95-54-5Relevant articles and documents
Catalytic effect of alloxazinium and isoalloxazinium salts on oxidation of sulfides with hydrogen peroxide in micellar media
Cibulka, Radek,Baxova, Lenka,Dvorakova, Hana,Hampl, Frantisek,Menova, Petra,Mojr, Viktor,Plancq, Baptiste,Serkan, Sayin
, p. 973 - 993 (2009)
Three novel amphiphilic alloxazinium salts were prepared: 3-dodecyl-5-ethyl-7,8,10-trimethylisoalloxazinium perchlorate (1c), 1-dodecyl-5-ethyl-3-methylalloxazinium perchlorate (2b), and 3-dodecyl-5-ethyl-l-methylalloxazinium perchlorate (2c). Their catalytic activity in thioanisole (3) oxidation with hydrogen peroxide was investigated in micelles of sodium dodecylsulfate (SDS), hexadecyltrimethylammonium nitrate (CTANO3) and Brij 35. Reaction rates were strongly dependent on the catalyst structure, on the type of micelles, and on pH value. Alloxazinium salts 2 were more effective catalysts than isoalloxazinium salts 1. Due to the contribution of micellar catalysis, the vcat/vo ratio of the catalyzed and non-catalyzed reaction rates was almost 80 with salt 2b solubilized in CTANO3 micelles. Nevertheless, the highest acceleration was observed with non-amphiphilic 5-ethyl-1,3-dimethylalloxazinium perchlorate (2a) in CTANO3 micelles (vcat/vo = 134). In this case, salt 2a presumably acts as a phase-transfer catalyst bringing hydrogen peroxide from the aqueous phase into the micelle interior. Synthetic applicability of the investigated catalytic systems was verified on semipreparative scale.
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Imaizumi et al.
, p. 1507 (1978)
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Nickel Boride Catalyzed Reductions of Nitro Compounds and Azides: Nanocellulose-Supported Catalysts in Tandem Reactions
Proietti, Giampiero,Prathap, Kaniraj Jeya,Ye, Xinchen,Olsson, Richard T.,Dinér, Peter
, p. 133 - 146 (2021/11/04)
Nickel boride catalyst prepared in situ from NiCl2 and sodium borohydride allowed, in the presence of an aqueous solution of TEMPO-oxidized nanocellulose (0.01 wt%), the reduction of a wide range of nitroarenes and aliphatic nitro compounds. Here we describe how the modified nanocellulose has a stabilizing effect on the catalyst that enables low loading of the nickel salt pre-catalyst. Ni-B prepared in situ from a methanolic solution was also used to develop a greener and facile reduction of organic azides, offering a substantially lowered catalyst loading with respect to reported methods in the literature. Both aromatic and aliphatic azides were reduced, and the protocol is compatible with a one-pot Boc-protection of the obtained amine yielding the corresponding carbamates. Finally, bacterial crystalline nanocellulose was chosen as a support for the Ni-B catalyst to allow an easy recovery step of the catalyst and its recyclability for new reduction cycles.
Development of sustainable and efficient nanocatalyst based on polyoxometalate/nickel oxide nanocomposite: A simple and recyclable catalyst for reduction of nitroaromatic compounds
Kurbah, Sunshine Dominic
, p. 1487 - 1495 (2021/04/22)
In this paper, we report the synthesis and characterization of NiO@PolyMo nanocomposite. The newly synthesized nanocomposite was characterized by transmission electronmicroscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and powder X-ray diffraction (XRD). The particle sizes of the NiO@PolyMo nanocatalyst are in the range of 10–20 nm. Powder XRD patterns show that the phase of NiO@PolyMo remains unaltered even after the functionalization of NiO. The lattice fringes of d = 0.20 nm were observed, which correspond to the (111) plane of NiO phase. The newly synthesized material shows excellent catalytic performance and good selectivity for reduction of nitroarenes. The advantages of the present protocols are mild, and can be carried out using water as a solvent, which is an eco-friendly benign.
Chemoselective Hydrogenation of Nitroarenes Using an Air-Stable Base-Metal Catalyst
Zubar, Viktoriia,Dewanji, Abhishek,Rueping, Magnus
supporting information, p. 2742 - 2747 (2021/05/05)
The reduction of nitroarenes to anilines as well as azobenzenes to hydrazobenzenes using a single base-metal catalyst is reported. The hydrogenation reactions are performed with an air-and moisture-stable manganese catalyst and proceed under relatively mild reaction conditions. The transformation tolerates a broad range of functional groups, affording aniline derivatives and hydrazobenzenes in high yields. Mechanistic studies suggest that the reaction proceeds via a bifunctional activation involving metal-ligand cooperative catalysis.