583-53-9Relevant articles and documents
Oxidative bromination of non-activated aromatic compounds with AlBr3/KNO3 mixture
Rahu, Ida,J?rv, Jaak
, p. 1219 - 1227 (2019/11/13)
Bromination of non-activated aromatic compounds with reaction mixture containing KNO3 and AlBr3 was studied in liquid substrates and in solvent. Aluminium bromide has three different roles in this reaction mixture. First, it is a source of bromide ions, which are essential in oxidative bromination application. Second, it acts as a catalyst, and lastly, it forms acidic environment via its hydrolysis, which is necessary for enhancement of the oxidising properties of nitrate ions. It was shown that when changing the reaction conditions, different side reactions (like nitration or Friedel–Crafts type arylation) can occur. However, it is possible to guide the reaction path and receive the desired outcome by choosing the suitable reaction conditions. In addition, it was shown that there has to be water content in this reaction mixture as the bromine formation rate depends on it, while there exists an optimal volume of water, where bromine formation is the fastest.
"naked" Lithium Cation: Strongly Activated Metal Cations Facilitated by Carborane Anions
Kitazawa, Yu,Takita, Ryo,Yoshida, Kengo,Muranaka, Atsuya,Matsubara, Seijiro,Uchiyama, Masanobu
, p. 1931 - 1935 (2017/02/26)
Experimental and spectroscopic studies revealed unprecedented reactivity of a "naked" lithium cation with very weakly coordinating anions, including carborane anions. The superactivated lithium cation has greatly enhanced Lewis acidic character and mediates various organic reactions such as carbonyl-ene reaction, NBS-bromination of unactivated aromatics, and Friedel-Crafts alkylation, which are not promoted by conventional lithium salts. Chemical robustness of the counteranion also plays an important role in the chemistry of the strongly activated lithium cation.
PROCESS FOR THE PREPARATION OF ORGANIC BROMIDES
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Paragraph 00133, (2017/07/28)
The present invention provides a process for the preparation of organic bromides, by a radical bromodecarboxylation of carboxylic acids with a bromoisocyanurate.
Reactivity of alkali and alkaline earth metal tetrafluorobromates towards aromatic compounds and pyridine
Sobolev, Vasily I.,Filimonov, Victor D.,Ostvald, Roman V.,Radchenko, Vyacheslav B.,Zherin, Ivan I.
, p. 120 - 123 (2016/11/17)
The bromination activity of tetrafluorobromates of alkali and alkali-earth metals increases in the order KBrF4, CsBrF4, RbBrF4and Ba(BrF4)2. The most active tetrafluorobromate—Ba(BrF4)2is able to selectively brominate the deactivated aromatic compounds nitrobenzene and 4-nitrotoluene, but not the activated compounds benzene and toluene. In all cases bromination of methyl groups of methylbenzenes does not occur. Ba(BrF4)2forms the known complex C6H5N·BrF3when reacted with pyridine. Due to dilution by inert BaF2, this pyridine-based complex is air stable and can be considered as safer and more convenient reagent in comparison with the original fluorobromates; it can selectively brominate benzene and toluene in contrast with tetrafluorobromates.
Substd. photoisomerization arom. compd. method
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Paragraph 0068, (2017/01/02)
Isomerizing substituted aromatic compounds (I), comprises carrying out isomerization in the presence of a salt melt, which contains a metal compound (II) and at least one metal compound (III). Isomerizing substituted aromatic compounds of formula (Ar1-R n) (I) or their mixtures, comprises carrying out isomerization in the presence of a salt melt, which contains a metal compound of formula ([M1][X1] m 1) (II) and at least one metal compound of formula ([M2][X2] m 2) (III). Ar1 : n-valent aryl radical; R : halo, alkyl, fluoroalkyl, aryl, alkyl-aryl or amino; M1 : Al, Ga, In, Cu, Fe, Co or Ni; X1, X2 : halo, preferably Cl or Br; M2, m2 : alkaline earth metal or alkali metal, where M2 is preferably Li, Na, or K; m1 : Al, Ga, In, Fe(III), Co, Ni or Cu(II); and n : >= 2, preferably 2.
Tribromoisocyanuric acid in trifluoroacetic acid: An efficient system for smooth brominating of moderately deactivated arenes
De Almeida, Leonardo S.,De Mattos, Marcioc. S.,Esteves, Pierre M.
, p. 603 - 606 (2013/04/10)
Moderately deactivated arenes are efficiently brominated by the reaction with tribromoisocyanuric acid (0.34 mol equiv) in trifluoroacetic acid at room temperature in 48-85% isolated yield. This medium avoids the polybromination of the substrate, observed in the same reaction performed in 98% H 2SO4. Georg Thieme Verlag Stuttgart · New York.
Bromination of aromatic compounds using an Fe2O 3/zeolite catalyst
Nishina, Yuta,Takami, Keishi
supporting information, p. 2380 - 2383 (2013/02/21)
The catalytic bromination of non-activated aromatic compounds has been achieved using an Fe2O3/zeolite catalyst system. FeBr 3 was identified as the catalytic species, formed in situ from HBr and Fe2O3. The catalyst was easy-to-handle and cost effective and could also be recycled. The reaction system was also amenable to the one-pot sequential bromination/C-C bond formation of benzene.
Efficient and complementary methods offering access to synthetically valuable 1,2-dibromobenzenes
Diemer, Vincent,Leroux, Frederic R.,Colobert, Fracoise
experimental part, p. 327 - 340 (2011/02/26)
1,2-Dibromobenzenes are highly valuable precursors for various organic transformations, in particular, reactions based on the intermediate formation of benzynes. This report describes short sequences for the synthesis of various derivatives based on regioselective bromination, ortho-metalation, and halogen/metal permutations. 1,2-Dibromo-3-iodobenzene (2f), 1,2-dibromo-4- iodobenzene (4c), and 2,3-dibromo-1,4-diiodobenzene (5e) act as intermediates in these syntheses. Bromo-iodoarenes have been synthesized by short and regioselective bromination or iodination sequences that combine ortho-metalation, halo-desilylation, diazotation, or bromination reactions of anilines. These polyhalo derivatives were then used as key intermediates to access a wide range of functionalized 1,2-dibromobenzenes by chemoselective organometallic reactions. Copyright
Synthesis of uniformly 13C-labeled polycyclic aromatic hydrocarbons
Zhang, Zhenfa,Sangaiah, Ramiah,Gold, Avram,Ball, Louise M.
, p. 5431 - 5435 (2011/09/14)
Convergent synthetic pathways were devised for efficient synthesis of a series of uniformly 13C labeled polycyclic aromatic hydrocarbons de novo from U-13C-benzene and other simple commercially-available 13C-starting compounds. All target products were obtained in excellent yields, including the alternant PAH U-13C-naphthalene, U-13C-phenanthrene, U-13C-anthracene, U- 13C-benz[a]anthracene, U-13C-pyrene and the nonalternant PAH U-13C-fluoranthene.
Thallium(III) oxide as an oxidative reagent in organic chemistry
Gun'kin
scheme or table, p. 451 - 454 (2010/08/04)
Oxidative properties of thallium(III) oxide in various organic reactions were studied. Oxidative bromination of organic compounds in Tl2O 3-KBr-trifluoroacetic acid system was carried out. New synthetic method for preparation of diphenylthallium salts from phenylhydrazine and thallium(III) oxide was developed.
