- Solid supported platinum(0) nanoparticles catalyzed chemo-selective reduction of nitroarenes to N-arylhydroxylamines
-
Solid supported platinum(0) (SS-Pt) nanoparticles were developed as a heterogeneous catalyst following a reduction/deposition method and characterized by SEM, TEM, EDX and XRD analysis. The SS-Pt catalyst was applied in the chemo-selective reduction of nitroarenes to N-arylhydroxylamines using hydrazine hydrate as a hydrogen source. A wide variety of reducible functional groups such as halides, carboxylic acids, esters, amides, nitriles, keto, alkenes, alkynes and N-benzyl were well tolerated under the reaction conditions. This process was further successfully employed in 10 g scale reactions. N-Arylhydroxylamines were further applied for catalyst free synthesis of azoxybenzenes. Moreover, use of PEG-400 as cheap reaction medium, additive free methodology and the recyclability of SS-Pt catalyst up to ten times without significant loss of catalytic activity evidently follow the principles of green chemistry.
- Shil, Arun K.,Das, Pralay
-
supporting information
p. 3421 - 3428
(2013/12/04)
-
- Synthesis of photo-responsive acridine-modified DNA and its application to site-selective RNA scission
-
Photo-responsive phosphoramidite monomers, which bear an azobenzene between acridine and the phosphoramidite unit, were synthesized, and incorporated into oligonucleotides. Upon UV irradiation, the azobenzene in the modified DNA efficiently isomerized from the trans isomer into the cis isomer. Although the Tm values of their duplexes with complementary DNA were not much changed by the isomerization, site-selective RNA scission was significantly accelerated by the UV irradiation when Mn(II) ion was used as the catalyst for RNA scission. Copyright Taylor & Francis Group, LLC.
- Tanaka, Keita,Yamamoto, Yoji,Kuzuya, Akinori,Komiyama, Makoto
-
p. 1175 - 1185
(2008/12/23)
-
- Aromatic aldonitrones of 2-(hydroxyamino)benzyl alcohol and their cyclic isomers. Crystal and molecular structures of a 1-hydroxy-1,2-dihydro-4H-3,1-benzoxazine, a boron chelate, and its parent nitrone ligand
-
The synthesis of a series of C-aryl-N-[2-(hydroxymethyl)phenyl]nitrones, 5 (that can also exist under certain conditions as isomeric 1-hydroxy-2-aryl-1,2-dihydro-4H-3,1-benzoxazines, 8), via 2-(hydroxyamino)benzyl alcohol, 4, and their subsequent reaction
- Kliegel,Metge,Rettig,Trotter
-
p. 389 - 399
(2007/10/03)
-
- Kinetics and Mechanism of Polarographic Reduction of Aromatic Nitro Compounds in Aqueous Alcoholic Medium
-
Polarographic reduction of nitrobenzene, ortho-, meta- and para- chloronitrobenzenes, nitrotoluenes, nitrophenols and nitrobenzaldehydes has been studied in 25percent (v/v) aqueous ethanolic solutions, using Britton-Robinson (BR) buffer of varying pH values.KCl (0.1 M) has been used as the supporting electrolyte and Triton X-100 (0.001percent) as the maxima suppressor.The potential-dependent rate constant, kf,h has been calculated by Koutecky's method at different pH values and the values of kinetic parameters (αna and kf,h) have been calculated from logkf,h versus Ed.e. plots which are linear thereby suggesting that only a single rate-determining step is involved in the electrode process of each depolarizer.Based on the values of kinetic parameter, αna and the variation of E1/2 with pH, the stoichiometry of the rate-determining step has been established.This has led to the postulation of a tentative mechanism for the polarographic reduction of each depolarizer.Besides, the effect of the nature and position of various substituents, viz.Cl, CH3, OH and CHO on the kinetics of the polarographic reduction of NO2 group has been investigated.
- Ratan, Ram,Rani, Rama,Singh, Mukhtar
-
p. 664 - 670
(2007/10/02)
-