- Palladium-Catalyzed Decarbonylative Iodination of Aryl Carboxylic Acids Enabled by Ligand-Assisted Halide Exchange
-
We report an efficient and broadly applicable palladium-catalyzed iodination of inexpensive and abundant aryl and vinyl carboxylic acids via in situ activation to the acid chloride and formation of a phosphonium salt. The use of 1-iodobutane as iodide source in combination with a base and a deoxychlorinating reagent gives access to a wide range of aryl and vinyl iodides under Pd/Xantphos catalysis, including complex drug-like scaffolds. Stoichiometric experiments and kinetic analysis suggest a unique mechanism involving C?P reductive elimination to form the Xantphos phosphonium chloride, which subsequently initiates an unusual halogen exchange by outer sphere nucleophilic substitution.
- Boehm, Philip,Cacherat, Bastien,Lee, Yong Ho,Martini, Tristano,Morandi, Bill
-
supporting information
p. 17211 - 17217
(2021/07/02)
-
- Hydrogen-Bond-Donor Solvents Enable Catalyst-Free (Radio)-Halogenation and Deuteration of Organoborons
-
A hydrogen bond donor solvent assisted (radio)halogenation and deuteration of organoborons has been developed. The reactions exhibited high functional group tolerance and needed only an ambient atmosphere. Most importantly, compared to literature methods, our conditions are more consistent with the principals of green chemistry (e.g., metal-free, strong oxidant-free, more straightforward conditions).
- Yang, Yi,Gao, Xinyan,Zeng, Xiaojun,Han, Junbin,Xu, Bo
-
supporting information
p. 1297 - 1300
(2020/12/23)
-
- Orthogonal Stability and Reactivity of Aryl Germanes Enables Rapid and Selective (Multi)Halogenations
-
While halogenation is of key importance in synthesis and radioimaging, the currently available repertoire is largely designed to introduce a single halogen per molecule. This report makes the selective introduction of several different halogens accessible. Showcased here is the privileged stability of nontoxic aryl germanes under harsh fluorination conditions (that allow selective fluorination in their presence), while displaying superior reactivity and functional-group tolerance in electrophilic iodinations and brominations, outcompeting silanes or boronic esters under rapid and additive-free conditions. Mechanistic experiments and computational studies suggest a concerted electrophilic aromatic substitution as the underlying mechanism.
- Deckers, Kristina,Fricke, Christoph,Schoenebeck, Franziska
-
supporting information
p. 18717 - 18722
(2020/08/25)
-
- Generation of Organozinc Reagents by Nickel Diazadiene Complex Catalyzed Zinc Insertion into Aryl Sulfonates
-
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
-
supporting information
p. 176 - 180
(2019/12/11)
-
- Nickel-catalyzed cross-coupling reaction of carbamates with silylmagnesium reagents
-
The C–O bonds are kinetically inert in cross-coupling reactions compared to those of carbon–halogen bonds. Thus, developing methodologies for the activation of C–O bonds in cross-coupling reactions remains a major challenge. We disclose an unprecedented nickel mediated cross-coupling of carbamates with silylmagnesium reagents that does not require the expensive silylboranes. Silylmagnesium reagents were prepared from either silyllithium or silyl iodides. This methodology is distinguished by the synthesis of trimethylsilyl coupled product and its synthetic applications. Kinetic studies and radical clock experiments revealed the rate-limiting C–O bond cleavage, half order with respect to the catalyst and a non-radical transition state.
- Murugesan, Vetrivelan,Balakrishnan, Venkadesh,Rasappan, Ramesh
-
p. 293 - 298
(2019/08/12)
-
- Mechanism of Cu-catalyzed aryl boronic acid halodeboronation using electrophilic halogen: Development of a base-catalyzed iododeboronation for radiolabeling applications
-
An investigation into the mechanism of Cu-catalyzed aryl boronic acid halodeboronation using electrophilic halogen reagents is reported. Evidence is provided to show that this takes place via a boronate-driven ipso-substitution pathway and that Cu is not required for these processes to operate: General Lewis base catalysis is operational. This in turn allows the rational development of a general, simple, and effective base-catalyzed halodeboronation that is amenable to the preparation of 125I-labeled products for SPECT applications.
- Molloy, John J.,O'rourke, Kerry M.,Frias, Carolina P.,Sloan, Nikki L.,West, Matthew J.,Pimlott, Sally L.,Sutherland, Andrew,Watson, Allan J. B.
-
supporting information
p. 2488 - 2492
(2019/04/10)
-
- Regioselective Halogenation of Arenes and Heterocycles in Hexafluoroisopropanol
-
Regioselective halogenation of arenes and heterocycles with N-halosuccinimides in fluorinated alcohols is disclosed. Under mild condition reactions, a wide diversity of halogenated arenes are obtained in good yields with high regioselectivity. Additionally, the versatility of the method is demonstrated by the development of one-pot sequential halogenation and halogenation-Suzuki cross-coupling reactions.
- Tang, Ren-Jin,Milcent, Thierry,Crousse, Benoit
-
p. 930 - 938
(2018/01/28)
-
- Metathesis-active ligands enable a catalytic functional group metathesis between aroyl chlorides and aryl iodides
-
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
-
p. 1016 - 1022
(2018/09/06)
-
- 1,2-Silyl migration in 1-halonaphthalenes catalyzed by I2
-
1-Halo-8-hydrosilylnaphthalenes undergo 1,2-silyl migration to form 1-halo-7-silylnaphthalenes. The influence of the substituents on the silicon atom, the solvent effect, and the D-labeling experiments are investigated. The migration process may include four steps: (a) generation of acid (HI) by the reaction of the hydrosilane with I2, (b) protonation of the naphthalene ring, (c) silyl group migration in the protonated intermediate, and (d) deprotonation of the naphthalene ring.
- Shimizu, Tomomi,Morisako, Shogo,Yamamoto, Yohsuke,Kawachi, Atsushi
-
-
- An Unprecedented, Lewis Acid-Mediated, Metal-Free Iodoannulation Strategy to Aromatic Iodides
-
A direct transformation of ortho-alkynylated aromatic vinyl ethers to 1-iodonaphthalenes and other iodo-heterocycles under mild Lewis acidic conditions in the presence of iodide as an external nucleophile is reported. The first example of an iodoannulation strategy using a nucleophilic source of iodine, coupled with good to excellent yields, exclusive alpha regioselectivity and a broad substrate scope makes this work an attractive avenue towards the construction of aromatic iodides.
- Banik, Trisha,Betkekar, Vipul V.,Kaliappan, Krishna P.
-
p. 3676 - 3680
(2018/10/31)
-
- Transition-Metal-Free Decarboxylative Iodination: New Routes for Decarboxylative Oxidative Cross-Couplings
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Constructing products of high synthetic value from inexpensive and abundant starting materials is of great importance. Aryl iodides are essential building blocks for the synthesis of functional molecules, and efficient methods for their synthesis from chemical feedstocks are highly sought after. Here we report a low-cost decarboxylative iodination that occurs simply from readily available benzoic acids and I2. The reaction is scalable and the scope and robustness of the reaction is thoroughly examined. Mechanistic studies suggest that this reaction does not proceed via a radical mechanism, which is in contrast to classical Hunsdiecker-type decarboxylative halogenations. In addition, DFT studies allow comparisons to be made between our procedure and current transition-metal-catalyzed decarboxylations. The utility of this procedure is demonstrated in its application to oxidative cross-couplings of aromatics via decarboxylative/C-H or double decarboxylative activations that use I2 as the terminal oxidant. This strategy allows the preparation of biaryls previously inaccessible via decarboxylative methods and holds other advantages over existing decarboxylative oxidative couplings, as stoichiometric transition metals are avoided.
- Perry, Gregory J. P.,Quibell, Jacob M.,Panigrahi, Adyasha,Larrosa, Igor
-
supporting information
p. 11527 - 11536
(2017/08/30)
-
- Simple and Efficient Generation of Aryl Radicals from Aryl Triflates: Synthesis of Aryl Boronates and Aryl Iodides at Room Temperature
-
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
-
supporting information
p. 8621 - 8627
(2017/07/06)
-
- Copper-catalysed aromatic-Finkelstein reactions with amine-based ligand systems
-
A new efficient and low-cost ligand, diethylenetriamine, has been utilised to promote the iodination of 16 different bromo-substrates via the copper catalysed Finkelstein halogen exchange reaction under mild conditions. In contrast to earlier methods, the use of inert atmosphere conditions was not required to obtain high yields and purity. Studies on the speciation of the catalyst in solution indicate rapid disproportionation of copper(i) in the presence of diethylenetriamine to give copper(0) and a bis-ligated copper(ii) complex which is characterised by X-ray diffraction. This copper(ii) complex was also shown to be catalytically active in the halogen exchange reaction. In contrast, no significant disproportionation was observed using dimethylethylenediamine as the ligand, and the solid-state structures of a copper(i) dimeric complex and a 2D polymeric network of copper(i) iodide tetramers are reported. The catalytic activity of diethylenetriamine and dimethylethylenediamine with both copper(i) and copper(ii) salts are compared, and possible mechanistic implications discussed.
- Jin, Xiaodong,Davies, Robert P.
-
p. 2110 - 2117
(2017/07/22)
-
- Ligand-Controlled Regiodivergence in the Copper-Catalyzed [2,3]- and [1,2]-Rearrangements of Iodonium Ylides
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Despite the importance of allylic ylide rearrangements for the synthesis of complex molecules, the catalyst control of [2,3]- and [1,2]-rearrangements remains an unsolved problem. We developed the first regiodivergent [2,3]- and [1,2]-rearrangements of iodonium ylides that are controlled by copper catalysts bearing different ligands. In the presence of a 2,2′-dipyridyl ligand, diazoesters and allylic iodides react via a [2,3]-rearrangement pathway. Alternatively, a phosphine ligand favors the formation of the [1,2]-rearrangement product. A series of α-iodoesters containing a broad range of functional groups were obtained in high yields, regioselectivities, and diastereoselectivities. Deuterium-labeling studies suggest distinct mechanisms for the regioselective rearrangements.
- Xu, Bin,Tambar, Uttam K.
-
p. 12073 - 12076
(2016/09/28)
-
- By-Product-Catalyzed Redox-Neutral Sulfenylation/Deiodination/Aromatization of Cyclic Alkenyl Iodides with Sulfonyl Hydrazides
-
A by-product-catalyzed redox-neutral process has been established through tandem sulfenylation/deiodination/aromatization of cyclic alkenyl iodides with sulfonyl hydrazides. In the absence of external catalysts and additives a range of 4-iodo-1,2-dihydronaphthalenes reacted with sulfonyl hydrazides to give structurally diverse 2-naphthyl thioethers in good yields. Mechanistic studies showed that at an early stage sulfonyl hydrazides decomposed completely to thiosulfonates and disulfides and at a late stage the resulting thiosulfonates underwent tandem sulfenylation/deiodination/aromatization with 4-iodo-1,2-dihydronaphthalenes involving a [1,5]-sigmatropic hydrogen shift. Importantly, iodine was generated as a by-product from 4-iodo-1,2-dihydronaphthalenes upon heating and served as a catalyst for the decomposition of sulfonyl hydrazides and subsequent formation of 2-naphthyl thioethers. (Figure presented.).
- Yang, Fu-Lai,Gui, Yang,Yu, Bang-Kui,Jin, You-Xiang,Tian, Shi-Kai
-
supporting information
p. 3368 - 3372
(2016/11/13)
-
- Copper-catalyzed conversion of aryl and heteroaryl bromides into the corresponding iodide
-
An efficient method for the synthesis of aryl and heteroaryl iodides is described in this study. The reactions of aryl and heteroaryl bromides with potassium iodide proceeded smoothly in the presence of a copper catalyst under mild reaction conditions to produce the corresponding iodides in satisfactory to excellent yields.
- Feng, Xiujuan,Li, Lingyu,Yu, Xiaoqiang,Yamamoto, Yoshinori,Bao, Ming
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p. 129 - 132
(2016/07/06)
-
- Copper-mediated aerobic iodination and perfluoroalkylation of boronic acids with (CF3)2CFI at room temperature
-
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
-
-
- A robust microfluidic device for the synthesis and crystal growth of organometallic polymers with highly organized structures
-
A simple and robust microfluidic device was developed to synthesize organometallic polymers with highly organized structures. The device is compatible with organic solvents. Reactants are loaded into pairs of reservoirs connected by a 15 cm long microchannel prefilled with solvents, thus allowing long-term counter diffusion for self-assembly of organometallic polymers. The process can be monitored, and the resulting crystalline polymers are harvested without damage. The device was used to synthesize three insoluble silver acetylides as single crystals of X-ray diffraction quality. Importantly, for the first time, the single-crystal structure of silver phenylacetylide was determined. The reported approach may have wide applications, such as crystallization of membrane proteins, synthesis and crystal growth of organic, inorganic, and polymeric coordination compounds, whose single crystals cannot be obtained using traditional methods.
- Liu, Xiao,Yi, Qiaolian,Han, Yongzhen,Liang, Zhenning,Shen, Chaohua,Zhou, Zhengyang,Sun, Junliang,Li, Yizhi,Du, Wenbin,Cao, Rui
-
supporting information
p. 1846 - 1850
(2015/02/19)
-
- Photo-induced Metal-Catalyst-Free Aromatic Finkelstein Reaction
-
The facile iodination of aromatic compounds under mild conditions is a great challenge for both organic and medicinal chemistry. Particularly, the synthesis of functionalized aryl iodides by light has long been considered impossible due to their photo-lability, which actually makes aryl iodides popular starting materials in many photo-substitution reactions. Herein, a photo-induced halogen exchange in aryl or vinyl halides has been discovered for the first time. A broad scope of aryl iodides can be prepared in high yields at room temperature under exceptionally mild conditions without any metal or photo-redox catalysts. The presence of a catalytic amount of elemental iodine could promote the reaction significantly.
- Li, Lu,Liu, Wenbo,Zeng, Huiying,Mu, Xiaoyue,Cosa, Gonzalo,Mi, Zetian,Li, Chao-Jun
-
supporting information
p. 8328 - 8331
(2015/07/15)
-
- Metal-free iodination of arylboronic acids and the synthesis of biaryl derivatives
-
A simple, general and efficient method is developed for the metal-free iodination of arylboronic acids. The protocol uses very cheap molecular iodine as the halide source and potassium carbonate as the base. The method is highly tolerant of various functional groups present in the substrates. Importantly, the iodination strategy can also be applied very effectively in the one-pot, two-step synthesis of biaryl derivatives. Georg Thieme Verlag Stuttgart New York.
- Niu, Liting,Zhang, Hao,Yang, Haijun,Fu, Hua
-
supporting information
p. 995 - 1000
(2014/05/06)
-
- A palladium-catalyzed domino reaction as key step for the synthesis of functionalized aromatic amino acids
-
A variety of substituted aromatic systems are synthesized by the Catellani reaction. These are used as precursors for novel amino acids with a basic side chain. Georg Thieme Verlag Stuttgart New York.
- Stark, Tina,Suhartono, Marcel,G?bel, Michael W.,Lautens, Mark
-
supporting information
p. 2730 - 2734
(2014/01/06)
-
- A simple and effective copper catalyst for the conversion of arylboronic acids to aryl iodides at room temperature
-
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
-
-
- Halodeboronation of organotrifluoroborates using tetrabutylammonium tribromide or cesium triiodide
-
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
-
experimental part
p. 3738 - 3743
(2012/06/30)
-
- Facile aromatic finkelstein iodination (AFI) reaction in 1,3-dimethyl-2-imidazolidinone (DMI)
-
In this communication, we report the superior role of 1,3-dimethyl-2- imidazolidinone (DMI) as a solvent for aromatic Finkelstein iodination (AFI), the conversion of aryl bromides to aryl iodides. DMI accelerates the reaction rate and affords product(s) that could not be prepared using previous methods. Our findings for AFI avoid the use of toxic solvents such as N,N-dimethylformamide and hexamethylphosphoramide. Taylor & Francis Group, LLC.
- Yamashita, Ken-Ichi,Tsuboi, Michihiro,Asano, Motoko S.,Sugiura, Ken-Ichi
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experimental part
p. 170 - 175
(2011/11/29)
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- PROCESS FOR THE PREPARATION OF IODIDES
-
This invention is directed to a process for the preparation of high yield alkyl or aryl iodide from its corresponding carboxylic acid using N-iodo amides.
- -
-
Page/Page column 34
(2012/01/05)
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- Pseudo five-component synthesis of 2,5-di(hetero)arylthiophenes via a one-pot Sonogashira-Glaser cyclization sequence
-
Based upon a consecutive one-pot Sonogashira-Glaser coupling-cyclization sequence a variety of 2,5-di(hetero)arylthiophenes were synthesized in moderate to good yields. A single Pd/Cu-catalyst system, without further catalyst addition, and easily available, stable starting materials were used, resulting in a concise and highly efficient route for the synthesis of the title compounds. This novel pseudo five-component synthesis starting from iodo(hetero)arenes is particularly suitable as a direct access to well-defined thiophene oligomers, which are of peculiar interest in materials science.
- Urselmann, Dominik,Antovic, Dragutin,Mueller, Thomas J. J.
-
supporting information; experimental part
p. 1499 - 1503
(2011/12/22)
-
- Copper-catalyzed halogenation of arylboronic acids
-
In this Letter, a copper-catalyzed halogenation of arylboronic acids was described. This reaction tolerates a variety of functional groups, providing aromatic halides with good yields. It represents a facile and mild procedure to aryl halides.
- Zhang, Guangyou,Lv, Guanglei,Li, Liping,Chen, Fan,Cheng, Jiang
-
experimental part
p. 1993 - 1995
(2011/04/25)
-
- General copper-catalyzed transformations of functional groups from arylboronic acids in water
-
A simple and general copper-catalyzed method has been developed for transformations of various functional groups (i I, i N3, i SO2R, i OH, i NH2, and i NO 2) on aromatic rings from arylboronic acids in water under air. The protocol uses cheap and readily available inorganic salts (KI, NaN3, NaSO2R, NaOH, NaNO2) and aqueous ammonia as the functional-group sources, simple Cu2O/NH3 as the catalyst system, environmentally friendly water as the solvent, and oxygen in air as the oxidant. Importantly, the copper catalyst system in water was recyclable. This study should provide a useful strategy for interconversions of the functional groups on aromatic rings.
- Yang, Haijun,Li, Yong,Jiang, Min,Wang, Junmei,Fu, Hua
-
experimental part
p. 5652 - 5660
(2011/06/23)
-
- 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.
- -
-
Page/Page column 10
(2010/05/13)
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- Desulfonyloxyiodination of arenesulfonic acids with mCPBA and molecular iodine
-
Treatment of p-alkylbenzenesulfonic acids with mCPBA and molecular iodine gave p-alkyliodobenzenes in good to moderate yields via electrophilic ipso-substitution by the iodonium species (I+) formed. This desulfonyloxyiodination was promoted by the addition of a catalytic amount of iodoarenes, such as o-iodobenzoic acid. The same treatment of dimethylbenzenesulfonic acids and trimethylbenzenesulfonic acids with mCPBA and molecular iodine proceeded smoothly both in the absence and in the presence of o-iodobenzoic acid to provide the corresponding monoiodo-dimethylbenzene and diiodo-dimethylbenzene, and diiodo-trimethylbenzene and triiodo- trimethylbenzene, in good to moderate yields, respectively. On the other hand, the same desulfonyloxyiodination of benzenesulfonic acid and p-chlorobenzenesulfonic acid with mCPBA and molecular iodine proceeded only in the presence of o-iodobenzoic acid to generate iodobenzene and p-chloroiodobenzene, respectively, in moderate yields.
- Suzuki, Yuhsuke,Ishiwata, Yoshihide,Moriyama, Katsuhiko,Togo, Hideo
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experimental part
p. 5950 - 5953
(2010/11/21)
-
- A convenient procedure for the iodination of arenes
-
Two different procedures for the iodination of various arenes using potassium bromate and potassium iodide in the presence of hydrochloric acid are presented. Iodination of benzene, naphthalene and deactivated arenes were carried out in aqueous acetic acid medium and good yields of iodoarenes were obtained. Activated arenes, such as anisole, substituted phenols and anilines underwent excellent conversion to their iodinated products in an aqueous methanol medium.
- Sathiyapriya,Karunakaran, R. Joel
-
p. 575 - 576
(2007/10/03)
-
- Pronounced catalytic effect of micellar solution of sodium dodecyl sulfate (SDS) for regioselective iodination of aromatic compounds with a sodium iodide/cerium(IV) trihydroxide hydroperoxide system
-
Micellar solutions of sodium dodecyl sulfate (SDS) catalyze the regioselective iodination of a wide range of aromatic compounds with sodium iodide in the presence of the easily prepared, water-resistant and recyclable cerium(IV) trihydroxide hydroperoxide, Ce(OH)3O2H, at room temperature. By this protocol, structurally diverse aromatic compounds including benzene and naphthalene were iodinated in good to excellent yields.
- Firouzabadi, Habib,Iranpoor, Nasser,Garzan, Atefeh
-
p. 1925 - 1928
(2007/10/03)
-
- Comparative study of the reactivity of iodinating agents in solution and solid phase
-
The results of reactions of a series of aromatic substrates with iodine, iodine(I) chloride, and N-iodosuccinimide in solution and solid phase were compared for the first time. In all cases, the general relations holding in the iodination process were similar. Iodine(I) chloride was found to chlorinate anthracene. A high efficiency of solid-phase iodination of β-diketones was demonstrated using dibenzoylmethane as an example.
- Krasnokutskaya,Lesina,Gorlushko,Filimonov
-
p. 855 - 859
(2007/10/03)
-
- Regioselective haloaromatization of 1,2-bis(ethynyl)benzene via halogen acids and PtCl2. Platinum-catalyzed 6-π electrocyclization of 1,2-bis(1′-haloethenyl)benzene intermediates
-
Treatment of 1,2-bis(ethynyl)benzene (1) with aqueous HX (X = Br, I) in hot 3-pentanone (100-105 °C, 2 h) afforded 1,2-bis(1′-haloethenyl)benzene species 2-Br and 2-I in 98% and 95% yields, respectively. The hydrochlorination of endiyne 1 failed to proceed at elevated temperature but was implemented efficiently by PtCl2 (5 mol %) in hot 3-pentanone (100 °C, 2 h) to give 1,2-bis(1′-chloroetheny)benzene 2-Cl in 80% yield. In the presence of PtCl2 (5 mol %), these halides 2-Cl, 2-Br, and 2-I were subsequently converted to 1-halonaphthalenes 3-Cl, 3-Br, and 3-I in the mother solution via sequential 6-π electrocyclization and dehalogenation reactions. PtCl2 (5 mol %) also effected direct haloaromatization of endiyne 1 with HX (X = Cl, Br, I) and gave 1-halonaphthalenes 3-Cl, 3-Br, and 3-I in 64-71% yields. This investigation reports the scope and the regioselectivity of haloaromatization of various enediynes catalyzed by PtCl2.
- Lo, Ching-Yu,Kumar, Manyam Praveen,Chang, Hsu-Kai,Lush, Shie-Fu,Liu, Rai-Shung
-
p. 10482 - 10487
(2007/10/03)
-
- Efficient one-pot transformation of aminoarenes to haloarenes using halodimethylisulfonium halides generated in situ
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Halodimethylsulfonium halide 1, which is readily formed in situ from hydrohaloic acid and DMSO, is a good nucleophilic halide. This activated nucleophilic halide rapidly converts aryldiazonium salt prepared in situ by the same hydrohaloic acid and nitrite ion to aryl chlorides, bromides, or iodides in good yield. The combined action of nitrite ion and hydrohaloic acid in DMSO is required for the direct transformation of aromatic amines, which results in the production of aryl halides within 1 h. Substituted compounds with electron-donating or -withdrawing groups or sterically hindered aromatic amines are also smoothly transformed to the corresponding aromatic halides. The only observed by-product is the deaminated arene (usually 7%). The isolated aryldiazonium salts can also be converted to the corresponding aryl halides using 1. The present method offers a facile, one-step procedure for transforming aminoarenes to haloarenes and lacks the environmental pollutants that usually accompany the Sandmeyer reaction using copper halides.
- Baik, Woonphil,Luan, Wanqiang,Lee, Hyun Joo,Yoon, Cheol Hun,Koo, Sangho,Kim, Byeong Hyo
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p. 213 - 219
(2007/10/03)
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- Acid-catalysed selective monoiodination of electron-rich arenes by alkali metal iodides
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The reaction of electron-rich arenes with alkali metal iodides such as sodium and potassium iodides in the presence of cone. H2SO 4 gives p-iodoarenes in high yields.
- Pasha,Myint, Yi Yi
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p. 2829 - 2833
(2007/10/03)
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- A facile synthesis of aryl iodides via potassium aryltrifluoroborates
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Aryl- and heteroaryltrifluoroborates are rapidly converted to aryl and heteroaryl iodides under mild conditions using sodium iodide in the presence of mild oxidizing agents.
- Kabalka, George W.,Mereddy, Arjun R.
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p. 343 - 345
(2007/10/03)
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- An Efficient, Catalytic, Aerobic, Oxidative Iodination of Arenes Using the H5PV2Mo10O40 Polyoxometalate as Catalyst
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Iodination of arenes was carried out by reacting 1 equiv of arene substrate with 0.5 equiv of iodine under an oxygen atmosphere with H 5PV2Mo10O40 as oxidation catalyst. The synthesis is an inherently waste-free method for the preparation of iodoarenes.
- Branytska, Olena V.,Neumann, Ronny
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p. 9510 - 9512
(2007/10/03)
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- Direct and regioselective iodination and bromination of benzene, naphthalene and other activated aromatic compounds using iodine and bromine
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Direct and regioselective iodination and bromination of benzene, naphthalene and other activated aromatic compounds with iodine and bromine or their sodium salts proceed well in the presence of Fe(NO3) 3·1.5N2O4/charcoal in CH 2Cl2 at room temperature.
- Firouzabadi,Iranpoor,Shiri
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p. 8781 - 8785
(2007/10/03)
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- Process for producing iodinated aromatic compounds
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Disclosed is a process for producing an iodinated aromatic compound, which comprises reacting an aromatic compound with an iodine compound in the presence of a chlorate as an oxidizing agent.
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- Antiinflammation agents
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Compounds, compositions and methods that are useful in the treatment of inflammatory, immunoregulatory, metabolic and cell proliferative conditions or diseases are provided herein. In particular, the invention provides compounds which modulate the expression and/or function of proteins involved in inflammation, metabolism and cell proliferation. The subject compounds contain fused carbocyclic or heterocyclic rings.
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- 2,4,6,8-tetraiodo-2,4,6,8-tetraazabicyclo[3.3.0]octane-3,7-dione as a mild and convenient reagent for iodination of aromatic compounds
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2,4,6,8-Tetraiodo-2,4,6,8-tetraazabicyclo[3.3.0]octane-3,7-dione (tetraiodoglycoluril) is a convenient reagent for preparative iodination of benzene, alkylbenzenes, polycyclic hydrocarbons, aromatic amines, and phenol ethers in organic solvents under mild conditions.
- Chaikovski,Filimonov,Yagovkin,Ogorodnikov
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p. 2411 - 2415
(2007/10/03)
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- Aromatic iodination: A new investigation on the nature of the mechanism
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Following a suggestion by the late Lennart Eberson, we have employed the ICl-HFP (HFP being hexafluoropropan-2-ol) system in iodination reactions, and found unambiguous evidence for the occurrence of an ET-mechanism of halogenation. The evidence is based on the use of 'intelligent' substrates, which make it possible to fix the boundaries between the occurrence of an ET-mechanism and of a conventional polar mechanism. In an 'intelligent' substrate, in fact, the nature of the product(s) changes significantly depending on the operating mechanism. The ICl-HFP combination is instrumental to the onset of a one-electron oxidation with electron-rich substrates, followed by halogenation. The most prominent example is that of the electron-rich substrate durene (1,2,4,5-tetramethylbenzene, DUR), when compared to mesitylene (1,3,5-trimethylbenzene, MES): with a 'conventional' iodination system (i.e., I2/ Ag+) and in common solvents, where the polar mechanism holds, durene is less reactive (kMES/kDUR = 46 ± 3), but becomes more reactive (kMES/kDUR = 0.23) in HFP with ICl, where the ET-mechanism takes over. Other substrates also support the onset of ET-pathways in HFP. Finally, a preliminary survey of a biohalogenation reaction induced by laccase indicates the modest occurrence of a polar process of iodination with a few substrates.
- Fabbrini, Maura,Galli, Carlo,Gentili, Patrizia,Macchitella, Daniele,Petride, Horia
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p. 1516 - 1521
(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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- Halodediazoniations of dry arenediazonium o-benzenedisulfonimides in the presence or absence of an electron transfer catalyst. Easy general procedures to prepare aryl chlorides, bromides, and iodides
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The paper reports the results of a wide study aimed at preparing aryl chlorides 3 (19 examples), bromides 4 (19 examples), and iodides 5 (9 examples) by halodediazoniation of dry arenediazonium o-benzenedisulfonimides 1 with tetraalkylammonium halides 2. The reactions were carried out in anhydrous acetonitrile at room temperature (~20 °C) in the presence of copper powder and at 60 °C or room temperature without the catalyst. In optimal conditions the yields were from good to excellent (60 reactions, 61- 94% yield), with only a few exceptions (8 reactions, 51-55% yield). A good amount of the o-benzenedisulfonimide (7) was always recovered from the reactions and could then be reused to prepare salts 1. An interesting aspect of this research is the surprising role of the anion of o- benzenedisulfonimide (9) as an electron transfer agent.
- Barbero,Degani,Dughera,Fochi
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p. 3448 - 3453
(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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- 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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- Palladium-Catalyzed Methylation of Aryl and Vinyl Halides by Stabilized Methylaluminum and Methylgallium Complexes
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The intramolecularly stabilized mono- and dialkylaluminum complexes 1a, 2, 3, 4a, 5a, 5c, 6a, 6c, 7, 8, and 9 in the presence of palladium catalysts, cross-alkylate aryl, vinyl, and benzyl bromides and iodides under mild standard laboratory conditions. Aryl bromides with carbonyl substituents or benzylic halides are converted partially into dialkyl compounds. Under similar conditions, the analogous stabilized dimethylgallium complexes 1b, 4b, 5b, 6b, and 10 methylate aryl and vinyl bromides and iodides in a highly selective manner. Substituted bromobenzenes XC6H4Br, where X = CHO, COPh, CO2Et, CN, NO2, Cl, CH2Br, or CH=CHCOPh, are methylated by the organogallium reagents usually only at the aromatic ring halogen atom to give substituted toluenes as single products. The methylation rates were shown to depend on the nature of the chelating ligands, on the solvent, and on the type of palladium catalyst employed.
- Blum, Jochanan,Gelman, Dmitri,Baidossi, Wael,Shakh, Eduard,Rosenfeld, Ayelet,Aizenshtat, Zeev,Wassermann, Birgit C.,Frick, Michael,Heymer, Bernd,Schutte, Stefan,Wernik, Sonja,Schumann, Herbert
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p. 8681 - 8686
(2007/10/03)
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- The Oxyiodination of Aromatic Compounds over Zeolite KX: The Case of Naphthalene
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Aromatic compounds, iodine, and oxygen react in the vapor phase over basic faujasite zeolites at 225-350 deg C to produce iodoaromatic compounds and water.When the aromatic compond is naphthalene and the reaction is conducted in the region of 250 deg C over KX zeolite, a shape-selective catalytic oxyiodination occurs, resulting in predominant iodination at the 2-position of naphthalene.Typical product mixtures contain approximately 10percent 1-iodonaphthalene, 65percent 2-iodonaphthalene, 19percent 2,6-diiodonaphthalene, 5percent other diiodonaphthalene isomers, and 1percent mixed triiodonaphthalene isomers at approximately 20percent naphthalene conversion and 80-99percent iodine conversion.Excessive conversion and excessive residence time reduce the selectivity to kinetic product, 2,6-diiodonaphthalene, but do not alter the selectivity for iodination in the 2-position.Selectivity for iodination in the 2-position is decreased by substituting sodium for potassium in the zeolite, by alterning the faujasite zeolite Si/Al ratio significantly above or below 1.25 and by increasing the amount of iodine in the reactant feed.
- Tustin, Gerald C.,Rule, Mark
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p. 186 - 198
(2007/10/02)
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- Cyclic 1,8-napththalenediyl compounds containing group 14 hetero atoms
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Reaction of 1,8-naphthalenediylmagnesium with dimethylgermanium dichloride gave only dimethyl(1,8-naphthalenediyl) germanium (7), whereas use of 1,8-dilithionaphthalene gave a mixture of products, consisting mainly of 7 and its "dimer" 7,7,14,14-tetramethyldinaphtho digermocin (8).The silicon analogue (12) of 8 was prepared in a two-step procedure, starting from 1,8-dilithionaphthalene and 1,1,2,2-tetrachloro-1,2-dimethyl-disilane.The molecular structures of 8 and 12 were determined by single crystal X-ray diffraction studies.Both structures are centrosymmetric.The central eight-membered rings containing the (CH3)2E moieties (E=Si, Ge) have a chair-like conformation.The naphthalene rings are quasi-coplanar and show strong out-of-plane distortions which are larger for 12 than for 8.Keywords: Naphthalenediyl; Lithium; Silicum; Germanium; Crystal structure
- Tinga, Markus A. G. M.,Buisman, Godfried J. H.,Schat, Gerrit,Akkerman, Otto S.,Bickelhaupt, Friedrich,et al.
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p. 137 - 146
(2007/10/02)
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