94-85-9Relevant academic research and scientific papers
A mild and selective Cu(II) salts-catalyzed reduction of nitro, azo, azoxy, N-aryl hydroxylamine, nitroso, acid halide, ester, and azide compounds using hydrogen surrogacy of sodium borohydride
Kalola, Anirudhdha G.,Prasad, Pratibha,Mokariya, Jaydeep A.,Patel, Manish P.
supporting information, p. 3565 - 3589 (2021/10/12)
The first mild, in situ, single-pot, high-yielding well-screened copper (II) salt-based catalyst system utilizing the hydrogen surrogacy of sodium borohydride for selective hydrogenation of a broad range of nitro substrates into the corresponding amine under habitancy of water or methanol like green solvents have been described. Moreover, this catalytic system can also activate various functional groups for hydride reduction within prompted time, with low catalyst-loading, without any requirement of high pressure or molecular hydrogen supply. Notably, this system explores a great potential to substitute expensive traditional hydrogenation methodologies and thus offers a greener and simple hydrogenative strategy in the field of organic synthesis.
Immobilized iron oxide nanoparticles as stable and reusable catalysts for hydrazine-mediated nitro reductions in continuous flow
Moghaddam, Mojtaba Mirhosseini,Pieber, Bartholom?us,Glasnov, Toma,Kappe, C. Oliver
, p. 3122 - 3131 (2015/09/28)
An experimentally easy to perform method for the generation of alumina-supported Fe3O4 nanoparticles [(6±1)nm size, 0.67 wt%]and the use of this material in hydrazine-mediated heterogeneously catalyzed reductions of nitroarenes to anilines under batch and continuous-flow conditions is presented. The bench-stable, reusable nano-Fe3O4@Al2O3 catalyst can selectively reduce functionalized nitroarenes at 1 mol% catalyst loading by using a 20 mol% excess of hydrazine hydrate in an elevated temperature regime (150°C, reaction time 2-6 min in batch). For continuous-flow processing, the catalyst material is packed into dedicated cartridges and used in a commercially available high-temperature/-pressure flow device. In continuous mode, reaction times can be reduced to less than 1 min at 150°C (30 bar back pressure) in a highly intensified process. The nano-Fe3O4@Al2O3 catalyst demonstrated stable reduction of nitrobenzene (0.5 m in MeOH) for more than 10 h on stream at a productivity of 30mmolh-1 (0.72 mol per day). Importantly, virtually no leaching of the catalytically active material could be observed by inductively coupled plasma MS monitoring.
Hydrazine-mediated reduction of nitro and azide functionalities catalyzed by highly active and reusable magnetic iron oxide nanocrystals
Cantillo, David,Moghaddam, Mojtaba Mirhosseini,Kappe, C. Oliver
, p. 4530 - 4542 (2013/06/05)
Iron oxide (Fe3O4) nanocrystals generated in situ from an inexpensive and readily available iron source catalyze the reduction of nitroarenes to anilines with unparalleled efficiency. The procedure is chemoselective, avoids the use of precious metals, and can be applied under mild reflux conditions (65 or 80 C) or using sealed vessel microwave heating in an elevated temperature regime (150 C). Utilizing microwave conditions, a variety of functionalized anilines have been prepared in nearly quantitative yields within 2-8 min at 150 C, in a procedure also successfully applied to the reduction of aliphatic nitro compounds and azides. The iron oxide nanoparticles are generated in a colloidal form, resulting in homogeneous solutions suitable for continuous flow processing. Selected examples of anilines of industrial importance have been prepared in a continuous regime using this protocol.
In situ generated iron oxide nanocrystals as efficient and selective catalysts for the reduction of nitroarenes using a continuous flow method
Cantillo, David,Baghbanzadeh, Mostafa,Kappe, C. Oliver
, p. 10190 - 10193 (2012/11/07)
The best of both worlds: The benefits of homogeneous and heterogeneous nanocatalysis are combined, whereby highly reactive colloidal Fe 3O4 nanocrystals are generated in situ that remain in solution long enough to allow the efficient and selective reduction of nitroarenes to anilines in continuous-flow mode (see scheme). After completion of the reaction, the nanoparticles aggregate and can be recovered by a magnet. Copyright
A Simple Synthesis of 5-Methoxyindole and 5-Methoxy-2-oxindole
Sakamoto, Takeshi,Hosoda, Isao,Kikugawa, Yasuo
, p. 1279 - 1281 (2007/10/02)
1-Methoxy- and 1-hydroxy-2-oxindoles rearranged in acidic solution to 5-substituted 2-aminophenylacetic acid derivatives which were cyclized to the corresponding 2-oxindoles with heating.The synthesis of 5-methoxyindole from 5-methoxy-2-oxindole was also described.
Rubine disazo acid dyes for polyamides
-
, (2008/06/13)
Dyes of the formula STR1 wherein B and D are each independently 1,4-phenylene or 1,4-naphthylene; M is hydrogen, lithium, sodium, potassium or ammonium; A1 is hydrogen, C1-4 alkoxy, C1-4 alkyl, trifluoromethyl, nitro, chloro, bromo, cyano, or hydroxy; B1 and B2 are each hydrogen, C1-3 alkoxy, C1-3 alkyl, chloro or bromo; D1 is hydrogen, C1-4 alkoxy, C1-4 alkyl, or chloro; D2 is hydrogen, C1-4 alkoxy, C1-4 alkyl, chloro, bromo, fluoro, or acylamino, acyl being C1-5 alkanoyl, C1-5 alkylsulfonyl, benzoyl or benzenesulfonyl, each acyl unsubstituted or substituted with 1 to 3 of C1-2 alkyl, C1-2 alkoxy, chloro, bromo, cyano, or hydroxy; and R1 and R2 are each C1-6 alkyl, C1-6 chloro or bromoalkyl, C2-6 hydroxy- or dihydroxyalkyl, C2-6 alkoxyalkyl, C1-6 cyanoalkyl, or phenyl-C1-2 alkyl (phenyl unsubstituted or substituted with 1 to 3 of C1-2 alkyl, C1-2 alkoxy, chloro, bromo, cyano or hydroxy) are useful in dyeing natural and synthetic polyamide fibers in deep and level shades of red to blue.
