- Sulfated polyborate-H2O assisted tunable activation of N-iodosuccinimide for expeditious mono and diiodination of arenes
-
Owing to both Lewis and Bronsted acid active sites on sulfated polyborate under homogenous conditions, we were keen on developing iodination protocol of arenes that can meet the requirement of regioselectivity and higher yield. The sulfated polyborate activates N-iodosuccinimide for mono iodination of highly activated substrates viz. phenols, anilines under anhydrous condition. Water tunes sulfated polyborate to generate more Bronsted acid sites resulting in rapid activation of NIS for diiodination. The protocol was equally applicable to diiodination of 4-hydroxyphenylacetic acid to synthesize 4-hydroxy-3,5-diiodophenylacetic acid, an intermediate of tiratricol, a thyroid treatment drug. This protocol was further integrated via one-pot sequential iodination and Sonogashira coupling to synthesize aryl acetylenes, building blocks for the synthesis of a variety of specialty chemicals, API, and natural products.
- Misal, Balu,Palav, Amey,Ganwir, Prerna,Chaturbhuj, Ganesh
-
supporting information
(2021/05/26)
-
- NCBSI/KI: A Reagent System for Iodination of Aromatics through in Situ Generation of I-Cl
-
In situ iodine monochloride (I-Cl) generation followed by iodination of aromatics using NCBSI/KI system has been developed. The NCBSI reagent requires no activation due to longer bond length, lower bond dissociation energy, and higher absolute charge density on nitrogen. The system is adequate for mono- and diiodination of a wide range of moderate to highly activated arenes with good yield and purity. Moreover, the precursor N-(benzenesulfonyl)benzenesulfonamide can be recovered and transformed to NCBSI, making the protocol eco-friendly and cost-effective.
- Palav, Amey,Misal, Balu,Chaturbhuj, Ganesh
-
p. 12467 - 12474
(2021/08/24)
-
- R4NHal/NOHSO4: A Usable System for Halogenation of Isoxazoles, Pyrazoles, and beyond
-
A new convenient and versatile halogenating system (R4NHal/NOHSO4), giving straightforward and general access to halogenated 3,5-diaryl- and alkylarylisoxazoles, pyrazoles and electron-rich benzenes from the corresponding scaffolds, is suggested. The method provides excellent regioselectivity, scalability to the gram scale, and a broad scope for both aromatics and halogens. A three-step, one-pot reaction protocol was developed, and a series of 3,5-diaryl-4-haloisoxazoles has been efficiently synthesized from 1,2-diarylcyclopropanes under suggested nitrosating-halogenating conditions.
- Bondarenko, Oksana B.,Karetnikov, Georgy L.,Komarov, Arseniy I.,Pavlov, Aleksandr I.,Nikolaeva, Svetlana N.
-
supporting information
p. 322 - 332
(2021/01/14)
-
- Pseudocyclic bis-N-heterocycle-stabilized iodanes - synthesis, characterization and applications
-
Bis-N-heterocycle-stabilized λ3-iodanes (BNHIs) based on azoles are introduced as novel structural motifs in hypervalent iodine chemistry. A performance test in a variety of benchmark reactions including sulfoxidations and phenol dearomatizations revealed a bis-N-bound pyrazole substituted BNHI as the most reactive derivative. Its solid-state structure was characterizedviaX-ray analysis implying strong intramolecular interactions between the pyrazole nitrogen atoms and the hypervalent iodine centre.
- Boelke, Andreas,Lork, Enno,Nachtsheim, Boris J.,Sadat, Soleicha
-
supporting information
p. 7434 - 7437
(2021/08/03)
-
- 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)
-
- Shelf-Stable (E)- A nd (Z)-Vinyl-λ3-chlorane: A Stereospecific Hyper-vinylating Agent
-
We report the first stereoselective synthesis of stable (E)- A nd (Z)-β-chlorovinyl-λ3-chlorane via direct mesitylation of 1,2-dichloroethylene with mesityldiazonium tetrakis(pentafluorophenyl)borate under mild reaction conditions. The structure of the (E)-vinyl-λ3-chlorane was established by single-crystal X-ray analysis. Because of the enormously high leaving group ability of the aryl-λ3-chloranyl group, vinyl-λ3-chloranes undergo not only SNVσ-type reaction with extremely weak nucleophiles such as perfluoroalkanesulfonate, iodobenzene, and aromatic hydrocarbons but also coupling with phenylcopper(I) species.
- Kanazawa, Junichiro,Miyamoto, Kazunori,Takagi, Taisei,Uchiyama, Masanobu,Watanabe, Yuichiro
-
supporting information
p. 3469 - 3473
(2020/04/30)
-
- Selective Vicinal Diiodination of Polycyclic Aromatic Hydrocarbons
-
Vicinally diiodinated polycyclic aromatic hydrocarbons (I2-PAHs) are accessible from the corresponding diborylated B2-PAHs through boron/iodine exchange. The B2-PAHs have been prepared via twofold electrophilic borylation reactions templated by a vicinally disilylated benzene. Our protocol is applicable to fluorenes, acenes, annulated acenes, oligoaryls, and even [5]helicene. Using B2-naphthalene as the example, we have shown that the reaction scope can, in principle, be expanded to include the synthesis of vicinally dibrominated and dihydroxylated PAHs. The usefulness of the building blocks provided by our method in the field of optoelectronic materials was demonstrated by the successful conversion of I2-fluoranthene to the analogous doubly alkynylated fluoranthene emitter.
- Bolte, Michael,Jin, Tao,John, Alexandra,Kaehler, Tanja,Lerner, Hans-Wolfram,Wagner, Matthias
-
supporting information
p. 5847 - 5851
(2020/09/09)
-
- Photocatalytic Oxidative Iodination of Electron-Rich Arenes
-
A visible-light-mediated oxidative iodination of electron-rich arenes has been developed. 2.5 mol% of unsubstituted anthraquinone as photocatalyst were used in combination with elementary iodine, trifluoroacetic acid and oxygen as the terminal oxidant. The iodination proceeds upon irradiation in non- or weakly-electron donating solvents (DCM, DCE and benzene) wherein a spectral window in strongly coloured iodine solutions can be observed at around 400 nm. The method provides good to excellent yields (up to 98%) and shows excellent regioselectivity and good functional group tolerance (triple bonds, ketone, ester, amide). Moreover, the photo-iodination was also upscaled to a 5 mmol scale (1.1 g). Mechanistic investigations by intermediate trapping and competition experiments indicate a photocatalytic arene oxidation and the subsequent reaction with iodine as a likely mechanistic pathway. (Figure presented.).
- Narobe, Rok,Düsel, Simon J. S.,Iskra, Jernej,K?nig, Burkhard
-
supporting information
p. 3998 - 4004
(2019/07/17)
-
- Disulfide-Catalyzed Iodination of Electron-Rich Aromatic Compounds
-
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
-
-
- Disulfide-Catalyzed Iodination of Electron-Rich Aromatic Compounds
-
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
-
p. 7411 - 7417
(2019/06/18)
-
- Decarboxylative Suzuki-Miyaura coupling of (hetero)aromatic carboxylic acids using iodine as the terminal oxidant
-
A novel methodology for the decarboxylative Suzuki-Miyaura-type coupling has been established. This process uses iodine or a bromine source as both the decarboxylation mediator and the terminal oxidant, thus avoiding the need for stoichiometric amounts of transition metal salts previously required. Our new protocol allows for the construction of valuable biaryl architectures through the coupling of (hetero)aromatic carboxylic acids with arylboronic acids. The scope of this decarboxylative Suzuki reaction has been greatly diversified, allowing for previously inaccessible non-ortho-substituted aromatic acids to undergo this transformation. The procedure also benefits from low catalyst loadings and the absence of stoichiometric transition metal additives.
- Quibell, Jacob M.,Duan, Guojian,Perry, Gregory J.P.,Larrosa, Igor
-
supporting information
p. 6445 - 6448
(2019/06/07)
-
- Metal-Free, Oxidant-Free, and Controllable Graphene Oxide Catalyzed Direct Iodination of Arenes and Ketones
-
A direct, metal-free, and oxidant-free method for the graphene oxide (GO)-catalyzed iodination of arenes and ketones with iodine in a neutral medium was explored. This iodination protocol was performed by using a simple technique to avoid the use of external metal catalysts and oxidants and harsh acidic/basic reaction conditions. In addition, by this method the degree of iodination could be controlled, and the reaction was scalable and compatible with air. This strategy opens a new field for GO-catalyzed chemistry and provides an avenue for the convenient direct iodination of arenes and ketones.
- Zhang, Jingyu,Li, Shiguang,Deng, Guo-Jun,Gong, Hang
-
p. 376 - 380
(2017/12/07)
-
- 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)
-
- Functional Group Transposition: A Palladium-Catalyzed Metathesis of Ar-X σ-Bonds and Acid Chloride Synthesis
-
We describe the development of a new method to use palladium catalysis to form functionalized aromatics: via the metathesis of covalent σ-bonds between Ar-X fragments. This transformation demonstrates the dynamic nature of palladium-based oxidative addition/reductive elimination and offers a straightforward approach to incorporate reactive functional groups into aryl halides through exchange reactions. The reaction has been exploited to assemble acid chlorides without the use of high energy halogenating or toxic reagents and, instead, via the metathesis of aryl iodides with other acid chlorides.
- De La Higuera Macias, Maximiliano,Arndtsen, Bruce A.
-
supporting information
p. 10140 - 10144
(2018/08/23)
-
- Direct Transformation of Arylamines to Aryl Halides via Sodium Nitrite and N-Halosuccinimide
-
A one-pot universal approach for transforming arylamines to aryl halides via reaction with sodium nitrite (NaNO2) and N-halosuccinimide (NXS) in DMF at room temperature under metal- and acid-free condition is described. This new protocol that is complementary to the Sandmeyer reaction, is suggested to involve the in situ generation of nitryl halide induce nitrosylation of aryl amine to form the diazo intermediate which is halogenated to furnish the aryl halide.
- Mukhopadhyay, Sushobhan,Batra, Sanjay
-
supporting information
p. 14622 - 14626
(2018/09/21)
-
- Rapid aerobic iodination of arenes mediated by hypervalent iodine in fluorinated solvents
-
Arenes are rapidly converted to the corresponding iodides by aerobic oxidative iodination at room temperature by treatment with iodine and catalytic quantities of nitrous acid in a fluorinated solvent. Dichloroiodic acid is proposed as the actual iodination reagent.
- Iskra, Jernej,Murphree, S. Shaun
-
supporting information
p. 645 - 648
(2017/01/28)
-
- Transition-Metal-Free Decarboxylative Iodination: New Routes for Decarboxylative Oxidative Cross-Couplings
-
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)
-
- Aliphatic C-H Bond Iodination by a N-Iodoamide and Isolation of an Elusive N-Amidyl Radical
-
Contrary to C-H chlorination and bromination, the direct iodination of alkanes represents a great challenge. We reveal a new N-iodoamide that is capable of a direct and efficient C-H bond iodination of various cyclic and acyclic alkanes providing iodoalkanes in good yields. This is the first use of N-iodoamide for C-H bond iodination. The method also works well for benzylic C-H bonds, thereby constituting the missing version of the Wohl-Ziegler iodination reaction. Mechanistic details were elucidated by DFT computations, and the N-centered radical derived from the used N-iodoamide, which is the key intermediate in this process, was matrix-isolated in a solid argon matrix and characterized by UV-vis as well as IR spectroscopy.
- Artaryan, Alexander,Mardyukov, Artur,Kulbitski, Kseniya,Avigdori, Idan,Nisnevich, Gennady A.,Schreiner, Peter R.,Gandelman, Mark
-
p. 7093 - 7100
(2017/07/26)
-
- Late stage iodination of biologically active agents using a one-pot process from aryl amines
-
A simple and effective one-pot tandem procedure that generates aryl iodides from readily available aryl amines via stable diazonium salts has been developed. The operationally simple procedure and mild conditions allow late-stage iodination of a wide range of aryl compounds bearing various functional groups and substitution patterns. A novel synthetic strategy involving the preparation of nitroaryl compounds followed by a chemoselective tin(ii) dichloride reduction and the use of the one-pot diazotisation-iodination transformation was also developed. The general applicability of this approach was demonstrated with the preparation of a number of medicinally important compounds including CNS1261, a SPECT imaging agent of the N-methyl-d-aspartate (NMDA) receptor and IBOX, a compound used to detect amyloid plaques in the brain.
- Sloan, Nikki L.,Luthra, Sajinder K.,McRobbie, Graeme,Pimlott, Sally L.,Sutherland, Andrew
-
p. 54881 - 54891
(2017/12/12)
-
- Ligand- and Base-Free Access to Diverse Biaryls by the Reductive Coupling of Diaryliodonium Salts
-
A ligand- and base-free, Pd-catalyzed protocol to access a wide range of symmetrical and unsymmetrical biaryls from stable diaryliodonium salts was developed. The reaction involved the use of an effective and recyclable Pd/polyethylene glycol-400 catalyst system to harness the aryl moieties of two diaryliodonium salts; the ensuing biaryls may be utilized to synthesize an array of useful compounds, including 5-aryluracils, carbazoles, chromenones, fluorenones, phenathridines, and boscalid analogues.
- Arun,Reddy, P. O. Venkataramana,Pilania, Meenakshi,Kumar, Dalip
-
supporting information
p. 2096 - 2100
(2016/05/09)
-
- Para-Selective Cu-Catalyzed C-H Aryloxylation of Electron-Rich Arenes and Heteroarenes
-
Cu-catalyzed reaction of phenols with electron-rich arene or heteroarene ligands of unsymmetrical diaryl-λ3-iodanes is a key step in the developed one-pot two-step method for intermolecular para-selective C-H aryloxylation of heteroarenes and arenes.
- Sokolovs, Igors,Suna, Edgars
-
p. 371 - 379
(2016/01/25)
-
- Para-Selective C-H Amidation of Simple Arenes with Nitriles
-
A para-selective C-H amidation of simple arenes with nitriles has been developed. By increasing the amount of arenes, a further meta-selective C-H arylation of the produced amides occurred. Both steric and electronic effects are utilized to control the selectivity, resulting in only para-selective amidation products. The readily available nitriles as amidation reagents instead of amides makes the synthesis of N-arylamides more accessible.
- Xiang, Shi-Kai,Li, Jin-Mei,Huang, He,Feng, Chun,Ni, Hai-Liang,Chen, Xiao-Zhen,Wang, Bi-Qin,Zhao, Ke-Qing,Hu, Ping,Redshaw, Carl
-
p. 3435 - 3440
(2016/01/25)
-
- Base Mediated Synthesis of Alkyl-aryl Ethers from the Reaction of Aliphatic Alcohols and Unsymmetric Diaryliodonium Salts
-
The base mediated coupling of aliphatic alcohol pronucleophiles with unsymmetric diaryliodonium salt electrophiles is described. This metal-free reaction is operationally simple, proceeds at mild temperature, and displays broad substrate scope to generate industrially important alkyl-aryl ethers in moderate to excellent yield. The synthetic utility of these reactions is demonstrated, and aspects of sustainability are highlighted by the use of unsymmetric aryl(mesityl)iodonium arylating reagents.
- Sundalam, Sunil K.,Stuart, David R.
-
p. 6456 - 6466
(2015/06/30)
-
- Metal-free n -arylation of secondary amides at room temperature
-
The arylation of secondary acyclic amides has been achieved with diaryliodonium salts under mild and metal-free conditions. The methodology has a wide scope, allows synthesis of tertiary amides with highly congested aryl moieties, and avoids the regioselectivity problems observed in reactions with (diacetoxyiodo)benzene.
- Tinnis, Fredrik,Stridfeldt, Elin,Lundberg, Helena,Adolfsson, Hans,Olofsson, Berit
-
supporting information
p. 2688 - 2691
(2015/06/16)
-
- Aerobic oxidative α-iodination of carbonyl compounds using molecular iodine activated by a nitrate-based catalytic system
-
The novel reaction system comprising air/NH4NO3(cat.)/I2/H2SO4(cat.)is introduced as a simple, safe, cheap, efficient, and regioselective mediator for direct aerobic oxidative α-iodination of aryl, heteroaryl, alkyl, and cycloalkyl methyl ketones. The reaction system enabled the moderate to quantitative regioselective iodination of a large range of different methyl ketone derivatives including those bearing oxidizable heteroatom (S, N) substituents. Several activated aromatic compounds were also efficiently and selectively iodinated. The practical applicability of the presented reaction system was shown on 20 mmol scale under ambient pressure and 100% conversion of substrate was achieved.
- Prebil, Rok,Stavber, Stojan
-
supporting information
p. 5643 - 5647
(2014/12/11)
-
- Efficient and direct iodination of alkyl benzenes using polymer/HIO4 and I2 under mild condition
-
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
-
p. 305 - 308
(2014/06/24)
-
- An in situ acidic carbon dioxide/glycol system for aerobic oxidative iodination of electron-rich aromatics catalyzed by Fe(NO3)3·9H2O
-
An environmentally benign CO2/glycol reversible acidic system was developed for the iron(iii)-catalyzed aerobic oxidative iodination of electron-rich aromatics without the need for any conventional acid additive or organic solvent. Notably, moderate to high isolated yields (up to 97%) of the aryl iodides were attained with comparable regioselectivity when ferric nitrate nonahydrate was used as the catalyst with molecular iodine under 1 MPa of CO2.
- Ma, Ran,Huang, Cheng-Bin,Liu, An-Hua,Li, Xue-Dong,He, Liang-Nian
-
p. 4308 - 4312
(2015/01/08)
-
- Copper-catalyzed intermolecular C-H amination of (Hetero)arenes via transient unsymmetrical λ3-iodanes
-
A one-pot two-step method for intermolecular C-H amination of electron-rich heteroarenes and arenes has been developed. The approach is based on a room-temperature copper-catalyzed regioselective reaction of the in situ formed unsymmetrical (hetero)aryl-λ3-iodanes with a wide range of primary and secondary aliphatic amines and anilines.
- Sokolovs, Igors,Lubriks, Dmitrijs,Suna, Edgars
-
supporting information
p. 6920 - 6928
(2014/06/09)
-
- Iodine(I) reagents in hydrochloric acid-catalyzed oxidative iodination of aromatic compounds by hydrogen peroxide and iodine
-
Hydrochloric acid activates the oxidative iodination of aromatic compounds with the iodine- hydrogen peroxide system through the formation of an iodine(I) compound as the iodinating reagent. Activation with hydrochloric acid is more powerful than that with sulfuric acid. The formation of dichloroiodic(I) acid (HICl2) with various forms of hydrogen peroxide was followed using UV spectroscopy. The HICl2 was used as the iodinating reagent. In the preparative oxidative iodinaton of various aromatic compounds, hydrochloric acid was used in a catalytic amount and the iodine(I) reagent was formed in situ with 0.5 equiv. hydrogen peroxide and 0.5 equiv. molecular iodine. Two types of reactivity were observed in oxidative iodination with iodine(I) species catalyzed by hydrochloric acid: in the iodination of anisole 1a better yields of iodination were observed with a smaller amount of hydrochloric acid, while on the contrary 4-tert-butyltoluene 1b gave better yields of iodination upon increasing the amount of hydrochloric acid. Reactivity was further manipulated by the choice of the solvent (MeCN, trifluoroethanol, hexafluoro-2-propanol). Copyright
- Bedrac, Leon,Iskra, Jernej
-
supporting information
p. 1243 - 1248
(2013/06/27)
-
- Synthesis and reactivity of aryl(alkynyl)iodonium salts
-
The first practical, yet simple, preparation of aryl(alkynyl)iodonium trifluoroacetate salts is described. The generic nature of this synthetic method has allowed the production of a range of aryl(alkynyl)iodonium trifluoroacetate salts with independent variation of both the alkynyl and aryliodo groups in yields of 30-85 %. Application of these new reagents to the synthesis of a series of 2-arylfuro[3,2-c]pyridines (40-64 %) highlights the potential of this class of materials as precursors to bioactive heterocyclic structures. These experiments have also demonstrated that, in this case, the effect of the aryliodo group on the reaction is negligible.
- Dixon, Luke I.,Carroll, Michael A.,Gregson, Thomas J.,Ellames, George J.,Harrington, Ross W.,Clegg, William
-
supporting information
p. 2334 - 2345
(2013/05/21)
-
- Mild and selective organocatalytic iodination of activated aromatic compounds
-
We describe an organocatalytic iodination of activated aromatic compounds using 1,3-diiodo-5,5-dimethylhydantoin (DIH) as the iodine source with thiourea catalysts in acetonitrile. The protocol is applicable to a number of aromatic substrates with significantly different steric and electronic properties. The iodination is generally highly regioselective and provides high yields of isolated products. NMR kinetic investigations conducted in THF-d 8indicate the role of sulfur in the thiourea motif as a nucleophile that is assisted by H-bonding in the key steps of the reaction. Georg Thieme Verlag Stuttgart . New York.
- Jakab, Gergely,Hosseini, Abolfazl,Hausmann, Heike,Schreiner, Peter R.
-
supporting information
p. 1635 - 1640
(2013/07/27)
-
- Metal-free synthesis of aryl ethers in water
-
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
-
supporting information
p. 6070 - 6073
(2014/01/06)
-
- Oxyarylation and aminoarylation of styrenes using photoredox catalysis
-
A three-component coupling of styrenes is reported, using photoredox catalysis to achieve simultaneous arylation and C-O or C-N bond formation across the styrene double bond.
- Fumagalli, Gabriele,Boyd, Scott,Greaney, Michael F.
-
supporting information
p. 4398 - 4401
(2013/09/24)
-
- Aryl radical formation by copper(I) photocatalyzed reduction of diaryliodonium salts: NMR Evidence for a CuII/CuI mechanism
-
Photocatalyzed reduction of diaryliodonium salts was achieved by using [Cu(dpp)2][PF6] as a photoactive complex and DIPEA as a reductive quench. The application of a copper catalyst allows the generation of aryl radicals under mild conditions and maintains their reactivity for C-C bond formation processes.
- Baralle, Alexandre,Fensterbank, Louis,Goddard, Jean-Philippe,Ollivier, Cyril
-
supporting information
p. 10809 - 10813
(2013/09/02)
-
- Potassium 4-iodylbenzenesulfonate: Preparation, structure, and application as a reagent for oxidative iodination of arenes
-
A new hypervalent iodine(V) compound, potassium 4-iodylbenzenesulfonate, was prepared by the oxidation of 4-iodobenzensulfonic acid with Oxone in water. This potassium salt can be further converted into 4-iodylbenzenesulfonic acid by treatment with the acidic form of Amberlyst 15 in water. A single-crystal X-ray structure of potassium 4-iodylbenzenesulfonate revealed the presence of polymeric chains in the solid state due to a combination of numerous intra- and intermolecular interactions. Potassium 4-iodylbenzenesulfonate will likely find many practical applications as a thermally stable and water-soluble hypervalent iodine-based oxidant, particularly useful as a reagent for oxidative iodination of aromatic substrates. This reagent can be effectively recovered from the reaction mixture (92 % recovery) by treatment of the aqueous layer with Oxone at 60°C for 2 h, followed by filtration of the precipitate. A new hypervalent iodine(V) compound, potassium 4-iodylbenzenesulfonate, was prepared by oxidation of 4-iodobenzenesulfonic acid with Oxone in water. This new reagent promises many practical applications as a thermally stable, water-soluble and recyclable hypervalent iodine oxidant, particularly useful for oxidative iodination of aromatic substrates.
- Yusubov, Mekhman S.,Yusubova, Roza Y.,Nemykin, Victor N.,Maskaev, Andrey V.,Geraskina, Margarita R.,Kirschning, Andreas,Zhdankin, Viktor V.
-
p. 5935 - 5942,8
(2020/09/02)
-
- Aromatic iodination using N-iodosaccharin in room temperature ionic liquids
-
More reactive iodination conditions have been developed that combine the use of room temperature ionic liquids with N-iodosaccharin. Using these reaction conditions, even very modestly activated arenes such as toluene can be iodinated in good yield under very mild conditions.
- Bailey, Lindsey,Handy, Scott T.
-
experimental part
p. 2413 - 2414
(2011/05/09)
-
- Efficient iodination of aromatic compounds using potassium ferrate supported on montmorillonite
-
Potassium ferrate impregnated on montmorillonite is a mild, cheap, and non-toxic reagent for the iodination of phenols, including naphthol, aromatic amines, and heterocyclic substrates in fair to excellent yields by a simple isolation procedure.
- Keipour, Hoda,Khalilzadeh, Mohammad A.,Mohtat, Bita,Hosseini, Abolfazl,Zareyee, Daryoush
-
experimental part
p. 1427 - 1430
(2012/06/01)
-
- Iodonium salts are key intermediates in Pd-catalyzed acetoxylation of pyrroles
-
A mild, room-temperature Pd-catalyzed acetoxylation of pyrroles with phenyliodonium acetate is described. The acetoxylation was found to proceed via the initial formation of pyrrolyl(phenyl)iodonium acetates, which were converted to acetoxypyrroles in the presence of Pd(OAc)2. The acetoxylation could also be carried out as a one-pot sequential procedure without the isolation of the intermediate iodonium salts.
- Lubriks, Dmitrijs,Sokolovs, Igors,Suna, Edgars
-
body text
p. 4324 - 4327
(2011/10/05)
-
- Metal-free 1,5-regioselective azide-alkyne [3+2]-cycloaddition
-
[3+2]-cycloaddition reactions of aromatic azides and silylated alkynes in aqueous media yield 1,5-disubstituted-4-(trimethyl-silyl)-1H-1,2,3-triazoles. The formation of the 1,5-isomer is highly favored in this metal-free cycloaddition, which could be proven by 1D selective NOESY and X-ray investigations. Additionally, DFT calculations corroborate the outstanding favoritism regarding the 1,5-isomer. The described method provides a simple alternative protocol to metal-catalyzed "click chemistry" procedures, widening the scope for regioselective heavy-metal-free synthetic applications.
- Kloss, Florian,Koehn, Uwe,Jahn, Burkhard O.,Hager, Martin D.,Goerls, Helmar,Schubert, Ulrich S.
-
supporting information; experimental part
p. 2816 - 2824
(2012/06/01)
-
- Gold-catalyzed halogenation of aromatics by N-halosuccinimides
-
(Chemical Equation Presented) Golden bromination: A highly efficient and mild AuCl3-catalyzed bromination of aromatic rings with Nbromosuccinimide (NBS) has been developed. This method works with a low catalyst loading (down to 0.01 mol %) and can be combined with transition metal catalyzed transformations to deliver various aryl products.
- Mo, Fanyang,Yan, Jerry Mingtao,Qiu, Di,Li, Fei,Zhang, Yan,Wang, Jianbo
-
supporting information; scheme or table
p. 2028 - 2032
(2010/06/17)
-
- Ecofriendly iodination of activated aromatics and coumarins using potassium iodide and ammonium peroxodisulfate
-
An environmentally benign protocol for the iodination of activated aromatics, such as phenols, anilines, and hydroxycou-marins, using inexpensive commercially available potassium iodide and ammonium peroxodisulfate (1:2.5 molar equivalents per mole of substrate) in aqueous methanol (MeOH-H 2O, 6:1) at room temperature has been developed. The protocol provides for ortho-selective monoiodination as the predominant product without added acid and it is compatible with a number of common oxidizible functional groups, such as formyl, benzylic C-H, aromatic amines and hydroxymethyl. Good to acceptable yields of monoiodinated products in acceptable reaction times and exclusive ortho-iodination for 7-hydroxycoumarins, despite the presence of vinylogous electronrich C3, are some of the key advantageous features of the method. Georg Thieme Verlag Stuttgart.
- Ganguly, Nemai C.,Barik, Sujoy Kumar,Dutta, Sanjoy
-
experimental part
p. 1467 - 1472
(2010/09/16)
-
- NO-CARRIER-ADDED NUCLEOPHILIC [F-18] FLUORINATION OF AROMATIC COMPOUNDS
-
Phenyliodonium ylide derivatives substituted with electron donating as well as electron withdrawing groups on the aromatic ring are shown for use as precursors in aromatic nucleophilic substitution reactions. The iodonium ylide group is substituted by nucleophiles such as halide ions to provide the corresponding haloaryl derivatives. No- carrier-added [F-18]fluoride ion exclusively substitutes the iodonium ylide moiety in these derivatives and provides high specific activity F- 18 labeled fluoro derivatives. Protected L-dopa-6-iodonium ylide derivative have been synthesized as a precursors for the preparation of no-carrier-added 6-[F- 18]fluoro-L-dopa. The iodonium ylide group in this L-dopa.derivative is nucleophilically substituted by no-carrier-added [F-18]fluoride ion to provide a [F-18]fluoro intermediates which upon acid hydrolysis yielded 6-[F- 18]fluoro-L-dopa.
- -
-
Page/Page column 11-12
(2010/11/03)
-
- IBX-I2 redox couple for facile generation of IOH and I +: Expedient protocol for iodohydroxylation of olefins and iodination of aromatics
-
(Chemical Equation Presented) IBX is readily reduced to IBAin the presence of molecular iodine in DMSO to generate hypoiodous acid (IOH), which reacts with a variety of olefins as well as R, β-unsaturated ketones leading to their respective iodohydrins with anti stereochemistry. The same redox chemistry in acetonitrile containing TFA produces iodonium ions for facile iodination of a variety of aromatic compounds in respectable isolated yields.
- Moorthy, Jarugu Narasimha,Senapati, Kalyan,Kumar, Sarvesh
-
supporting information; experimental part
p. 6287 - 6290
(2009/12/08)
-
- Preparation and X-ray structures of 2-[(aryl)iodonio]benzenesulfonates: novel diaryliodonium betaines
-
Herein we present a concise preparation and characterization of 2-[(aryl)iodonio]benzenesulfonates. Determination of the X-ray crystal structure reveals a distorted trigonal bipyramidal molecular geometry about iodine and a pseudo-square geometry within t
- Justik, Michael W.,Protasiewicz, John D.,Updegraff, James B.
-
scheme or table
p. 6072 - 6075
(2010/03/01)
-
- Revealing a second transmetalation step in the Negishi coupling and its competition with reductive elimination: Improvement in the interpretation of the mechanism of biaryl syntheses
-
This paper presents an experimental and theoretical investigation of the Pd-catalyzed Negishi coupling reaction and reveals a novel second transmetalation reaction between an Ar1-Pd-Ar2 species and the organozinc reagent Ar2-ZnX. Understanding of this second step reveals how homocoupling and dehalogenation products are formed. Thus, the second transmetalation generates Ar2PdAr2 and Ar 1ZnCl, which upon reductive elimination and hydrolysis, respectively, give the homocoupling product Ar2-Ar2 and the dehalogenation product Ar1H. The ratio of the cross-coupling product Ar1-Ar2 and the homocoupling product Ar 2-Ar2 is determined by competition between the second transmetalation and reductive elimination steps. This mechanism is further supported by density functional theoretical calculations. Calculations on a series of reactions suggest a strategy in controlling the selectivity of cross-coupling and homocoupling pathways, which we have experimentally verified.
- Liu, Qiang,Lan, Yu,Liu, Jing,Li, Gang,Wu, Yun-Dong,Lei, Aiwen
-
supporting information; experimental part
p. 10201 - 10210
(2009/12/08)
-
- Aerobic oxidative iodination of organic molecules activated by sodium nitrite
-
Aerobic oxidative iodination activated by sodium nitrite occurs effectively and selectively with 100% iodine atom economy with air as the oxidant. Silica-supported sulfuric acid was used for the activation of the catalyst and iodination. Thus, I2/NaNO2/air/silica-supported H2SO4 in acetonitrile iodinated aromatics, ketones and aldehydes effectively at ambient temperature.
- Iskra, Jernej,Stavber, Stojan,Zupan, Marko
-
p. 893 - 895
(2008/09/17)
-
- Iodination of activated aromatic compounds using sodium peroxodisulfate and iodine: An efficient way to iodinate alkylated calix[4]arenes
-
A simple method for the iodination of activated arenes, using molecular iodine and sodium peroxodisulfate as the oxidant, is presented. The reaction is conducted in the presence of catalytic amounts of tetramethylammonium iodide as a phase-transfer catalyst in acetonitrile. For non-polar substances, which are not soluble in pure acetonitrile such as calix[4]arenes bearing long alkyl chains, a modified reaction is introduced. In this case the phase-transfer catalyst is changed to methyltriphenylphosphonium peroxodisulfate. Chloroform as a cosolvent mediates solubility. Furthermore, we show that the slightly basic conditions obtained upon the addition of sodium bicarbonate have a beneficial effect on the yield. Georg Thieme Verlag Stuttgart.
- Barton, Olaf G.,Mattay, Jochen
-
p. 110 - 114
(2008/09/20)
-
- 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
-
(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.
-
p. 316 - 319
(2008/09/17)
-
- Solvent-free iodination of arenes using iodine-silver nitrate combination
-
A simple and environmentally safe general method of iodination of aromatic substrates under sovent-free conditions using the I2/AgNO3 combination in a solid state is reported. Both activated and deactivated aromatic compounds afford the respective aryl iodides in generally high yields (80-90%). Copyright Taylor & Francis Group, LLC.
- Yusubov, Mekhman S.,Tveryakova, Elena N.,Krasnokutskaya, Elena A.,Perederyna, Irina A.,Zhdankin, Viktor V.
-
p. 1259 - 1265
(2008/02/01)
-
- FeCl3-catalyzed alkenylation of simple arenes with aryl-substituted alkynes
-
An addition of electron-rich arenes to aryl-substituted alkynes to form 1,1-diaryl alkenes is carried out in the presence of FeCl3 as catalyst under mild conditions.
- Li, Ruoshi,Wang, Sunewang R.,Lu, Wenjun
-
p. 2219 - 2222
(2008/02/05)
-
