aryl triflates to aryl radicals. Our success lies in exploiting sodium iodide as the soft electron donor assisted by light. This strategy enables the scalable synthesis of two types of important organic molecules, i.e., aryl boronates and aryl iodides, in good to high yields, with broad functional group compatibility in a transition-metal-free manner at room temperature. This protocol is anticipated to find potential applications in other aryl-radical-involved reactions by using aryl triflates as aryl radical precursors.
- Liu, Wenbo,Yang, Xiaobo,Gao, Yang,Li, Chao-Jun
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supporting information
p. 8621 - 8627
(2017/07/06)
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- Copper-mediated aerobic iodination and perfluoroalkylation of boronic acids with (CF3)2CFI at room temperature
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The copper-mediated aerobic reactions between the branched (CF3)2CFI and boronic acids (R-B(OH)2) are described. Different from the linear perfluoroalkyl analogs CF3(CF2)nI (n?=?2, 3, 5, 7), (CF3)2CFI reacting with R-B(OH)2at room temperature under air in the presence of catalytic Cu powder provided exclusively the corresponding iodides (R-I), while the aerobic reactions of arylboronic acids with (CF3)2CFI at room temperature in the presence of Cu(OAc)2gave the perfluoroalkylation products (R-CF(CF3)2) in acceptable to moderate yields. The iodination reaction could be further promoted by hydroquinone, the addition of which improved the oxidation ability of (CF3)2CFI and provided the ipso-iodination products in high yields. The perfluoroalkylation was facilitated by the copper carboxylates since the addition of these salts into the reaction mixtures could successfully give rise to Ar-CF(CF3)2.
- Liu, Xi-Hai,Leng, Jing,Jia, Su-Jiao,Hao, Jian-Hong,Zhang, Fanglin,Qin, Hua-Li,Zhang, Cheng-Pan
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- Practical and efficient ipso-iodination of arylboronic acids via KF/I2 system
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A facile and effective iododeboronation of variously substituted aryl and heteroarylboronic acids through activation and subsequent ipso-introduction of iodine is presented. The use of KF and I2 at 80 °C in 1,4-dioxane furnishes iodinated compounds in high yields.
- Tramutola, Francesco,Chiummiento, Lucia,Funicello, Maria,Lupattelli, Paolo
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p. 1122 - 1123
(2015/02/19)
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- Rapid and efficient copper-catalyzed finkelstein reaction of (hetero)aromatics under continuous-flow conditions
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A general, rapid, and efficient method for the copper-catalyzed Finkelstein reaction of (hetero)aromatics has been developed using continuous flow to generate a variety of aryl iodides. The described method can tolerate a broad spectrum of functional groups, including N-H and O-H groups. Additionally, in lieu of isolation, the aryl iodide solutions were used in two distinct multistep continuous-flow processes (amidation and Mg-I exchange/nucleophilic addition) to demonstrate the flexibility of this method.
- Chen, Mao,Ichikawa, Saki,Buchwald, Stephen L.
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supporting information
p. 263 - 266
(2015/02/05)
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- Efficient and direct iodination of alkyl benzenes using polymer/HIO4 and I2 under mild condition
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An efficient and rapid method has been found for the iodination of aromatic compounds using iodine and polymer-supported periodic acid (PSPIA) as an oxidant under mild aprotic conditions. The reagent after the completion of the reaction was easily removed by filtration and was regenerated for further use. This method has some advantages such as: mild reaction conditions, straight forward procedure, inexpensive method, high yields and one-pot conversion.
- Bahrami-Nasab, Sepideh,Nazifi, S. Mohamad Reza,Pourali, Ali Reza
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p. 305 - 308
(2014/06/24)
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- Metal-free synthesis of aryl ethers in water
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The first arylation of allylic and benzylic alcohols with diaryliodonium salts is reported. The reaction yields alkyl aryl ethers under mild and metal-free conditions. Phenols are arylated to diaryl ethers in good to excellent yields. The reaction employs diaryliodonium salts and sodium hydroxide in water at low temperature, and excess amounts of the coupling partners are avoided.
- Lindstedt, Erik,Ghosh, Raju,Olofsson, Berit
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p. 6070 - 6073
(2014/01/06)
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- A simple and effective copper catalyst for the conversion of arylboronic acids to aryl iodides at room temperature
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Simple Cu(NO3)2·3H2O was demonstrated to be of ability to catalyze the conversion of arylboronic acids to aryl iodides at room temperature. Compared with the previous copper-catalyzed method, the present procedure avoids the use of the ligand, the oxidant as well as the heating condition.
- Ren, Yun-Lai,Tian, Xin-Zhe,Dong, Chuanhua,Zhao, Shuang,Wang, Jianji,Yan, Mengjie,Qi, Xiaoguang,Liu, Guihua
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- Visible light-mediated direct arylation of arenes and heteroarenes using diaryliodonium salts in the presence and absence of a photocatalyst
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Diaryliodonium salts have been used as aryl radical sources under visible light-mediated photoredox catalysis. Benzene and a range of heteroarenes are arylated with Ar2I+ in the presence of [Ir(ppy)2(bpy)] PF6 upon irradiation with visible light. When pyrroles are used, the arylation proceeds in the absence of a photoredox catalyst. Both processes are initiated by photoinduced single-electron-transfer to Ar2I+, generating aryl radicals.
- Tobisu, Mamoru,Furukawa, Takayuki,Chatani, Naoto
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supporting information
p. 1203 - 1205
(2013/10/22)
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- Trialkyl phosphites and diaryliodonium salts as co-initiators in a system for radical-promoted visible-light-induced cationic polymerization(1)
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Trialkyl phosphites ((RO)3P) can act as co-initiators for the diaryliodonium-induced cationic polymerization of cyclohexene oxide (CHO) or THF. A radical initiation step is also required, consistent with the essential role of a radical chain reaction of the phosphite with the iodonium salt to form polymerization-starting aryltrialkoxyphosphonium salts (ArP+(OR) 3). We used the visible photolysis of phenylazoisobutyronitrile (PAIBN) as the radical initiation step. The presence of multiple fluorine substituents on the phosphite, as in tris(2,2,2-trifluoroethyl) phosphite (TFP), allows polymerization to proceed with a minimal amount of chain transfer from nucleophilic attack by the phosphite. In a typical experiment, a CHO solution of bis(4-tert-butylphenyl)iodonium hexafluorophosphate (0.05 M), TFP (0.1 M), and PAIBN (0.02 M) was illuminated with a 65-W compact fluorescent bulb for 1 h, resulting in a 78% conversion to poly(cyclohexene oxide) with an average molecular weight (MW) of 25000. We also used competition experiments to determine approximate rate constants for reactions of phenyl radicals with CHO (k = 2 × 106 M-1 s-1) and with TFP (k = 2 × 108 M-1 s-1).
- Nalli, Thomas W.,Stanek, Lee G.,Molenaar, Rebekka H.,Weidell, Krysia L.,Meyer, Justin P.,Johnson, Brandon R.,Steckler, Timothy T.,Wackerly, Jay Wm.,Studler, Missy Jo,Vickerman, Kevin L.,Klankowski, Stephen A.
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p. 3561 - 3569
(2013/06/04)
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- Halodeboronation of organotrifluoroborates using tetrabutylammonium tribromide or cesium triiodide
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Halodeboronation of organotrifluoroborates using commercially available tetrabutylammonium tribromide (TBATB) or cesium triiodide in aqueous medium is reported. The mild, transition metal-free method has proven to be tolerant of a wide range of functional groups. High regio- and chemoselectivity are observed. Two synthetic routes to (Z)-dibromoalkenes from alkynes, through stereodefined (Z)-2-bromoalkenyltrifluoroborates and (Z)-1,2-bis(boryl) alkenyltrifluoroborates, have been developed using the TBATB mediated bromodeboronation as the key step.
- Yao, Min-Liang,Kabalka, George W.,Blevins, David W.,Reddy, Marepally Srinivasa,Yong, Li
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experimental part
p. 3738 - 3743
(2012/06/30)
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- Ruthenium-catalyzed transformation of aryl and alkenyl triflates to halides
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Aryl triflates were transformed to aryl bromides/iodides simply by treating them with LiBr/NaI and [Cp*Ru(MeCN)3]OTf. The ruthenium complex also catalyzed the transformation of alkenyl sulfonates and phosphates to alkenyl halides under mild conditions. Aryl and alkenyl triflates undergo oxidative addition to a ruthenium(II) complex to form η'1- arylruthenium and 1-ruthenacyclopropene intermediates, respectively, which are transformed to the corresponding halides.
- Imazaki, Yusuke,Shirakawa, Eiji,Ueno, Ryota,Hayashi, Tamio
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supporting information
p. 14760 - 14763
(2012/11/07)
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- Cobalt-catalyzed preparation of arylindium reagents from aryl and heteroaryl bromides
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A cobalt-bathophenanthroline catalyst has been developed for the direct preparation of a variety of arylindium reagents from the corresponding aryl and heteroaryl bromides in the presence of indium metal and lithium chloride. The thus-formed arylindium reagents undergo efficient palladium-catalyzed cross-coupling reactions with aryl iodides, tolerating various functional groups including hydroxy and free amino groups.
- Adak, Laksmikanta,Yoshikai, Naohiko
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experimental part
p. 7563 - 7568
(2011/11/12)
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- METHOD OF PRODUCING IODIZING AGENT, AND METHOD OF PRODUCING AROMATIC IODINE COMPOUND
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A method of the present invention, for producing an iodizing agent, includes the step of electrolyzing iodine molecules in a solution by using an acid as a supporting electrolyte. This realizes (i) a method of producing an iodine cation suitable for use as an iodizing agent that does not require a sophisticated separation operation after iodizing reaction is completed, and (ii) an electrolyte used in the method. Further, a method of the present invention, for producing an aromatic iodine compound, includes the step of causing an iodizing agent, and an aromatic compound whose nucleus has one or more substituent groups and two or more hydrogen atoms, to react with each other under the presence of a certain ether compound. This realizes such a method of producing an aromatic iodine compound that position selectivity in iodizing reaction of an aromatic compound is improved.
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Page/Page column 10
(2010/05/13)
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- Non-catalytic conversion of C-F bonds of benzotrifluorides to C-C bonds using organoaluminium reagents
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A facile method for the conversion of C-F bonds of benzotrifluorides to C-C bonds has been developed using aluminium reagents in the absence of catalysts.
- Terao, Jun,Nakamura, Misaki,Kambe, Nobuaki
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supporting information; experimental part
p. 6011 - 6013
(2010/11/16)
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- Copper-catalyzed arene C-H bond cross-coupling
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A highly regioselective, one-pot sequential iodination-copper-catalyzed cross-coupling of arene C-H bonds has been developed affording an efficient method for biaryl synthesis.
- Do, Hien-Quang,Daugulis, Olafs
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supporting information; experimental part
p. 6433 - 6435
(2010/03/04)
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- Halo- and azidodediazoniation of arenediazonium tetrafluoroborates with trimethylsilyl halides and trimethylsilyl azide and Sandmeyer-type bromodediazoniation with Cu(I)Br in [BMIM][PF6] ionic liquid
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(Chemical Equation Presented) Reaction of [ArN2][BF4] salts immobilized in [BMIM][PF6] ionic liquid (IL) with TMSX (X = I, Br) and TMSN3 represents an efficient method for the preparation of iodo-, bromo-, and azido-derivatives via dediazoniation. The reactions can also be effected starting with ArNH2 by in situ diazotization with [NO][BF4] followed by reaction with TMSX or TMSN3. Depending on the substituents on the benzenediazonium cation, competing fluorodediazoniation (ArF formation) and hydrodediazoniation (ArH formation) were observed. Dediazoniation with TMSN3 and with TMSI generally gave the highest chemoselectivity toward ArN3 and ArI formation. The IL was recycled and reused up to 5 times with no appreciable decrease in the conversions. Multinuclear NMR monitoring of the interaction of [ArN 2][BF4]/TMSX, [BMIM][PF6]/TMSX, and [BMIM][PF6]/TMSX/[ArN2][BF4] indicated that TMSF is formed primarily via [ArN2][BF4]/ TMSX, generating [ArN2][X] in situ, which gives ArX on dediazoniation. Competing formation of ArF in Sandmeyer-type bromodediazoniation of [ArN 2][BF4] with Cu(I)Br immobilized in the IL points to significant involvement of heterolytic dediazoniation.
- Hubbard, Abigail,Okazaki, Takao,Laali, Kenneth K.
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p. 316 - 319
(2008/09/17)
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- Sulfur contamination due to quenching of halogenation reactions with sodium thiosulfate: Resolution of process problems via improved quench protocols
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Many metal-mediated cross-couplings involve the use of organic halides, which are usually accessed by halogenation reactions. Cross-couplings are sensitive to the presence of impurities in the halides. This paper describes the origin of one such problematic impurity (sulfur) during the synthesis of organic halides and proposes alternatives to minimize or eliminate its formation.
- Xiang, Yanqiao,Caron, Pierre-Yves,Lillie, Brett M.,Vaidyanathan, Rajappa
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p. 116 - 119
(2012/12/31)
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- A novel phenothiazine derivative for application in high performance red emitting electroluminescent device
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The new red emitting materials based on phenothiazine and DCM were synthesized by Knoevenagel condensation following Vilsmeyer-Haack formulation. The obtained materials showed good thermal stability and amorphous property. The ITO/CuPc/NPB/Alq 3 :KSR-1 (0
- Kim, Yun-Hi,Kim, Hyung-Sun,Lee, Kwang-Hoi,Kwon, Soon-Ki,Kim, Sung-Han
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p. 257 - 263
(2007/10/03)
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- Progressive direct iodination of sterically hindered alkyl substituted benzenes
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Benzene derivatives bearing at least one bulky alkyl group (i-Pr or t-Bu) were selectively and effectively iodinated using elemental iodine activated, by 1-(chloromethyl)-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate) (Selectfluor, F-TED
- Stavber, Stojan,Kralj, Petra,Zupan, Marko
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p. 1513 - 1518
(2007/10/03)
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- Reactivity of aryl and vinyl radicals: Abstraction of hydrogen atom or reaction with a nucleophile
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The reactivities of aryl and vinyl radicals, two fundamental transient intermediates, have been investigated with respect to two elementary processes: H-atom abstraction and reaction with a nucleophile (Y-, in the SRN1 reaction). The radicals of interest were generated from haloarene or haloethene precursors, either by use of the Bu3SnH/AIBN system or by photostimulated electron transfer from a nucleophile, and the partition of the intermediate radical between competing pathways was investigated. Use both of indirect methods (such as the study of the reaction products in competition experiments; use of a radical-clock probe) and of direct ones (such as the detection of the radicals by flash photolysis experiments) enabled the following rate constants to be obtained (all values in m-l.s-1 at 25 °C). For phenyl type radicals, the rate constants for H abstraction (kH) from the solvents Me2SO (2.8.106) and CH3CN (6.7.106) and the rate constant for combination with a nucleophile (ky) such as Me3CCOCH2- ion (3.3.109) were determined. For vinyl radical Ph2C=C(.)Ph (7.), the kH values from Me2SO (1.1.105), CH3CN (1.2.105), Bu3SnH(7.5-108), and (Me3Si)3SiH (1.6.109) and the ky values with Me3CCOCH2- (3.9.107), (EtO)2PO(2.8.106), and PhS- (1.9.107) ions were determined. Semiempirical calculations confirmed a stabilization of radical 7.by the α-Ph substituent (ca. 8 kcal/mol), and provided the BDE of the C-Y bond for the vinylic substitution products of 7.. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002).
- Branchi, Barbara,Galli, Carlo,Gentili, Patrizia
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p. 2844 - 2854
(2007/10/03)
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- The reactivity of organothallium compounds. Kinetics and mechanism of iodination of diarylthallium salts by molecular iodine in dioxane
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The kinetics and mechanism of the reactions of diarylthallium trifluoroacetates with molecular iodine in dioxane solutions have been studied. The reaction has the overall second order with the first order with respect to each reagent. The effect of substi
- Gun'kin,Butin
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p. 448 - 452
(2007/10/03)
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- Synthetic use of poly[4-(diacetoxyiodo)styrene] for organic reactions
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Poly[4-(diacetoxyiodo)styrene] is sufficiently reactive for the iodination of aromatics, the oxidative 1,2-aryl migration of alkyl aryl ketones, the α-hydroxylation of ketones, and the oxidation of hydroquinones and sulfides similarly to (diacetoxyiodo)benzene. Here, those reactions with poly[4-(diacetoxyiodo)styrene] are very useful because of the simple operation; thus, filtration gives the crude products and recovered poly(4- iodostyrene), and then poly[4-(diacetoxyiodo)-styrene] can be regenerated by oxidation of the recovered poly(4-iodostyrene), which are reused for the same reactions.
- Togo, Hideo,Abe, Seiichiro,Nogami, Genki,Yokohama, Masataka
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p. 2351 - 2356
(2007/10/03)
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- Reactivity and synthetic utility of 1-(arenesulfonyloxy) benziodoxolones
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The reactivity and synthetic use of 1-(arenesulfonyloxy)benziodoxolones were studied. In the presence of iodine, 1-(arenesulfonyloxy)benziodoxolones iodinated various aromatics to give iodoarenes in moderate to good yields. In particular, 1-(p-chlorobenzenesulfonyloxy)benziodoxolone showed the best reactivity. Using a halide salt such as lithium bromide or lithium chloride instead of iodine, the corresponding aryl bromides and chlorides were also obtained in good yields. In the absence of aromatics, 1- (arenesulfonyloxy)benziodoxolones gave rise to desulfonyloxyiodination reactions to give the corresponding aryl iodides via electrophilic ipso substitution on the aromatic rings. Furthermore, the l-(p- toluenesulfonyloxy)benziodoxolone/iodine system iodotosyloxylated alkynes in good yields. These reactions proceeded via the formation of arenesulfonyl hypoiodites.
- Muraki, Takahito,Togo, Hideo,Yokoyama, Masataka
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p. 2883 - 2889
(2007/10/03)
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- The synthesis of [18F]fluoroarenes from the reaction of cyclotron-produced [18F]fluoride ion with diaryliodonium salts
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Diaryliodonium salts have been shown to react with fluoride ion at 80°C in acetonitrile to generate aryl fluorides. The regioselectivity is controlled electronically and by the bulk of the ortho-substituents on the rings, with the latter the dominant factor such that electron-rich rings can be fluorinated. ortho-Substituted aryl fluorides can be selectively produced from unsymmetrical diaryliodonium salts. The process has been used to synthesise [18F] labelled aromatics by the use of cyclotron generated [18F]fluoride ion.
- Shah, Aneela,Pike, Victor W.,Widdowson, David A.
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p. 2043 - 2046
(2007/10/03)
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- Synthetic application of poly[styrene(iodoso diacetate)]
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Poly[styrene(iodoso diacetate)] is sufficiently reactive to effect the iodination of aromatics and oxidative 1,2-aryl migration of alkyl aryl ketones as (diacetoxyiodo)benzene, and can be regenerated and reused for the same reactions.
- Togo, Hideo,Nogami, Genki,Yokoyama, Masataka
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p. 534 - 536
(2007/10/03)
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- Synthetic use of 1-(p-toluenesulfonyloxy)-1,2-benziodoxol-3(1H)-one: Iodination of aromatic rings
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Treatment of various aromatic compounds with 1-(p-toluenesulfonyloxy)-1,2-benziodoxol-3(1H)-one 1A and iodine gave the corresponding iodinated compounds in good yields. Similarly, chlorination and bromination proceeded effectively. As compared with other trivalent iodine compounds, the iodinane 1A showed the best reactivity as a halogenation reagent.
- Muraki, Takahito,Togo, Hideo,Yokoyama, Masataka
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p. 286 - 288
(2007/10/03)
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- Iodination of (E)-2,2,5,5-tetramethyl-3,4-diphenylhex-3-ene: Catalytic effects of silver triflate and water in the I2/Ag2SO4 iodination
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(E)-2,2,5,5-Tetramethyl-3 4-diphenylhex-3-ene does not iodinate under normal conditions. Silver trifluoromethanesulfonate catalysis of the silver sulfate/iodine promoted reaction is shown to add versatility to this reation and successfully produce (E)-3-(4'-iodophenyl)-2,2,5,5-tetramethyl-4-phenylhex-3-ene and (E)-2,2,5,5-tetramethyl-3,4-di(4'-iodophenyl)hex-3-ene in good yield under mild conditions. Success is shown to be dependent upon the presence of a trace of water in the dichloromethane solvent.
- Sekher, Padmanabhan,Gano, James E.,Luzik Jr., Eddie D.
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p. 3631 - 3636
(2007/10/03)
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- Initiation of Cationic Polymerization of Cyclic Ethers by Redox Radical-Chain Reactions of Onium Salts
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Redox radical-chain reactions of diaryliodonium halides (Ar2I(+)X(-)) with tetrahydrofuran (THF) and 1,3-dioxolane to give arenes (ArH) and iodoarenes (ArI) are reported.When the reactions are initiated by irradiation at 313 nm, the quantum yield for the formation of iodoarene is substantially greater than 1 (Φ ca. 2-20).Nonphotochemical radical initiators give the same reaction, showing that the photochemical step is simply an initiation step.The key propagation step in these reactions is a single-electron reduction of the onium salts by ether-derived radicals.The photoinitiated reaction with THF follows zero-order kinetics, showing that termination does not compete with electron transfer.In addition, the same nonphotochemical conditions that give radical-chain reduction of the diaryliodonium halides give rapid cationic polymerization of the ethers when the iodonium hexafluorophosphates are used.These observations establish the connection between the redox chemistry of the iodonium salt and the cationic polymerization of the eters.The polymerization of THF by iodonium salt in the presence of free radicals is accelerated by the addition of trimethyl phosphite (TMP).Furthermore, triarylsulfonium salts will initiate polymerization of THF in the presence of TMP and radical sources.Therefore, redox-chain reduction of these onium salts by TMP can also initiate cationic polymerization of the cyclic ethers.
- Kampmeier, J. A.,Nalli, Thomas W.
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p. 1381 - 1388
(2007/10/02)
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- Acid-Mediated Reaction of Bis(pyridine)iodonium(I) Tetrafluoroborate with Aromatic Compounds. A Selective and General Iodination Method
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Reaction of aromatic compounds with bis(pyridine)iodonium(I) tetrafluoroborate (IPy2BF4) in the presence of HBF4 or CF3SO3H in CH2Cl2 at room temperature furnishes monoiodo derivatives with excellent regioselectivity and yields.Use of either acid gives comparable results with activated aromatics, whereas CF3SO3H is much more effective in the iodination of deactivated aromatics.
- Barluenga, Jose,Gonzalez, Jose M.,Garcia-Martin, Miguel A.,Campos, Pedro J.,Asensio, Gregorio
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p. 2058 - 2060
(2007/10/02)
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- A Novel Aromatic Iodination Method Using F2
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A new method for direct aromatic iodination with IF, made in situ from the corresponding elements, is described.Depending on the reaction time and temperature, mono- or polyiodination can be achieved.Even deactivated aromatic rings can be directly iodinated without the presence of any Friedel-Crafts catalyst.Sensitive groups such as aromatic aldehydes are not affected by the reagent.
- Rozen, Shlomo,Zamir, Dov
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p. 3552 - 3555
(2007/10/02)
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- HALOGEN EXCHANGE REACTIONS OF ARYL HALIDES USING SUPPORTED COPPER(I)
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Halogen exchange reactions of unactivated and some activated aryl halides can be achieved using supported copper(I) in non-polar solvents.The complex supported reagent KI-CuI-alumina has been found to be especially effective for the normally unfavourable conversion of bromoaryls to iodoaryls.Negative ion FABMS has revealed the existence of CuX2(-) species on the support surface of most reagents but notably not on that of the complex KI-CuI-alumina reagent.
- Clark, James H.,Jones, Craig W.,Duke, Catherine V. A.,Miller, Jack M.
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p. 1745 - 1758
(2007/10/02)
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- Halogenation Using Quaternary Ammonium Polyhalides. XIV. Aromatic Bromination and Iodination of Arenes by Use of Benzyltrimethylammonium Polyhalides-Zinc Chloride System
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The reaction of arenes with benzyltrimethylammonium tribromide or benzyltrimethylammonium dichloroiodate in acetic acid in the presence of ZnCl2 at room temperature or at 70 deg C gave brome- or iodo-substituted arenes in good yield, respectively.
- Kajigaeshi, Shoji,Kakinami, Takaaki,Moriwaki, Masayuki,Tanaka, Toshio,Fujisaki, Shizuo,Okamoto, Tsuyoshi
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p. 439 - 443
(2007/10/02)
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- 4-tBUTYL IODOXYBENZENE : AN EFFECTIVE OZONE EQUIVALENT
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The specifically designed reagent, 4-tButyl iodoxybenzene (1) - soluble in hot, benzene, chlorobenzene and nitrobenzene - cleaves a range of ? bonds to carbonyl compounds in 50-75percent isolated yields.In every case, the reagent 1 is transformed to 4-tbutyl iodobenzene (2) in 90-97percent yields, which can be recycled.
- Ranganathan, S.,Ranganathan, D.,Singh, S. K.
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p. 4955 - 4956
(2007/10/02)
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- A Simple and General Route to Aryl Iodides from Arenes
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Mercury(II) oxide-tetrafluoroboric acid reacts with arenes under mild or very mild conditions to afford, after treatment with iodine in a 'one-stage' reaction, the corresponding aryl iodide.The orientation is that expected based on general aromatic substitution theory and hence the meta-iodinated derivatives of deactivated arenes are accessible.
- Barluenga, Jose,Campos, Pedro J.,Gonzalez, Jose M.,Asensio, Gregorio
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p. 2623 - 2624
(2007/10/02)
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- CATALYTIC CARBONYLATION OF DIARYLIODONIUM SALTS PROMOTED BY PALLADIUM-ZINC SYSTEM. A NEW SYNTHESIS OF DIARYL KETONES AND DIARYL-α-DIKETONES
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Diaryliodonium salts react with carbon monoxide, in the presence of zinc and a catalytic amount of palladium acetate, to give a mixture of the corresponding diaryl ketones and diaryl-α-diketones under mild conditions.
- Uchiyama, Masaharu,Suzuki, Takehiko,Yamazaki, Yasuo
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p. 1201 - 1202
(2007/10/02)
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