2641-89-6Relevant academic research and scientific papers
Metal-free reduction of unsaturated carbonyls, quinones, and pyridinium salts with tetrahydroxydiboron/water
Li, Tiejun,Peng, Henian,Tang, Wenjun,Tian, Duanshuai,Xu, Guangqing,Yang, He
, p. 4327 - 4337 (2021/05/31)
A series of unsaturated carbonyls, quinones, and pyridinium salts have been effectively reduced to the corresponding saturated carbonyls, dihydroxybenzenes, and hydropyridines in moderate to high yields with tetrahydroxydiboron/water as a mild, convenient, and metal-free reduction system. Deuterium-labeling experiments have revealed this protocol to be an exclusive transfer hydrogenation process from water. This journal is
Synthesis of tetraaryl-p-benzoquinones and 2,3-diaryl-1,4-naphthoquinones via Suzuki-Miyaura cross-coupling reactions
Hassan, Zahid,Ullah, Ihsan,Ali, Iftikhar,Khera, Rasheed Ahmad,Knepper, Ingo,Ali, Asad,Patonay, Tamás,Villinger, Alexander,Langer, Peter
, p. 460 - 469 (2013/02/23)
The palladium-catalyzed Suzuki-Miyaura coupling reaction of tetrabromo-p-benzoquinone and 2,3-dibromonaphthoquinone provide a convenient approach to tetraaryl-p-benzoquinones and 2,3-diarylnaphthoquinones. Suzuki-Miyaura of tetrabromo-1,4-phenylene bis(tr
Thermoresponsive dendrimers based on oligoethylene glycols: Design, synthesis and cytotoxic activity against MCF-7 breast cancer cells
Abdel-Rahman, Mona A.,Al-Abd, Ahmed M.
, p. 848 - 854 (2013/11/06)
Three interesting thermoresponsive branched oligoethylene glycol dendrimers based on tetrabromohydroquinone were efficiently synthesized from tetrabromohydroquinone and three different oligoethylene glycol derivatives. By visual inspection, all these dend
An efficient synthesis of 2,5-diamino-1,4-benzoquinone
Mereyala, Hari Babu,Chary, Mahankhali Venu,Kantevari, Srinivas
, p. 187 - 189 (2007/10/03)
A novel and efficient synthesis of 2,5-diamino-1,4-benzoquinone is described. The reaction involves a palladium/charcoal hydrogenolysis as the key step and provides the desired product in only four steps and very good overall yield. Georg Thieme Verlag Stuttgart.
Photoreaction of nitrobenzenes with hydrobromic acid
McIntyre, Brian P.,Coleman, Brian D.,Wubbels, Gene G.
, p. 7709 - 7711 (2007/10/03)
Nitrobenzene and three derivatives (3-CO2H, 3-OH, and 4-OH) give tribromoanilines when irradiated in hydrobromic acid.
HYDRIDE TRANSFER REACTIONS OF MICHLER'S HYDRIDE WITH DIFFERENT ?-ACCEPTORS
Zaman, Khan. M.,Nishimura, Norio,Yamamoto, Shunzo,Sueishi, Yoshimi
, p. 309 - 315 (2007/10/02)
The hydride transfer reactions of 4,4'-bis(dimethylaminophenyl)methane (Michler's hydride) with p-benzoquinones were studied.The rate of formation of Michler's Hydrol Blue was followed spectrophotometrically.The second-order rate constants and the activation parameters were estimated.The formation of a charge-transfer complex was observed at low temperatures.Stable and unstable paramagnetic species formed during the reactions were assigned by ESR spectroscopy.The observed kinetic behaviour and the stoichiometry were in line with those previously obtained for the systems involving Leuco Crystal Violet, Leuco Malachite Green and Leuco Bindshedler's Green.Hence the reaction is considered to proceed according to the so-far accepted multi-step mechanism.However, when tetracyano-p-quinodimethane or tetracyanoethylene was used as a ?-acceptor, a comparatively stable radical ion pair was formed as a result of a one-electron transfer, followed by the gradual formation of Michler's Hydrol Blue.The kinetic behaviour and the stoichiometry of the reaction were examined, together with the enhanced kinetic effects of added triethylamine.A modified mechanism for these systems is proposed.The role of cyanomethylenes was found to be essentially different from that of p-benzoquinones, and therefore ?-acceptors are divided into two groups of cyanomethylenes and p-benzoquinones.
Reduction of Quinones by Hydride Meisenheimer Adducts
Atkins, Paul J.,Gold, Victor,Wassef, Wasfy N.
, p. 463 - 466 (2007/10/02)
Hydride Meisenheimer adducts, prepared by the reaction of 1,3,5-trinitrobenzene or 2,4-dinitroaniline with tetrahydridoborate ions, can transfer hydride to a range of quinones in dimethyl sulphoxide solution.Rate constants are reported for the 1,3,5-trinitrobenzene adduct and tetrachloro-1,4-benzoquinone, tetrabromo-1,4-benzoquinone, and 2,6-dichloro-1,4-benzoquinone, and for the 2,4-dinitroaniline adduct with 1,4-benzoquinone.The rates increase with increasing reduction potential of the quinone.In all cases the hydroquinones formed are slowly oxidised back to quinones.There are indications that the formation of the products of the hydride transfer is preceded by formation of a species having a low-intensity absorption maximum at > 700 nm, which is tentatively ascribed to a charge-transfer complex. 4-Nitrobenzaldehyde reacts with the hydride adduct of 1,3,5-trinitrobenzene at a much lower rate.All the ractions observed are characterised by low energies of activation (in the range 36-51 kJ mol-1) and large negative entropies of activation.
