- Rhodium(III)-Catalyzed Selective C-H Acetoxylation and Hydroxylation Reactions
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An efficient Cp?Rh(III)-catalyzed, chelation-assisted C(sp2)-H acetoxylation and hydroxylation reaction has been developed for the first time. The reaction proceeds under mild conditions and allows for selective preparation of C-H acetoxylation
- Wu, Yunxiang,Zhou, Bing
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supporting information
p. 3532 - 3535
(2017/07/17)
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- Palladium catalyzed Csp2-H activation for direct aryl hydroxylation: The unprecedented role of 1,4-dioxane as a source of hydroxyl radicals
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A novel strategy for direct aryl hydroxylation via Pd-catalysed Csp2-H activation through an unprecedented hydroxyl radical transfer from 1,4-dioxane, used as a solvent, is reported with bio relevant and sterically hindered heterocycles and various acyclic functionalities as versatile directing groups.
- Seth, Kapileswar,Nautiyal, Manesh,Purohit, Priyank,Parikh, Naisargee,Chakraborti, Asit K.
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supporting information
p. 191 - 194
(2015/01/09)
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- Intensely fluorescent azobenzenes: Synthesis, crystal structures, effects of substituents, and application to fluorescent vital stain
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2-[Bis(pentafluorophenyl)boryl]azobenzenes bearing hydrogen, methoxy, dimethylamino, trifluoromethyl, fluoro, n-butyl, and tert-butyldimethylsiloxy groups at the 4′-position or methoxy and bromo groups at the 4position have been synthesized. The 4bromo group of the 2-boryl-4-bromoazobenzene derivative was converted to phenyl and diphenylamino groups by palladium-catalyzed reactions. The absorption and fluorescence properties have been investigated using UV/Vis and fluorescence spectroscopy. The 2-borylazobenzenes emitted an intense green, yellow, and orange fluorescence, in marked contrast to the usual azobenzene fluorescence. The 4′-siloxy derivative showed the highest fluorescence quantum yield (0.90) among those reported for azobenzenes to date. The correlation between the substituent and the fluorescence properties was elucidated by studying the effect of the substituent on the relaxation process and from DFT and TD-DFT calculations. An electron-donating group at the 4′-position was found to be important for an intense emission. Application of fluorescent azobenzenes as a fluorescent vital stain for the visualization of living tissues was also investigated by microinjection into Xenopus embryos, suggesting these compounds are nontoxic towards embryos.
- Yoshino, Junro,Furuta, Akiko,Kambe, Tetsuya,Itoi, Hiroaki,Kano, Naokazu,Kawashima, Takayuki,Ito, Yuzuru,Asashima, Makoto
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supporting information; experimental part
p. 5026 - 5035
(2010/09/03)
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- Photochemical Behavior of 1,3-Diaryltriazene 1-Oxides
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Photolysis of the 1,3-dipolar unsymmetrical 1,3-triazene 1-oxides in aromatic and nonaromatic solvents led to their decomposition. 2-Hydroxyazobenzene, mono- and disubstituted biaryls were produced.
- El-Din, Ahmed Moukhtar Nour,Mohamed, Shaaban Kamel,Doepp, Dietrich
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p. 131 - 135
(2007/10/03)
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- SYNTHESIS OF AZOXYBENZENE-SbCl5 COMPLEXES AND THEIR SELECTIVE ORTHO-WALLACH REARRANGEMENT
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When an equimolar solution of various azoxybenzenes and SbCl5 in carbon tetrachloride were mixed, a 1:1 complex immediately deposited as orange crystals in high yield.The thermal reaction of these complexes in inert solvents gives o-hydroxy-azobenzene selectively.On the contrary, other Lewis acids, such as TiCl4, AlCl3, FeCl3 and ZnBr2 failed to give an isolatable complex with azoxybenzene, and their direct thermal reaction with azoxybenzene resulted in deoxygenation to yield azobenzene as a main product.
- Yamamoto, Jiro,Nishigaki, Yukihiro,Umezu, Masahiro,Matsuura, Teruo
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p. 3177 - 3180
(2007/10/02)
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