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In situ Generation of Hypervalent Iodine Reagents for the Electrophilic Chlorination of Arenes
Efficient metal-free methods for the electrophilic chlorination of arenes using PIFA and simple chlorine sources are reported. The in situ formation of PhI(Cl)OCOCF3 from PIFA and KCl is proposed, which resulted in a chlorinating species for moderately activated arenes. Moreover, the in situ formation of PhICl2 from PIFA and TMSCl resulted in an excellent approach for the chlorination of a great variety of arenes (20 examples) in high yields, even when working on a multigram scale.
Granados, Albert,Jia, Zhiyu,del Olmo, Marc,Vallribera, Adelina
p. 2812 - 2818
(2019)
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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)

Chlorination Reaction of Aromatic Compounds and Unsaturated Carbon-Carbon Bonds with Chlorine on Demand
Chlorination with chlorine is straightforward, highly reactive, and versatile, but it has significant limitations. In this Letter, we introduce a protocol that could combine the efficiency of electrochemical transformation and the high reactivity of chlorine. By utilizing Cl3CCN as the chloride source, donating up to all three chloride atom, the reaction could generate and consume the chlorine in situ on demand to achieve the chlorination of aromatic compounds and electrodeficient alkenes.
Liu, Feng,Wu, Na,Cheng, Xu
supporting information
p. 3015 - 3020
(2021/05/05)

Rigid heterocyclic compound, preparation method and application thereof, phosphine-containing sulfonamide compound and preparation method thereof
The invention relates to the field of organic synthesis, in particular to a rigid heterocyclic compound with sulfonyl and pentavalent phosphorus-nitrogen double bonds as shown in the following generalformula (I) and a preparation method and application th
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Paragraph 0195-0198

(2020/09/09)

Triptycenyl Sulfide: A Practical and Active Catalyst for Electrophilic Aromatic Halogenation Using N-Halosuccinimides
A Lewis base catalyst Trip-SMe (Trip = triptycenyl) for electrophilic aromatic halogenation using N-halosuccinimides (NXS) is introduced. In the presence of an appropriate activator (as a noncoordinating-anion source), a series of unactivated aromatic compounds were halogenated at ambient temperature using NXS. This catalytic system was applicable to transformations that are currently unachievable except for the use of Br2 or Cl2: e.g., multihalogenation of naphthalene, regioselective bromination of BINOL, etc. Controlled experiments revealed that the triptycenyl substituent exerts a crucial role for the catalytic activity, and kinetic experiments implied the occurrence of a sulfonium salt [Trip-S(Me)Br][SbF6] as an active species. Compared to simple dialkyl sulfides, Trip-SMe exhibited a significant charge-separated ion pair character within the halonium complex whose structural information was obtained by the single-crystal X-ray analysis. A preliminary computational study disclosed that the πsystem of the triptycenyl functionality is a key motif to consolidate the enhancement of electrophilicity.
Nishii, Yuji,Ikeda, Mitsuhiro,Hayashi, Yoshihiro,Kawauchi, Susumu,Miura, Masahiro
supporting information
p. 1621 - 1629
(2020/02/04)

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)

Cathodic C-H Trifluoromethylation of Arenes and Heteroarenes Enabled by an in Situ-Generated Triflyltriethylammonium Complex
While several trifluoromethylation reactions involving the electrochemical generation of CF3 radicals via anodic oxidation have been reported, the alternative cathodic, reductive radical generation has remained elusive. Herein, the first cathodic trifluoromethylation of arenes and heteroarenes is reported. The method is based on the electrochemical reduction of an unstable triflyltriethylammonium complex generated in situ from inexpensive triflyl chloride and triethylamine, which produces CF3 radicals that are trapped by the arenes on the cathode surface.
Cantillo, David,Jud, Wolfgang,Kappe, C. Oliver,Maljuric, Snjezana
(2019/10/08)

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)

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)

Room temperature C(sp2)-H oxidative chlorination: Via photoredox catalysis
Photoredox catalysis has been developed to achieve oxidative C-H chlorination of aromatic compounds using NaCl as the chlorine source and Na2S2O8 as the oxidant. The reactions occur at room temperature and exhibit exclusive selectivity for C(sp2)-H bonds over C(sp3)-H bonds. The method has been used for the chlorination of a diverse set of substrates, including the expedited synthesis of key intermediates to bioactive compounds and a drug.
Zhang, Lei,Hu, Xile
p. 7009 - 7013
(2017/10/05)

A practical lewis base catalyzed electrophilic chlorination of arenes and heterocycles
A mild phosphine sulfide catalyzed electrophilic halogenation of arenes and heterocycles that utilizes inexpensive and readily available N-halosuccinimides is disclosed. This methodology is shown to efficiently chlorinate diverse aromatics, including simple arenes such as anthracene, and heterocycles such as indoles, pyrrolopyrimidines, and imidazoles. Arenes with Lewis acidic moieties also proved amenable, underscoring the mild nature of this chemistry. Lewis base catalysis was also found to improve several diverse aromatic brominations and iodinations.
Maddox, Sean M.,Nalbandian, Christopher J.,Smith, Davis E.,Gustafson, Jeffrey L.
supporting information
p. 1042 - 1045
(2015/03/30)

An efficient monochlorination of electron-rich aromatic compounds catalysed by ammonium iodide
An efficient monochlorination of electron-rich aromatic compounds is developed, with which a series of regioselective monochlorinated products are obtained in good yields. In the reaction, ammonium iodide is used as catalyst and m-chloroperbenzoic acid is used as the terminal oxidant. Ammonium iodide is first oxidised to hypoiodous acid by m-chloroperbenzoic acid. The in situ generated active iodine species then reacts with the aromatic compound to form the active hypervalent iodine intermediate in two steps and this reacts with lithium chloride to afford eventually the chlorinated compounds.
Min, Zhu,Ying-Guo, Fang
p. 197 - 199
(2014/05/06)

One-pot oximation-Beckmann rearrangement of ketones and aldehydes to amides of industrial interest: Acetanilide, caprolactam and acetaminophen
High yielding one-pot oximation-Beckmann rearrangement of ketones to amides in ktrifluoroacetic acid has been conducted on several ketones and aldehydes. The substrate reactivity showed to depend on both oximation and Beckmann rearrangement reaction rate. In this synthetic procedure, trifluoroacetic acid acts as solvent, acid catalyst and organocatalyst and can be easily recycled.
Aricò, Fabio,Quartarone, Giuseppe,Rancan, Elia,Ronchin, Lucio,Tundo, Pietro,Vavasori, Andrea
p. 47 - 51
(2014/03/21)

Metal and H2O2 free aerobic oxidative aromatic halogenation with [RNH3+] [NO3-]/HX and [BMIM(SO3H)][NO3)x(X)y] (X = Br, Cl) as multifunctional ionic liquids
Novel multifunctional ionic liquids (ILs) are generated by addition of HBr or HCl to alkylammonium nitrates ([RNH3+] [NO 3-]) and to 3-methyl-1-(butyl-4-sulfonyl)imidazolium nitrate ([BMIM(SO3H)][NO3]). The resulting [RNH 3+] [NO3-]/HX and mono (3-methyl-1-(butyl-4-sulfonyl)imidazolium) monohalogenide mononitrate ([BMIM(SO3H)][NO3)x(X)y] (X = Br, Cl)) systems act as solvent and promoter for aerobic oxidative halogenation of arenes under mild conditions in high yields that can be repeated over several cycles.
Prebil, Rok,Laali, Kenneth K.,Stavber, Stojan
supporting information
p. 2108 - 2111
(2013/06/05)

An efficient chlorination of aromatic compounds using a catalytic amount of iodobenzene
An efficient method was developed for chlorination of aromatic compounds with electron-donating groups using iodobenzene as the catalyst and m-chloroperbenzoic acid as the terminal oxidant in the presence of 4-methylbenzenesulfonic acid in THF at room temperature for 24 h, and a series of the monochlorinated compounds was obtained in good yields. In this protocol, the catalyst iodobenzene was first oxidized into the hypervalent iodine intermediate, which then treated with lithium chloride and finally reacted with aromatic compounds to form the chlorinated compounds.
Li, Ting-Ting,Xu, Cui,Xiang, Chang-Bin,Yan, Jie
p. 535 - 538
(2013/07/27)

Aromatic substitution in ball mills: Formation of aryl chlorides and bromides using potassium peroxomonosulfate and NaX
Aryl chlorides and bromides are formed from arenes in a ball mill using KHSO5 and NaX (X = Cl, Br) as oxidant and halogen source, respectively. Investigation of the reaction parameters identified operating frequency, milling time, and the number of milling balls as the main influencing variables, as these determine the amount of energy provided to the reaction system. Assessment of liquid-assisted grinding conditions revealed, that the addition of solvents has no advantageous effect in this special case. Preferably activated arenes are halogenated, whereby bromination afforded higher product yields than chlorination. Most often reactions are regio- and chemoselective, since p-substitution was preferred and concurring side-chain oxidation of alkylated arenes by KHSO5 was not observed. The Royal Society of Chemistry.
Schmidt, Robert,Stolle, Achim,Ondruschka, Bernd
p. 1673 - 1679
(2013/02/22)

Nucleophilic substitution of hydrogen in naphthalene by chloride (Cl -) in ionic liquids
Nucleophilic aromatic substitution of hydrogen in non-activated aromatic ring, a very rare phenomenon in organic chemistry, is found in ionic liquids containing Cl- as anion under mild reaction conditions. The reaction may be carried out by the addition of the halogen-bonding adduct (Br 2Cl-) as nucleophile to aromatic ring carbon atom, leading to the formation of the nucleophilic substitution product.
Shi, Shen Yi,Kong, Ai Guo,Zhao, Xin Hua,Ding, Han Ming,Yang, Fan,Shan, Yong Kui
experimental part
p. 147 - 150
(2012/01/03)

Novel C-H functionalization of arenes: Palladium-catalyzed synthesis of diaryl sulfides
A novel protocol for the direct arylthiolation of electron-rich arenes is described. Applying arylsulfonyl cyanides in the presence of catalytic amounts of Pd allows for a straightforward synthesis of diaryl sulfides.
Anbarasan, Pazhamalai,Neumann, Helfried,Beller, Matthias
supporting information; experimental part
p. 3233 - 3235
(2011/05/05)

Bis- N -heterocyclic carbene palladium(IV) tetrachloride complexes: Synthesis, reactivity, and mechanisms of direct chlorinations and oxidations of organic substrates
This Article describes the preparation and isolation of novel octahedral CH2-bridged bis-(N-heterocyclic carbene)palladium(IV) tetrachlorides of the general formula LPdIVCl4 [L = (NHC)CH 2(NHC)] from LPdIICl2 and Cl2. In intermolecular, nonchelation-controlled transformations LPdIVCl 4 reacted with alkenes and alkynes to 1,2-dichlorination adducts. Aromatic, benzylic, and aliphatic C-H bonds were converted into C-Cl bonds. Detailed mechanistic investigations in the dichlorinations of alkenes were conducted on the 18VE PdIV complex. Positive solvent effects as well as kinetic measurements probing the impact of cyclohexene and chloride concentrations on the rate of alkene chlorination support a PdIV-Cl ionization in the first step. Product stereochemistry and product distributions from various alkenes also support Cl+-transfer from the pentacoordinated PdIV-intermediate LPdIVCl 3+ to olefins. 1-Hexene/3-hexene competition experiments rule out both the formation of π-complexes along the reaction coordinate as well as in situ generated Cl2 from a reductive elimination process. Instead, a ligand-mediated direct Cl+-transfer from LPd IVCl3+ to the π-system is likely to occur. Similarly, C-H bond chlorinations proceed via an electrophilic process with in situ formed LPdIVCl3+. The presence of a large excess of added Cl- slows cyclohexene chlorination while the presence of stoichiometric amounts of chloride accelerates both PdIV-Cl ionization and Cl+-transfer from LPdIVCl3 +. 1H NMR titrations, T1 relaxation time measurements, binding isotherms, and Job plot analysis point to the formation of a trifurcated Cl-...H-C bond in the NHC-ligand periphery as a supramolecular cause for the accelerated chemical events involving the metal center.
McCall, A. Scott,Wang, Hongwang,Desper, John M.,Kraft, Stefan
scheme or table
p. 1832 - 1848
(2011/04/15)

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)

Chlorination of aromatics with trichloroisocyanuric acid (TCICA) in bronsted-acidic imidazolium ionic liquid [BMIM(SO3H)][OTf]: An economical, green protocol for the synthesis of chloroarenes
A survey study on electrophilic chlorination of aromatics with trichloroisocyanuric acid (TCICA) in Bronsted-acidic imidazolium ionic liquid [BMIM(SO3H)][OTf] is reported. The reactions are performed under very mild conditions (at ～50°C) and give good to excellent yields, depending on the substrates. Chemoselectivity for mono- v. dichlorination can be tuned by changing the arene-to-TCICA ratio and the reaction time. The survey study and competitive experiments suggest that triprotonated/protosolvated TCICA is a selective/moderately reactive transfer-chlorination electrophile. Density functional theory was used as guide to obtain further insight into the nature of the chlorination electrophile and the transfer-chlorination step. CSIRO 2007.
Hubbard, Abigail,Okazaki, Takao,Laali, Kenneth K.
p. 923 - 927
(2008/03/17)

Catalytic process for regiospecific chlorination of alkanes, alkenes and arenes
The present invention provides a process for regiospecific chlorination of an aromatic or aliphatic compound with a chlorine source comprising a metal chloride and other than Cl2and SO2Cl2in presence of hypervalent iodine catalyst and in acidic medium.
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Page column 6

(2008/06/13)

Oxidative halogenation of aromatic compounds with metal halides and sodium bismuthate
A new mild and efficient method for aromatic halogenation with a wide variety of halides in the presence of sodium bismuthate NaBO3 in AcOH is reported. Metal halides of groups Ia, IIa, IIIa, IVa, Va, and the first row of transition elements are suitable for this method.
Muathen, Hussni A.
p. 164 - 168
(2007/10/03)

Electrophilic aromatic chlorination and haloperoxidation of chloride catalyzed by polyfluorinated alcohols: A new manifestation of template catalysis
We have demonstrated that a polyfluorinated alcohol, 2,2,2-trifluoroethanol, solvent enables haloperoxidase type activity and the oxychlorination of arenes (benzene and its alkylated derivatives) without a metal catalyst. The polyfluorinated alcohol has a dual function; it catalyzes electrophilic chlorination of less reactive arenes by several orders of magnitude and oxidation of chloride at lower H+ concentrations. DFT calculations show that a complementary charge template in the transition state explains the catalysis of the electrophilic chlorination. Copyright
Ben-Daniel, Revital,De Visser, Samuel P.,Shaik, Sason,Neumann, Ronny
p. 12116 - 12117
(2007/10/03)

Chlorination of aromatic compounds with chlorous acid under non-aqueous conditions
The non-aqueous solution of chlorous acid is a versatile chlorinating agent for aromatic compounds, e.g. alkylbenzenes, anisoles, and acetanililides. It is also an effective chlorine-substitute for the conversion of aryl bromides into aryl chlorides under mild conditions. The stoichiometry of the chlorination reaction is ArH+3HOClO→ArCl+2ClO2+2H2O, and the mode of dissociation of chlorous acid in dichloromethanc is 3HOClO→HOCl+2ClO2+H2O.
Muathen, Hussni A.
p. 1493 - 1497
(2007/10/03)

Liquid-Phase Decarboxylation of Aromatic Haloformates: A New Access to Chloro- and Fluoroaromatics
The treatment of phenyl chloroformates 1 with a Lewis acid in the liquid phase resulted in decarboxylation to the corresponding chloroaromatics 2. Fluoroaromatic compounds were synthesized from phenylchloroformates 1 through a sequential fluorination/decarboxylation in the liquid phase by treatment with excess anhydrous hydrogen fluoride under mild conditions. In all cases, yields were increased by performing the reaction in 1,2,4-trichlorobenzene, which is inert to Friedel-Crafts reactions.
Lui, Norbert,Marhold, Albrecht,Rock, Michael H.
p. 2493 - 2496
(2007/10/03)

Selective aromatic chlorination of activated arenes with sodium chlorite, (salen)manganese(III) complex, and alumina in dichloromethane
The reaction of alkyl phenyl ethers with sodium chlorite in dichloromethane in the presence of a (salen)manganese(III) complex and alumina preloaded with a small amount of water afforded monochlorination products with unusually high para selectivities under mild conditions. The NaClO2-based biphasic system can also be successfully used for the regioselective monochlorination of substituted anisoles and polymethoxybenzenes.
Hirano,Yakabe,Monobe,Morimoto
p. 1905 - 1912
(2007/10/03)

Mild chlorination of aromatic compounds with tin(IV) chloride and lead tetraacetate
SnCl4/Pb(OAc)4 acts as a safe source of Cl2 for the chlorination of aromatic compounds. A variety of aromatic compounds are effectively chlorinated with SnCl4/Pb(OAc)4 under mild conditions. The mixture is a selective chlorinating agent, particularly with polyalkylbenzenes, polycyclic aromatic compounds and anisoles.
Muathen, Hussni A.
p. 8863 - 8866
(2007/10/03)

Peroxide Salts as Reagents in Oxidative Halogenation of Aromatic Compounds
Chloromesitylene, chloro-p-xylene, and 1-bromonaphthalene are formed in 78, 79, and 86percent yield, respectively, under the action of the halogenating system hydrogen peroxide-hydrohalic acid-AcOH.The following aryl halides are also formed in high yields in this halogenating system: 2-bromothiophene (89 - 92percent) upon bromonation of thiophene; chlorobenzene (77 - 79percent) and iodobenzene (79 - 81percent) upon chlorination and iodination of benzene.
Rudakova, N. I.,Erykalov, Yu. G.,Zharikova, S. M.,Dmitrieva, E. V.,Mataradze, M. S.
p. 271 - 272
(2007/10/03)

Process for the preparation of halogenated aromatic compounds
Halogenated aromatic compounds are prepared by passing esters of halogenoformic acid at temperatures in the range 150° to 600° C. and pressures from 0.1 to 3 bar over a catalyst containing chromium, magnesium, iron, silicon and/or aluminium, wherein if Al2 O3 catalysts are used these have been activated with hydrogen halide.
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(2008/06/13)

Isolation, structure, and reactivity of a novel chloro-arenium cation for electrophilic (transfer) chlorinations
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Rathore,Loyd,Kochi
p. 8414 - 8415
(2007/10/02)

Ring Halogenations of Polyalkylbenzenes by Ionic Halides and Koser's Reagent
Ring chlorinations of polyalkylbenzenes such as mesitylene have been carried out at room temperature with LiCl or NaCl and stoichiometric amounts of Koser's reagent.Solvent range from water to methylene chloride.The procedures were extended to bromination and iodination.
Bovonsombat, Pakorn,Djuardi, Elsa,Nelis, Edward Mc
p. 2841 - 2844
(2007/10/02)

Biphasic Electrophilic Halogenation of Activated Aromatics and Heteroaromatics with N-Halosuccinimides Catalyzed by Perchloric Acid
Catalytic amounts of 70percent perchloric acid (0.1 - 10, mostly 0.1 - 1, mol percent, based on substrate) initiate the regioselective halogenation of activated aromatics and heteroaromatics with N-halosuccinimide (NXS, X = Cl or Br) in two-phase solid-liquid systems (NXS/hexane or NXS/CCl4) at room temperature to give ring-halogenated products in high yields.For example, thiophene is transformed to 2-halo or 2,5-dihalo derivatives (yield 82-98percent) using 1 or 2 equiv of NXS, respectively.Unsymmetrical 2,5-dihalothiophenes are obtained in 70-82percent yield by reacting 2-halothiophenes with an appropriate NXS.The reaction of 3-bromothiophene with NBS affords 2,3-dibromothiophene in 93-99percent yield. 1,3-Dimethoxybenzene and 2,3-dimethylanisole are halogenated regiospecifically at the 4-position to give the corresponding products in 81-94percent yield.
Goldberg, Yuri,Alper, Howard
p. 3072 - 3075
(2007/10/02)

Ring halogenations of polyalkylbenzenes with N-halosuccinimide and acidic catalysts
1-Bromo-2,5-pyrrolidinedione (NBS) and 1-chloro-2,5-pyrrolidinedione (NCS) with catalytic quantities of p-toluenesulfonic acid have been used for ring halogenations of polyalkylbenzenes. [Hydroxy(tosyloxy)iodo]benzene was effective as a catalyst with NBS but not NCS. Competition experiments with 1-iodo-2,5-pyrrolidinedione (NIS) were run to indicate selectivities in substrates, halogen sources and catalysts. With this information a mixed halogenated compound, 2-bromo-4-iodo-1,3,5-trimethylbenzene was prepared in high yield.
Bovonsombat,McNelis
p. 237 - 241
(2007/10/02)

Reaction of Dichlorotriphenylphosphorane with Bis(trimethylsilyl) Peroxide. A new Method for the Formation of Electrophilic Chlorine Source.
Reactions of dichlorotriphenylphosphorane with bis(trimethylsilyl) peroxide in the presence of some organic compounds have been found to give chlorinated products.Aromatic hydrocarbons bearing electron-donating substituents give the corresponding monochloroarenes, while an enol silyl ether is converted into α-chloro-ketone.The mechanism is briefly discussed.
Shibata, Kazusato,Itoh, Yukinori,Tokitoh, Norihiro,Okazaki, Renji,Inamoto, Naoki
p. 3749 - 3751
(2007/10/02)

Optical Rotation of Quaterphenyl Derivatives
Quatermesityl (2) has been resolved by chromatography into pure enantiomers; (S)-(+)-2 shows D = +108 as expected. (S)-(+)-3,3'-Diphenylbimesityl (9) has been prepared enantiospecifically and shows D = +106.Chromatographic reso
Fischer, Erika,Hess, Heinrich,Lorenz, Thomas,Musso, Hans,Rossnagel, Ingrid
p. 783 - 789
(2007/10/02)

Halogenation Using Quaternary Ammonium Polyhalides. XIX. Aromatic Chlorination of Arenes with Benzyltrimethylammonium Tetrachloroiodate
The reaction of arenes with a calculated amount of benzyltrimethylammonium tetrachloroiodate in acetic acid at room temperature or at 70 deg C gave nuclear chloro-substituted arenes in fairly good yields.
Kajigaeshi, Shoji,Ueda, Yasuhiro,Fujisaki, Shizuo,Kakinami, Takaaki
p. 2096 - 2098
(2007/10/02)

Highly Selective Aromatic Chlorination. Part 4. The Chlorination of Aromatic Hydrocarbons with N-Chloroamines in Acidic Solution
Benzene, toluene, some polymethylbenzenes, and naphthalene have been treated with N-chlorotrialkylammonium salts and N-chlorodialkylamines in trifluoroacetic acid at room temperature.With benzene, toluene, and 1,3,5-trimethylbenzene the major products arise from aromatic chlorination whereas with the other polymethylbenzenes side-chain reactions predominate.By controlling the acidity of the reaction and the nature of the N-chloroamine, the chlorination of toluene can be made to give preferentially 2- or 4-chlorination.However, the selectivities are not as great as reported previously with electron-rich aromatic compounds with a ?-donor substituent.The products from the reaction of naphthalene are very dependent on the structure of the N-chlorinated amine.The bulky N-chlorotrialkylammonium salts selectively chlorinate the 1-position, but in low yield, whereas the less hindered N-chloropiperidine gives good yields of 1-(1-piperidino)-naphthalene.The results from these studies are discussed in terms of arenium-ion and electron-transfer mechanisms.
Smith, John R. Lindsay,McKeer, Linda C.,Taylor, Jonathan M.
p. 1537 - 1544
(2007/10/02)

ON THE ABSOLUTE REACTIVITY OF ARYL CATIONS: SELECTIVITY TOWARD HALIDE IONS AS A FUNCTION OF VISCOSITY
The selectivities toward bromide and chloride ions observed in the dediazoniation of three arenediazonium salts are found to be independent of viscosity.It is inferred that the capture of aryl cations by these halide ions is diffusion controlled.
Lorand, John P.
p. 7337 - 7340
(2007/10/02)

Selective Nuclear Halogenation of Polymethylbenzenes with Alumina-Supported Copper(II) Halides
The halogenation of polymethylbenzenes with alumina-supported copper(II) halides under heterogeneous conditions in nonpolar solvents gave nuclear-halogenated compounds selectively in high yields; no side-chain-halogenated compounds were formed.
Kodomari, Mitsuo,Satoh, Hiroaki,Yoshitomi, Suehiko
p. 4149 - 4150
(2015/06/25)

OXIDATIVE CHLORINATION OF AROMATIC COMPOUNDS IN THE PRESENCE OF NITROGEN-CONTAINING OXIDIZING AGENTS
Mixture of the chlorides and nitrates of alkali metals in aqueous trifluoroacetic acid can be used for the selective oxidative chlorination of benzene, halogenobenzenes, toluene, and p-toluic acid with preparative yields.By variation of the water content of the solvent and the nitrate-chloride ratio it is possible to suppress the nitration side reaction.In the presence of oxygen or air alkali-metal nitrites can also be used as oxidizing agents in this process.The chlorinating agent in these systems is molecular chlorine, as confirmed by a comparative study of the reactions of two groups of potential chlorinating agents (nitrosyl chloride and nitryl chloride) under these conditions.The reactions of naphthalene and polymethylbenzenes with nitrosyl chloride in trifluoroacetic acid, leading to the products from chlorination and dehydrooligomerization of the aromatic substrates, were also studied.
Makhon'kov, D. I.,Cheprakov, A. V.,Rodkin, M. A.,Beletskaya, I. P.
p. 211 - 217
(2007/10/02)

Chlorobenzenedicarboxaldehyde and Chlorobenzenetricarboxaldehyde from Cyclohexenones under Vilsmeier Reaction Conditions
The isomeric cyclohexenone mixture (II+III), (VI+VII) and (X+XI) afford on Vilsmeier reaction the chlorobenzenecarboxaldehydes (IV), (VIII) and (XII), respectively in good yields.Besi
Raju, B.,Rao, G. S. Krishna
p. 177 - 178
(2007/10/02)

THE PREPARATION OF FLUOROARENES BY THE CATALYTIC DECARBOXYLATION OF ARYL FLUOROFORMATES
The catalytic decarboxylation of phenyl fluoroformate to fluorobenzene has been achieved with yields of 70-80percent in a flow system using alumina or alumina-based catalysts.The reaction occurs in short space times (Pd/Al2O3>Rh/Al2O3 ca.Al2O3. 2,4,6-Trimethylphenyl fluoroformate, a new material, was found to decarboxylate similarly to give 1-fluoro-2,4,6-trimethylbenzene, but 4-chlorophenyl fluoroformate was noted to produce only low yields (ca. 10percent) of the corresponding aryl fluoride.
Ashton, David P.,Ryan, Anthony T.,Webster, Brian R.,Wolfindale, Brett A.
p. 263 - 274
(2007/10/02)

Functionalisation of Saturated Hydrocarbons. Part 1. Some Reactions of a Ferrous Chloride-Chloramine-T Complex with Hydrocarbons
The reactions of several hydrocarbons substrates with a ferrous chloride-chloramine-T complex, generated in situ, have been studied.Tosylamination of adamantane and chlorination of mesitylene proceed in good yield while naphthalene gives N,N'-bis(toluene-p-sulphonyl)-1,4-naphthoquinone di-imine.A variety of olefinic substrates undergo both cis- and trans-addition to the double bond as well as allylic functionalisation.
Barton, Derek H. R.,Hay-Motherwell, Robyn S.,Motherwell, William B.
p. 445 - 452
(2007/10/02)

PhSeCl AS A CHLORINATING AGENT FOR ACTIVATED BENZENE DERIVATIVES
Regiospecific chlorination of some aromatic compounds using benzeneselenyl chloride are reported.
Ayorinde, Folahan O.
p. 2077 - 2078
(2007/10/02)