- Facile reduction of nitroarenes into anilines and nitroalkanes into hydroxylamines via the rapid activation of ammonia· borane complex by supported gold nanoparticles
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Gold nanoparticles supported on titania catalyse, even at a ppm loading level, the quantitative reduction of nitroarenes into anilines and nitroalkanes into alkylhydroxylamines by the ammonia× borane complex. No dehalohalogenation was seen in the case of chloro- or bromonitroarenes, while ester, cyano, or carboxylic acid functionalities also remain intact. The nitroarene to aniline reduction pathway does not require nitrosoarenes as intermediate products. Copyright
- Vasilikogiannaki, Eleni,Gryparis, Charis,Kotzabasaki, Vasiliki,Lykakis, Ioannis N.,Stratakis, Manolis
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supporting information
p. 907 - 911
(2013/05/08)
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- One-pot synthesis of dihydrobenzisoxazoles from hydroxylamines, acetylenedicarboxylates, and arynes via in situ generation of nitrones
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Aryne [3 + 2] cycloaddition with nitrones generated in situ from the addition of hydroxylamines to acetylenedicarboxylates affords moderate to good yields of dihydrobenzisoxazoles. This reaction extends the current scope of aryne cycloaddition to include in situ generated nitrones and produces functionalized dihydrobenzisoxazoles with a quaternary center.
- Li, Pan,Wu, Chunrui,Zhao, Jingjing,Li, Yang,Xue, Weichao,Shi, Feng
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- Practical synthesis and evaluation of the biological activities of 1α,25-dihydroxyvitamin D3 antagonists, 1α,25- dihydroxyvitamin D3-26,23-lactams. Designed on the basis of the helix 12-folding inhibition hypothesis
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A practical synthetic route to novel vitamin D antagonists of DLAM (1α,25-dihydroxyvitamin D3-26,23-lactam) was developed from vitamin D2 via the 1,3-dipolar cycloaddition reaction as a key step. Six DLAM derivatives (24 compounds) w
- Nakano, Yusuke,Kato, Yuko,Imai, Keisuke,Ochiai, Eiji,Namekawa, Jun-Ichi,Ishizuka, Seiichi,Takenouchi, Kazuya,Tanatani, Aya,Hashimoto, Yuichi,Nagasawa, Kazuo
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p. 2398 - 2406
(2007/10/03)
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- Vitamin D3 lactam derivative
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Compounds expressed by the following formula (1) or pharmaceutically permissible solvate thereof which is effective for treating Paget's disease of bone, hypercalcemia or osteoporosis. In the formula, R1 is a C2-C10 alkyl
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Page/Page column 5
(2008/06/13)
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- Synthesis of N-substituted N-nitrosohydroxylamines as inhibitors of mushroom tyrosinase
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A series of N-substituted N-nitrosohydroxylamines including six new compounds were synthesized and examined for inhibition of mushroom tyrosinase. Corresponding hydroxylamines were reacted with n-butyl nitrite to give substituted nitrosohydroxylamines as their ammonium salt. The N-substituted hydroxylamines were prepared from the primary amines via the oxaziridine, or from the carbonyl compounds via the oxime. Most of the nitrosohydroxylamines tested inhibited mushroom tyrosinase. Among them, N-cyclopentyl-N-nitrosohydroxylamine exhibited the most potent activity (IC50=0.6 μM), as powerful as that of tropolone, one of the most powerful inhibitors. As removal of nitroso or hydroxyl moiety, the enzyme inhibitory activity was completely diminished. Both N-nitroso group and N-hydroxy group were suggested to be essential for the activity, probably by interacting with the copper ion at the active site of the enzyme. Lineweaver-Burk plotting showed that cupferron was a competitive inhibitor but that N-cyclopentyl-N-nitrosohydroxylamine was not.
- Shiino, Mitsuhiro,Watanabe, Yumi,Umezawa, Kazuo
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p. 1233 - 1240
(2007/10/03)
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- A novel transformation of primary amines to N-monoalkylhydroxylamines
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A novel transformation of primary amines to the corresponding N-monoalkylhydroxylamines is described. The three-step protocol involves selective mono-cyanomethylation of primary amines, regioselective formation of nitrones by m-CPBA oxidation, and hydroxylaminolysis of the nitrones with hydroxylamine hydrochloride. The method is applicable for a wide range of primary amines, including alkyl, benzyl, and chiral.
- Tokuyama,Kuboyama,Amano,Yamashita,Fukuyama
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p. 1299 - 1304
(2007/10/03)
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