- Conveniently Synthesized Butterfly-Shaped Bitriphenylenes and their Application in Solution-Processed Organic Field-Effect Transistor Devices
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Various π-extended new bitriphenylene derivatives (both conformationally-free and conformation-locked) have been successfully synthesized by a facile Scholl oxidative cyclodehydrogenation method in good to excellent yields. Their optical properties in solution and film states reveal possibility for self-ordering. The molecular packing in solid-state demonstrates favorable π–π stacking as well as weak intermolecular interactions leading to face-to-face or slipped-stack arrangements. Besides, these butterfly-shaped large bitriphenylenes display near-UV absorption, excellent photochemical, thermal, and electrochemical stabilities. The all-organic anneal-free transparent FETs fabricated from solution-processable bitriphenylenes showcase significant improvement (ca. 4 orders of magnitude higher) in charge transporting abilities (μh: from ca. 10–7 to 10–3 cm2/(Vs)) when compared to model triphenylene. The fabricated FETs unveil excellent air stability (> 1 year under atmospheric conditions) highlighting the utility of these novel link-locked triphenylene skeletons in organic electronics.
- Chennamkulam, Ajith Mithun,Dutta, Soumya,Karunakaran, Logesh,Paneer, Shyam Vinod Kumar,Ramakrishna, Jagarapu,Subramanian, Venkatesan,Venkatakrishnan, Parthasarathy
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Read Online
- Synthesis, characterization, and systematic structure–property investigation of a series of carbazole–thiophene derivatives
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A series of carbazole–thiophene oligomers linked at the 3,6-positions of the carbazole fragment of 4,4′-bis(carbazol-9-yl)biphenyl (CBP) and 4,4′-bis(carbazol-9-yl)-2,2′-dimethylbiphenyl (CDBP) with systematically elongated molecular lengths were synthesized via the Suzuki–Miyaura and Ullmann coupling reactions. Their electronic properties were studied by UV-Vis, cyclic voltammetry, and theoretical calculations. The coupling of CBP and CDBP with thiophene and bi- and terthiophene residues stabilized the HOMO and LUMO energy levels. The absorption and emission spectra exhibited a gradual red shift. The compounds with oligothiophene units had greatly decreased band gaps compared with CBP and CDBP. Therefore, these units may be introduced into the backbone of π-conjugated small molecules to develop new materials with low band gaps that may have potential applications in optoelectronics.
- Damit,Nordin,Ariffin,Sulaiman
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Read Online
- Modular Approach to Kekulé Diradicaloids Derived from Cyclic (Alkyl)(amino)carbenes
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A modular approach for the synthesis of Kekulé diradicaloids is reported. The key step is the insertion of a carbene, namely, a cyclic (alkyl)(amino)carbene (CAAC), into the C-H bonds of two terminal alkynes linked by a spacer. Subsequent hydride abstraction, followed by two-electron reduction of the corresponding bis(iminium) salts, affords the desired diradicaloids. This synthetic route readily allows for the installation of communicating spacers, featuring different degrees of aromaticity and lengths, and gives the possibility of generating unsymmetrical compounds with two different CAACs. Electron paramagnetic resonance (EPR), NMR, UV-vis, and X-ray studies in combination with quantum-chemical calculations give insight into the electronic nature of the deeply colored Kekulé diradicaloids. They feature a singlet ground state with varying degrees of diradical character in combination with small singlet/triplet gaps. Upon lengthening of the spacer, the properties of the compounds approach those of monoradicals in which steric protection of the propargyl radical moiety is necessary to inhibit decomposition pathways. Most of these diradicaloids are stable at room temperature, both in solution and in the solid state, but are highly oxygen-sensitive. They represent the first diradicaloids derived from iminium salts.
- Hansmann, Max M.,Melaimi, Mohand,Munz, Dominik,Bertrand, Guy
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Read Online
- Visible Light Induced Aerobic Coupling of Arylboronic Acids Promoted by Hydrazone
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A visible-light-induced oxidative coupling of arylboronic acids has been developed for the synthesis of biaryls. The reaction that employs polydentate hydrazones as the bifunctional catalyst works smoothly under room temperature. It is compatible with a w
- Xia, Hongyu,Wang, Ganghu,Zhao, Dongbo,Zhu, Chunyin
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supporting information
p. 922 - 929
(2022/02/10)
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- Silk?Fibroin-Supported Palladium Catalyst for Suzuki-Miyaura and Ullmann Coupling Reactions of Aryl Chlorides
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Recently, we have reported the preparation of a silk fibroin-supported Palladium catalyst (Pd/SF) and its use in the Suzuki-Miyaura cross-coupling of aryl iodides. Since its synthetic applicability and structural features are still far from being fully ex
- Albano, Gianluigi,Farinola, Gianluca M.,Giannini, Cinzia,Musio, Roberta,Omenetto, Fiorenzo G.,Rizzo, Giorgio,Sibillano, Teresa
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supporting information
(2022/02/03)
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- "benchtop" Biaryl Coupling Using Pd/Cu Cocatalysis: Application to the Synthesis of Conjugated Polymers
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Typically, Suzuki couplings used in polymerizations are performed at raised temperatures in inert atmospheres. As a result, the synthesis of aromatic materials that utilize this chemistry often demands expensive and specialized equipment on an industrial scale. Herein, we describe a bimetallic methodology that exploits the distinct reactivities of palladium and copper to perform high yielding aryl-aryl dimerizations and polymerizations that can be performed on a benchtop under ambient conditions. These couplings are facile and can be performed by simple mixing in the open vessel. To demonstrate the utility of this method in the context of polymer synthesis: polyfluorene, polycarbazole, polysilafluorene, and poly(6,12-dihydro-dithienoindacenodithiophene) were created at ambient temperature and open to air.
- Minus, Matthew B.,Moor, Sarah R.,Pary, Fathima F.,Nirmani,Chwatko, Malgorzata,Okeke, Brandon,Singleton, Josh E.,Nelson, Toby L.,Lynd, Nathaniel A.,Anslyn, Eric V.
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supporting information
p. 2873 - 2877
(2021/05/05)
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- Synergistic Activities in the Ullmann Coupling of Chloroarenes at Ambient Temperature by Pd-Supported Calcined Ferrocenated La2O3
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Novel palladium-doped nanoparticles have been explored to serve as the first metal oxide-derived heterogeneous catalyst for Ullmann reaction of chloroarenes under mild condition (34?°C). This heterogeneous catalyst exhibited high catalytic activity towards the Ullmann homocoupling of chloroarenes into a series of useful symmetrically biaryl products with good to excellent yields in the presence of ethanol and NaOH, thereby leading to green and economical Ullmann reaction. The produced nanoparticles were successfully characterized by various techniques including PXRD, XPS, HRTEM, SEM-EDS, BET, TGA techniques, elemental mapping analysis and ICP-OES. Interestingly, based on characterization and experimental data, a reasonable mechanism has been proposed. Also, the formation of aryl methyl ketone as a by-product has been further confirmed by isotopic labelling experiments that the acetyl moiety is derived from ethanol. Moreover, the catalyst was stable and could be easily reused up to 5 times under atmospheric air without suffering significant loss in catalytic activity.
- Chumkaeo, Peerapong,Poonsawat, Thinnaphat,Meechai, Titiya,Somsook, Ekasith
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- Heck arylation of allyl alcohol catalyzed by Pd(0) nanoparticles
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Pd(0) nanoparticles ca. 2 nm in diameter were obtained by the reduction of PdCl2 and Pd(OAc)2 in water at 80 °C in the presence of a PVP-stabilizing polymer. Pd(0) NPs were successfully used in the Heck coupling of allyl alcohol with iodo- and bromobenzenes. Iodobenzenes reacted under solventless conditions or in DMF solution producing 3-arylpropanals and 2-arylpropanals as the main products. The same products were obtained in the reaction of bromobenzene in TBAB as the reaction medium. The stability of Pd(0) NPs was evidenced in recycling experiments. Similar Heck coupling results were also obtained with the palladium compounds PdCl2(cod) and Pd(OAc)2 under the same conditions.
- Tarnowicz, Stanis?awa,Alsalahi, Waleed,Mieczyńska, Ewa,Trzeciak, Anna M.
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p. 5605 - 5612
(2017/08/26)
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- Palladium-catalyzed reductive homocoupling of aryl sulfonates via cleavage of C─O bond at room temperature
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Palladium-catalyzed reductive homocoupling of aryl sulfonates has been successfully achieved under mild conditions. This transformation is a new method for the homocoupling reaction of aryl sulfonates at room temperature via the cleavage of C─O bonds, thus providing an alternative synthesis of symmetric biaryls. The reported reductive homocoupling reaction is tolerant of many common functional groups regardless of electron-donating or electron-withdrawing nature, making this newly developed transformation important for complementing Ullmann coupling. Experimental Section. Typical procedure for the products.
- Zhong, Shuangling,Chen, Mengxin,Liu, Ge,Sun, Chenggang,Liu, Wencong
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- Rapid Ligand-Free Base-Accelerated Copper-Catalyzed Homocoupling Reaction of Arylboronic Acids
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A rapid, ligand-free, base-accelerated, copper-catalyzed homocoupling reaction of (het)arylboronic acids is presented. A -CuCl2·2H2O/Na2CO3-based catalyst enabled the formation of bi(het)aryl compounds by a homocoupling process in moderate to excellent yields (72-97%) within 15 minutes. A mechanism for the copper-catalyzed base-accelerated reaction is proposed.
- Cao, Ya-Nan,Tian, Xin-Chuan,Chen, Xing-Xiu,Yao, Yun-Xin,Gao, Feng,Zhou, Xian-Li
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supporting information
p. 601 - 606
(2017/03/11)
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- Synthesis of Novel Derivatives of Carbazole-Thiophene, Their Electronic Properties, and Computational Studies
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A series of carbazole-thiophene dimers, P1-P9, were synthesized using Suzuki-Miyaura and Ullmann coupling reactions. In P1-P9, carbazole-thiophenes were linked at the N-9 position for different core groups via biphenyl, dimethylbiphenyl, and phenyl. Electronic properties were evaluated by UV-Vis, cyclic voltammogram, and theoretical calculations. Particularly, the effects of conjugation connectivity on photophysical and electrochemical properties, as well as the correlation between carbazole-thiophene and the core, were studied. Carbazole connecting with thiophenes at the 3,6-positions and the phenyl group as a core group leads to increased stabilization of HOMO and LUMO energy levels where the bandgap (Δ E) is significantly reduced.
- Damit,Nordin,Ariffin,Sulaiman
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- 4,4'-diiodobiphenyl preparation method
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The invention provides a 4,4'-diiodobiphenyl preparation method, and belongs to the field of chemical industry synthesis. According to the present invention, a direct iodination method is used to prepare the product, and a composite catalyst concentrated sulfuric acid and concentrated hydrochloric acid mixing solution is used to catalyze the reaction process so as to reduce the reaction temperature, reduce the reaction time, and reduce the amount of iodine; the specific scheme comprises: adding glacial acetic acid, deionized water and a composite catalyst concentrated sulfuric acid and concentrated hydrochloric acid mixing solution to a reaction bottle at a room temperature, adding biphenyl, iodine and an oxidizing agent ammonium persulfate under a stirring condition, heating to a temperature of 75-90 DEG C, maintaining a reaction for 1.5-2 h, cooling, filtering, and recrystallizing to obtain the pure product, wherein the purity of the product is up to 99.8%; and the method has advantages of mild reaction, high conversion rate, safety and environmental protection, and is suitable for industrial production.
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Paragraph 0008
(2017/06/10)
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- A method of compounding aromatic hydrazine synthesis symmetry biphenyl
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The invention discloses a method for synthesizing symmetrical biphenyl from aromatic hydrazine, which belongs to the field of organic synthesis. The method comprises the following steps: separately adding the aromatic hydrazine, inorganic base and a palladium catalyst into a reaction tube filled with a proper amount of a solvent, wherein the mol ratio of the aromatic hydrazine to the inorganic base to the palladium catalyst is 50: 50: 1; carrying out heating to 50 DEG C and magnetic stirring for 3 h; after completion of a reaction, carrying out cooling to room temperature; and then carrying out filtering, subjecting the solvent to spinning drying and carrying out recrystallization so as to obtain the symmetrical biphenyl. According to the method, reactive denitrification groups are removed in the form of nitrogen, which is green and free of pollution; the reaction takes air as an oxidation agent to promote oxidation denitrification, does not need any gas protection, and can be performed very well in the air without producing any by-product; and symmetrical biphenyl compounds can be prepared from cheap and easily-available aromatic hydrazine, so the method has high practicability and selectivity, and the product yield is normally much higher than the product yield reported in the literature.
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Paragraph 0030-0032
(2018/01/14)
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- Synthesis of substituted 4,4′-dihalobiphenyls and their use for the preparation of isomeric bis(carbazolyl)biphenyls
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Model compounds of some polychlorobiphenyl congeners, viz., 4,4′-dihalobiphenyls, were synthesized. These compounds can be successfully utilized by a chemical method for the in situ generation of arynes followed by the reaction with carbazole in order to prepare appropriate bis(carbazolyl)biphenyls as components for molecular electronics and OLED devices.
- Kovalev,Pavlyuk,Zaripov,Zyryanov,Kopchuk,Rusinov,Chupakhin
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p. 1978 - 1981
(2016/05/11)
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- Pd-catalyzed homocoupling of arylhydrazines via C - N cleavage under O 2
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An efficient and simple synthetic method for biaryl synthesis was developed using Pd(OAc)2 as catalyst from aryl hydrazides under O2. Various biaryls were synthesized in good yields, offering an expedient protocol for the synthesis of symmetrical biaryl molecules via C - N cleavage. The reactions were performed in component solvent of toluene and acetone without using any pro-oxidant. Copyright
- Yao, Peng
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p. 194 - 197
(2014/03/21)
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- Aryl diazonium nanomagnetic sulfate and potassium iodide: An iodination process
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A simple and efficient procedure for the synthesis of iodoarenes is developed which involves the sequential diazotization-iodination of aromatic amines with sodium nitrite, nanomagnetic supported sulfonic acid, and potassium iodide under solvent-free conditions at room temperature.
- Kolvari, Eskandar,Amoozadeh, Ali,Koukabi, Nadiya,Otokesh, Somayeh,Isari, Mohsen
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supporting information
p. 3648 - 3651
(2014/06/23)
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- The homocoupling of arylsulfonylhydrazides by palladium-catalysed desulfonation in air
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A simple and efficient preparation of biaryl derivatives from arylsulfonyl hydrazides has been developed using Pd(OAc)2 as the catalyst in a mixed solvent of DMA and THF and without the use of any ligand and base.
- Zhang, Wei,Zhao, Baoli,Li, Ke
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p. 674 - 676
(2014/01/17)
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- Ferrous salt-promoted homocoupling of arenediazonium tetrafluoroborates under mild conditions
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A simple and efficient protocol has been developed for the synthesis of various symmetrical biaryls in good to excellent yields from the homocoupling reactions of arenediazonium salts with ferrous salt in carbon tetrachloride solution under mild reaction conditions. Moreover, the novel homocoupling has been demonstrated to proceed via an electron transfer reaction mechanism.
- Ding, Yiyuan,Song, Qingbao,Cheng, Kai,Qi, Chenze
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p. 6269 - 6272,4
(2012/12/11)
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- Homocoupling of arylboronic acids catalyzed by simple gold salts
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A range of arylboronic acids undergo a homocoupling reaction in the presence of catalytic amount of gold salts to yield symmetrical biaryls. Alkenylboronic acids, arylboronic esters, and arylborates also participate in the gold-catalyzed homocoupling reaction.
- Matsuda, Takanori,Asai, Taro,Shiose, Shigeru,Kato, Kotaro
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experimental part
p. 4779 - 4781
(2011/10/05)
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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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- Homocoupling of arylboronic acids catalyzed by 1,10-phenanthroline-ligated copper complexes in air
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The efficient homocoupling of arylboronic acids was achieved by using the catalytic combination of inexpensive copper salts and 1,10-phenanthroline as aligand. The homocoupling reaction proceeds at ambient temperature in air without any additives such as base or oxidant. This method tolerates various substituents on the arylboronic acids such as halogens, carbonyls, and a nitro group. As a result, 25 symmetrical biaryls were obtained from readily available arylboronic acids in 19-92% isolated yields. A binuclear (μ- hydroxido)copper complex is assumed as the catalytically active species, which undergoes efficient transmetalation with arylboronic acids to produce dinuclear arylcopper complexes. The binuclear structure is assumed to be essential for the bimetallic reductive elimination of biaryls as well as the oxidative restoration of the catalyst. Wiley-VCH Verlag GmbH & Co, KGaA.
- Kirai, Naohiro,Yamamoto, Yoshihiko
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experimental part
p. 1864 - 1867
(2009/08/17)
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- 1,3-Diiodo-5,5-dimethylhydantoin-An efficient reagent for iodination of aromatic compounds
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1,3-Diiodo-5,5-dimethylhydantoin in organic solvents successfully iodinates alkylbenzenes, aromatic amines, and phenyl ethers. The reactivity of electrophilic iodine is controlled by acidity of the medium. Superelectrophilic iodine generated upon dissolution of 1,3-diiodo-5,5-dimethylhydantoin in sulfuric acid readily reacts with electron-deficient arenes at 0 to 20°C with formation of the corresponding iodo derivatives in good yields. The structure of electrophilic iodine species generated from 1,3-diiodo-5,5- dimethylhydantoin in sulfuric acid is discussed.
- Chaikovskii,Filimonov,Funk,Skorokhodov,Ogorodnikov
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p. 1291 - 1296
(2008/03/27)
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- PROCESS FOR PRODUCING AROMATIC IODINE COMPOUND
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A process for producing an aromatic iodine compound. It has advantages of ease of handling and high safety. By the process, the reaction product having an excellent colour tone can be produced in a high yield. The process for aromatic iodine compound production is characterized by introducing an aromatic compound and an active iodizing agent into a flow-through type reactor equipped with a high-speed mixer to continuously replace hydrogen atoms of the aromatic nucleus of the aromatic compound with iodine atoms.
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- A new, one-step, effective protocol for the iodination of aromatic and heterocyclic compounds via aprotic diazotization of amines
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We have developed a convenient one-step preparation of aromatic and some heterocyclic iodides by the sequential diazotization-iodination of the aromatic amines with a KI/NaNO2/p-TsOH system in acetonitrile at room temperature. This method has general character and allows aryl iodides with either donor or acceptor substituents in various positions to be obtained from the corresponding amines in 50-90% yield. Georg Thieme Verlag Stuttgart.
- Krasnokutskaya, Elena A.,Semenischeva, Nadya I.,Filimonov, Victor D.,Knochel, Paul
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- Biphenyl- and terphenyl-based recyclable organic trivalent iodine reagents
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Biphenyl- and terphenyl-based recyclable trivalent iodine reagents, such as 4-bromo-4′-(diacetoxyiodo)biphenyl, 4,4′-bis(diacetoxyiodo)biphenyl, 1,4-bis[4-(diacetoxyiodo)phenyl]benzene, 4-bromo-4′-[(hydroxy)(tosyloxy)iodo]biphenyl, 4,4′-bis[(hydroxy)(tosyloxy)iodo]biphenyl, were simply prepared and their reactivities for the oxidative rearrangement of ketones to esters, TEMPO-mediated oxidation of alcohols to aldehydes or ketones, oxidative dealkylation of N-alkylsulfonamides to sulfonamides, and α-tosyloxylation of ketones were compared with p-(diacetoxyiodo)toluene and p-[(hydroxy)(tosyloxy)iodo]toluene to show the same reactivities and, moreover, the biphenyl- and terphenyl-based iodoarenes formed were recovered by simple filtration of the reaction mixture in every reaction. Thus, these biphenyl- and terphenyl-based trivalent iodine reagents can be used as the recyclable reagents.
- Moroda, Atsushi,Togo, Hideo
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p. 12408 - 12414
(2007/10/03)
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- PROCESS FOR PRODUCING AROMATIC IODINE COMPOUND
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A process for producing an aromatic iodine compound. It has advantages of ease of handling and high safety. By the process, the reaction product having an excellent color tone can be produced in a high yield. The process for aromatic iodine compound production is characterized by introducing an aromatic compound and an active iodizing agent into a flow-through type reactor equipped with a high-speed mixer to continuously replace hydrogen atoms of the aromatic nucleus of the aromatic compound with iodine atoms.
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Page/Page column 19-20; 25
(2008/06/13)
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- Synthesis of medium-ring and iodinated biaryl compounds by organocuprate oxidation
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(Chemical Equation Presented) A biaryl banquet! Biphenyls with four ortho substituents, heteroaromatic compounds, iodinated biaryls, and medium rings containing biaryls are all readily synthesized by organocuprate oxidation. The utility of this new methodology is illustrated by the efficient synthesis of the medium-ring core of sanguiin H-5 (see scheme).
- Surry, David S.,Su, Xianbin,Fox, David J.,Franckevicius, Vilius,Macdonald, Simon J. F.,Spring, David R.
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p. 1870 - 1873
(2007/10/03)
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- Synthesis and Functional Properties of Strongly Luminescent Diphenylamino End-Capped Oligophenylenes
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Two novel homologous series of oligophenylenes (OPPs) symmetrically end-capped with diphenylamino groups and asymmetrically end-capped with anthryldiphenylamino groups were successfully synthesized by a convergent approach with use of palladium-catalyzed homo- and cross-coupling of arylboronic acids. The absorption maxima of both diphenylamino end-capped OPP series do not vary with the chain length although the molar absorptivities increase sequentially. On the other hand, the emission maxima slightly shift to longer wavelengths when the phenylene unit increases in the series. All the diphenylamino end-capped oligomers exhibit very large fluorescence quantum yields (81-89%). They also exhibit low first ionization potentials, corresponding to the oxidation of the triarylamino moiety, which are essentially unaffected by the oligomeric length extension. The good thermal stabilities of these oligomers allowed the fabrication of multilayer light-emitting devices and their investigations.
- Li, Zhong Hui,Wong, Man Shing,Tao, Ye,D'Iorio, Marie
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p. 921 - 927
(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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- Iodination and chlorination of aromatic polycyclic hydrocarbons with iodine monochloride in aqueous sulfuric acid
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Polycyclic aromatic hydrocarbons when treated with iodine monochloride in water solutions of sulfuric acid afford iodo-and chloroderivatives. Biphenyl, fluorene, acenaphthene, 1-nitronaphthalene undergo iodination. Naphthalene furnishes a mixture of iodo-and chloroderivatives, prevailing the latter. Anthracene and phenanthrene provide only chlorinated products. The iodine monochloride in the sulfuric acid is a stronger iodinating agent than in acetonitrile.
- Chaikovskii,Filimonov
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p. 1130 - 1133
(2007/10/03)
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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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- Activation of the C-H bond in DMF as a key stage of oxidative addition of aryl iodides to platinum(II) in the system PtCl2-4-DMF
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Reaction of mono- and disubstituted aryl iodides with platinum(II) tetrachloride complexes in DMF results in formation of the corresponding arenes and biaryls. With the substrate present in a large excess, biaryl formation becomes a preferred pathway and proceeds catalytically. The rates of the oxidative addition increase in the series of substituents p-CH3O ≈ m-CH3 2 2, and the Hammett equation with the parameters p +1.3±0.2 and logk0 -4.51 ± 0.08 is obeyed. The kinetic data and the composition of the products are in agreement with a mechanism involving initial formation of a PtCl3 · (CONMe2)2- species as a result of activation of the C-H bond in dimethylformamide by platinum(II), followed by oxidative addition of ArI to this species.
- Bezbozhnaya,Litvinenko,Skripnik,Zamashchikov
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p. 1198 - 1203
(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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- Improved, Acid-catalyzed Iodinating Procedures for Activated Aromatics with (Diacetoxyiodo)benzene as the Oxidant
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Improved procedures for the oxidative, acid-catalyzed iodination of benzene, iodobenzene and several activated aromatics are presented to give mono-, di-, or triiodinated products in 40-82 percent yields. The reactions proceeded at room temperature in the anhydrous systems: arene or hetarene/diiodine/(diacetoxyiodo)benzene (2)/glacial acetic acid/acetic anhydride, acidified with catalytic amounts of concd. (98 percent) H2SO4. Within at most 15 minutes the iodine coloration faded; the following workups are explained. A similar treatment with dibromine gave tribromomesitylene (65 percent), dibromodurene (62 percent), and 2,7-dibromofluoren-9-one (73 percent). A review on the aromatic halogenation reactions with organic trivalent iodine reagents as the oxidants is presented below.
- Kryska, Anna,Skulski, Lech
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p. 2501 - 2517
(2007/10/03)
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- Process for preparing mono-iodinated aromatic compound
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A process for preparing mono-iodinated aromatic compound is disclosed, wherein the process comprises iodinating an aromatic compound, at least two portions of which can be iodinated, in a solvent mixture of water and acetic acid using iodic acid or periodic acid and iodine, wherein the iodic acid or periodic acid and iodine, and the aromatic compound are added in an amount so that the ratio of the atom number of iodine atom to the molecular number of the aromatic compound is less than 1. The process provides a mono-iodinated aromatic compound having high purity in a high yield.
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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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- 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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- An efficient and regioselective direct aromatic iodination using iodine and nitrogen dioxide
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Direct iodination of a variety of aromatic compounds is achieved by using nitrogen dioxide as an oxidant in addition to iodine. The reaction affords aromatic monoidodides m high yields with high para-regioselectivity. 4,4'- Diiodo binuclear compounds are also obtained effectively by controlling the stoichiometry.
- Noda, Yumiki,Kashima, Mikito
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p. 6225 - 6228
(2007/10/03)
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- Aromatic aryl amine polymers
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A polymer of the formula STR1 wherein Φ=phenyl or phenylene b=0, 1, 2 or 3 n=3 or greater.
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- POTASSIUM PERMANGANATE - A CONVENIENT OXIDANT FOR DIRECT IODINATION OF AROMATIC COMPOUNDS.
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The authors propose the use of potassium permanganate for direct iodination of aromatic compounds. They tested an iodination system containing iodine, potassium permanganate, and sulfuric and nitric acids on a large number of aromatic compounds. Experimental results show that it is effective for iodination of benzene, halobenzenes, oxygen-containing arenes, alkylbenzenes, and certain condensed hydrocarbons. Iodide yields are often close to, or even higher than, those obtained with the use of periodic and iodic acids. Potassium permanganate has not been used previously for iodination of aromatic compounds, probably because in absence of additives its activating effect on iodine is very weak. However, the effectiveness of the reaction is raised sharply when sulfuric acid is added to the system. This is due both to the higher degree of ionization of iodine molecules, as the result of which the electrons of the I-I bond become more accessible to the oxidant, and to the higher oxidizing power of potassium permanganate in a strongly acidic medium.
- Chaikovskii,Novikov
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p. 121 - 123
(2007/10/02)
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- A SIMPLE METHOD FOR THE IODINATION OF AROMATIC COMPOUNDS
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The iodine - (trifluoroacetoxyiodo)benzene system is effective for the iodination of aromatic compounds, alkylbenzenes, various polynuclear aromatic hydrocarbons, halogenobenzenes, and some heterocyclic compounds.Trifluoroacetyl hypoiodite, which is a source of electrophilic iodine, is probably formed initially.Trifluoroacetyl hypoiodite can be generated in situ from (diacetoxyiodo)benzene and trifluoroacetic acid.
- Merkushev, E. B.,Yudina, N. D.
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p. 2320 - 2322
(2007/10/02)
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