- Structural and energetic effect of the intramolecular hydrogen bonding in 4,6-dihaloresorcinols: ab initio calculation, vibrational spectroscopy, and molecular docking studies
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The intramolecular hydrogen bonding in the series of 4,6-dihaloresorcinols (with halogen atoms being F, Cl, Br, or I) is believed to play a noticeable role in determining the structural and electronic aspects. All theoretical levels employed in this work
- Popoola, Saheed A.,Onawole, Abdulmujeeb T.,Ullah, Nisar,Al-Saadi, Abdulaziz A.
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- Method for photocatalytic synthesis of polybrominated phenol compound in water phase
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The invention discloses a method for photocatalytic synthesis of a polybrominated phenol compound in a water phase, comprising the following steps: adding a catalytic amount of a radical initiator, aphenol derivative and low-toxic and cheap bromide salt and water into a reaction vessel, reacting at room temperature at 5 W power in a photocatalytic reactor for a certain period, extracting with ethyl acetate and then re-crystallizing to obtain a polybrominated phenol compound. The above radical initiator is eosin, azobisisobutanol, sodium persulfate, ammonium persulfate or potassium persulfate.The free radical initiator and the bromine salt are cheap and easily available, and the method is an ideal synthesis method of the polybrominated phenol compound. According to the method, low-toxicity bromine salt instead of liquid bromine is used to carry out a bromination reaction, unstable and explosive hydrogen peroxide is replaced with the cheap and easily-available free radical initiator, and an emerging photocatalytic method is used. The polybrominated phenol compound can be obtained in a high yield by only using a 5W power lamp for the reaction, the reaction selectivity is high, by-products are less, and the post-treatment is simple.
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Paragraph 0012; 0027
(2019/08/30)
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- Synthesis of phenylethynylbenzenes
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A method of: reacting a dihydroxybenzene with bromine to form a bromodihydroxybenzene; reacting the bromodihydroxybenzene with trifluoromethanesulfonyl chloride or trifluoromethanesulfonic anhydride to form a bromotrifluoromethanesulfonatobenzene; and reacting the bromotrifluoromethanesulfonatobenzene with phenylacetylene to form a phenylethynylbenzene.
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Page/Page column 9
(2018/06/08)
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- AROMATIC POLYACETALS AND ARTICLES COMPRISING THEM
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A polymer includes repeat units having the structure wherein R1, R2, Ar1, Ar2, and Ar3 are defined herein. The polymer can be prepared by Suzuki polycondensation. The acetal and/or ketal functionality
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Paragraph 0049; 0050
(2015/02/18)
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- Bromination of aromatic compounds using ammonium bromide and oxone
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A simple, efficient and mild method for the selective bromination of activated aromatic compounds using ammonium bromide as the source of bromine and Oxone as the oxidant in methanol or water as solvent is reported. The reaction proceeds at ambient temperature in yields ranging from moderate to excellent without a catalyst. Georg Thieme Verlag Stuttgart.
- Arunkumar, MacHarla,Rohitha, Chozhiyath Nappunni,Kulkarni, Shivanand Janardhan,Narender, Nama
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experimental part
p. 1629 - 1632
(2010/06/20)
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- Vanadium-catalyzed oxidative bromination promoted by Br?nsted acid or Lewis acid
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The oxidative bromination of arenes was induced by a vanadium catalyst in the presence of a bromide salt and a Br?nsted acid or a Lewis acid under molecular oxygen, which provides an eco-friendly bromination method as compared with a conventional bromination one with bromine. This catalytic reaction could be applied to the bromination of alkenes and alkynes to give the corresponding vic-bromides. Use of aluminum halide as a Lewis acid in place of a Br?nsted acid was demonstrated to provide a more practical protocol for the oxidative bromination. From ketones, α-bromination products were obtained. AlBr3 was found to serve as both a bromide source and a Lewis acid to induce the bromination smoothly. 51V NMR experiment showed that this catalytic bromination is likely to depend on the redox cycle of a vanadium catalyst under molecular oxygen.
- Kikushima, Kotaro,Moriuchi, Toshiyuki,Hirao, Toshikazu
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experimental part
p. 6906 - 6911
(2010/09/18)
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- Oxidative bromination reaction using vanadium catalyst and aluminum halide under molecular oxygen
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The vanadium-catalyzed oxidative bromination reaction of arenes, alkenes, and alkynes was performed in the presence of AlBr3 to provide an alternative method for conventional bromination using hazardous bromine. The catalytic cycle is formed under molecular oxygen, which is more advantageous to vanadium bromoperoxidase (VBrPO) requiring hydrogen peroxide as a terminal oxidant.
- Kikushima, Kotaro,Moriuchi, Toshiyuki,Hirao, Toshikazu
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supporting information; experimental part
p. 340 - 342
(2010/03/04)
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- Total synthesis of psoralidin, an anticancer natural product
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A base-catalyzed condensation of phenyl acetate with acid chloride, followed by intramolecular cyclization and microwave-assisted cross-metathesis reaction, leads to the first total synthesis of psoralidin, a natural product with a broad range of biological activities, in a highly convergent and regioselective manner.
- Pahari, Pallab,Rohr, Juergen
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supporting information; experimental part
p. 2750 - 2754
(2009/08/15)
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- Selective halogenation of aromatics by dimethyldioxirane and halogen ions
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The oxidation of halogen anions by dimethyldioxirane (DMD) produced reactive species which led, in acidic media, to the halogenation of activated aromatic rings. The reaction can be efficiently controlled to obtain selective and mixed halogenated species.
- Bovicelli,Mincione,Antonioletti,Bernini,Colombari
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p. 2955 - 2963
(2007/10/03)
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- Investigations into the bromination of substituted phenols using diethyl bromomalonate and diethyl dibromomalonate
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Substituted 4-bromophenols can be synthesised efficiently by heating the corresponding phenol in either neat diethyl bromomalonate or diethyl dibromomalonate. We discuss the regioselectivity of such reactions and comment on the scope and limitation of this procedure.
- Coumbarides,Dingjan,Eames,Weerasooriya
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p. 179 - 180
(2007/10/03)
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- Binding features of molecular clips derived from diphenylglycoluril
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The structure and binding properties of a series of receptor molecules based on the building block diphenylglycoluril are described. These receptors bind dihydroxy-substituted aromatic guests in chloroform solution by means of hydrogen bonding and π-π stacking interactions. IR difference spectroscopy shows that the hydrogen bonds are formed between the OH groups of the guest molecule and the π-electrons of the urea carbonyl groups present in the receptor. The structure of the complexes was further investigated by comparing the complexation-induced shifts in the 1H NMR spectra with the calculated shifts for a number of geometries of the host-guest complexes. These data demonstrate that the guest molecules are clamped within the cavity of the receptor.
- Sijbesma,Kentgens,Lutz,Van Der Maas,Nolte
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p. 8999 - 9005
(2007/10/02)
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- Halogenation Using Quaternary Ammonium Polyhalides. IV. Selective Bromination of Phenols by Use of Tetraalkylammonium Tribromides
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Reaction of phenols with calculated amounts of benzyltrimethylammonium tribromide or tetrabutylammonium tribromide in dichloromethane-methanol for 0.5-1 h under mild conditions gave, selectively, the objective mono-, di-, or tribromophenols in good yields.
- Kajigaeshi, Shoji,Kakinami, Takaaki,Okamoto, Tsuyoshi,Nakamura, Hiroko,Fujikawa, Masahiro
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p. 4187 - 4189
(2007/10/02)
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