716-53-0Relevant articles and documents
Solvent-dependent quenching of the lowest excited singlet state of 9,10-dichloroanthracene by ground-state 2,5-dimethylhexa-2,4-diene yielding 9-chloroanthracene in acetonitrile or the [4+2]adduct in n-Heptane
Nakayama, Toshihiro,Amijima, Yutaka,Miki, Sadao,Hamanoue, Kumao
, p. 223 - 224 (1997)
In acetonitrile, an exciplex formed between the lowest excited singlet state (1DCA*) of 9,10-dichloroanthracene (DCA) and ground-state 2,5-dimethylhexa-2,4-diene (DMHD) generates the DCA radical anion as an intermediate for dechlorination of DCA yielding 9-chloroanthracene. In n-heptane, however, quenching of 1DCA* by DMHD forms no exciplex and a dibenzobicyclo[2.2.2]octadiene-type compound (the [4+2] adduct) is obtained as the final product.
The Reaction Involving One Electron Transfer in Key Step. NO2-Catalyzed Halogenation of Polycyclic Aromatic Compounds with Metal Halides
Sugiyama, Takashi
, p. 1504 - 1508 (1982)
In the co-existence of catalytic amount of nitrogen dioxide and oxygen, aluminum halide, titanium(IV) halide, and some other metal halides have been found to be highly selective and regiospecific halogenating agents for polycyclic aromatic compounds, including anthracene, pyrene, benzanthracene, chrysene, phenanthrene, naphthalene, triphenylene, fluoranthene, benzothiophene, and dibenzothiophene.
Efficient halogenation synthesis method of aryl halide
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Paragraph 0151-0154, (2021/03/31)
The invention discloses an efficient halogenation synthesis method of aryl halide. The method comprises the following step: in the presence of a catalyst (sulfoxide or oxynitride), a halogenation reagent and a solvent, carrying out a halogenation reaction on an aromatic ring compound to obtain the aryl halide. According to the present invention, in the presence of a catalyst (sulfoxide or nitrogenoxide), a halogenation reagent and a solvent, the aromatic ring is subjected to an efficient halogenation reaction, such that the very useful aryl halide can be obtained with high activity and high selectivity; and by adopting the method disclosed by the invention, aryl halides can be efficiently synthesized, and the method has a wide application prospect in actual production.
In situ Generation of Hypervalent Iodine Reagents for the Electrophilic Chlorination of Arenes
Granados, Albert,Jia, Zhiyu,del Olmo, Marc,Vallribera, Adelina
, p. 2812 - 2818 (2019/04/08)
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.
Selective Halogenation Using an Aniline Catalyst
Samanta, Ramesh C.,Yamamoto, Hisashi
supporting information, p. 11976 - 11979 (2015/08/18)
Electrophilic halogenation is used to produce a wide variety of halogenated compounds. Previously reported methods have been developed mainly using a reagent-based approach. Unfortunately, a suitable "catalytic" process for halogen transfer reactions has yet to be achieved. In this study, arylamines have been found to generate an N-halo arylamine intermediate, which acts as a highly reactive but selective catalytic electrophilic halogen source. A wide variety of heteroaromatic and aromatic compounds are halogenated using commercially available N-halosuccinimides, for example, NCS, NBS, and NIS, with good to excellent yields and with very high selectivity. In the case of unactivated double bonds, allylic chlorides are obtained under chlorination conditions, whereas bromocyclization occurs for polyolefin. The reactivity of the catalyst can be tuned by varying the electronic properties of the arene moiety of catalyst.
Features of the Diels-Alder reaction between 9,10-diphenylanthracene and 4-phenyl-1,2,4-triazoline-3,5-dione
Kiselev,Kornilov,Kashaeva,Potapova,Krivolapov,Litvinov,Konovalov
, p. 2073 - 2080 (2015/02/19)
The Diels-Alder reaction between substituted anthracenes 1a-1j and 4-phenyl-1,2,4-triazoline-3,5 (2) is studied. In all cases except one, the reaction proceeds on the most active 9,10-atoms of substituted anthracenes. The orthogonality of the two phenyl groups at the 9,10-position of diene 1a is found to shield 9,10-reactive centers. No dienophiles with C=C bonds are shown to participate in the Diels-Alder reaction with 1a; however, the reaction 1a + 2 proceeds with the very active dienophile 2,4-phenyl-1,2,4-triazoline-3,5-dione. It is shown that attachment occurs on the less active but sterically accessible 1,4-reactive center of diene 1a. The structure of adduct 3a is proved by 1H and 13C NMR spectroscopy and X-ray diffraction analysis. The following parameters are obtained for reaction 1a + 2 ? 3a in toluene at 25°C: Keq = 2120 M-1, ΔHf≠ = 58.6 kJ/mol, ΔSf≠ = -97 J/(mol K), ΔVf≠ = -17.2 cm3/mol, ΔHb ≠ = 108.8 kJ/mol, ΔSb≠ = 7.3 J/(mol K), ΔVb≠ = -0.8 cm3/mol, ΔHr-n = -50.2 kJ/mol, ΔSr-n = -104.3 J/(mol K), ΔVr-n = -15.6 cm3/mol. It is concluded that the values of equilibrium constants of the reactions 1a-1j + 2 ? 3a-3j vary within 4 × 101-1011 M-1.
Air-stable nickel precatalysts for fast and quantitative cross-coupling of aryl sulfamates with aryl neopentylglycolboronates at room temperature
Jezorek, Ryan L.,Zhang, Na,Leowanawat, Pawaret,Bunner, Matthew H.,Gutsche, Nicholas,Pesti, Aleksander K. R.,Olsen, James T.,Percec, Virgil
supporting information, p. 6326 - 6329 (2015/02/19)
A library containing 10 air-stable NiIIX(Aryl)(PCy3)2 complexes as precatalysts (X = Cl, Br, OTs, OMs, aryl = 1-naphthyl, 2-naphthyl; X = Cl, 1-acenaphthenyl, 1-(2-methoxynaphthyl), 9-phenanthrenyl, 9-anthracyl) was synthesized and demonstrated to quantitatively cross-couple 2-methoxyphenyl dimethylsulfamate with methyl 4-(5,5-dimethyl-1,3,2-dioxaborinane-2-yl)benzoate at 23 °C in dry THF in the presence of K3PO4(H2O)3.2 in less than 60 min. Lower or higher amounts of H2O in K3PO4 and as received THF mediate the same transformation in a maximum three times longer reaction time.
Aromatic substitution in ball mills: Formation of aryl chlorides and bromides using potassium peroxomonosulfate and NaX
Schmidt, Robert,Stolle, Achim,Ondruschka, Bernd
, p. 1673 - 1679 (2013/02/22)
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.
Why can the activation volume of the cycloadduct decomposition in isopolar retro-diels-alder reactions be negative?
Kiselev, Vladimir D.
experimental part, p. 117 - 125 (2011/05/19)
Rate constants of the Diels-Alder cycloaddition reaction of anthracene with tetracyanoethylene, enthalpy of solution of reactants and adduct, enthalpy of the reaction in solution, enthalpy and entropy of activation of the forward and retro-Diels-Alder reactions were determined in 14 solvents. Temperature and pressure effects on the rate of the decomposition of the adduct formed from 9-chloroanthracene and tetracyanoethylene were studied. Since the electrostriction effect can be excluded from the consideration of the isopolar Diels-Alder reaction, negative values of the activation volume in the retro-Diels-Alder reactions can be caused by the different possibilities of penetration of the solvent molecules to large steric branched structures of the transition states and adducts.
Energy and volume activation parameters of the retro-Diels-Alder reaction in different solvents
Kiselev,Kashaeva,Bolotov,Shakirova,Konovalov
scheme or table, p. 21 - 24 (2010/06/12)
The temperature and pressure effects on the decay rate of an adduct obtained from 9-chloroanthracene and tetracyanoethene by a Diels-Alder reaction were studied. The rate constants (298.2 K) and the enthalpies, entropies, and volumes of activation were determined for the retro-Diels-Alder reaction in different solvents. The data obtained confirm a possible decrease in the molar volume of the solvated adduct upon partial bond cleavage on the way to the transition state. The reversal of the sign in front of the activation volume cannot be indicative of a changed reaction mechanism.
