121-14-2Relevant articles and documents
Okamoto,Attarwala
, p. 3269,3271 (1979)
Fluoropolymer-Coated PDMS Microfluidic Devices for Application in Organic Synthesis
Yang, Tianjin,Choo, Jaebum,Stavrakis, Stavros,de Mello, Andrew
, p. 12078 - 12083 (2018)
In recent years there has been huge interest in the development of microfluidic reactors for the synthesis of small molecules and nanomaterials. Such reaction platforms represent a powerful and versatile alternative to traditional formats since they allow for the precise, controlled, and flexible management of reactive processes. To date, the majority of microfluidic reactors used in small-molecule synthesis have been manufactured using conventional lithographic techniques from materials such as glasses, ceramics, stainless steel, and silicon. Surprisingly, the fabrication of microfluidic devices from such rigid materials remains ill-defined, complex, and expensive. Accordingly, the microfluidic toolkit for chemical synthesis would significantly benefit from the development of solvent-resistant microfluidic devices that can be manufactured using soft-lithographic prototyping methods. Whilst significant advances in the development of solvent-resistant polymers have been made, only modest steps have been taken towards simplifying their use as microfluidic reactors. Herein, we emphasize the benefits of using a commercially available, amorphous perfluorinated polymer, CYTOP, as a coating with which to transform PDMS into a chemically inert material for use in organic synthesis applications. Its efficacy is demonstrated through the subsequent performance of photooxidation reactions and reactions under extremely acidic or basic conditions.
Control over m-nitrotoluene concentration in products of heterogeneous mononitration of toluene
Artemov,Tselinskii,Kukushkin,Filatova,Ashikhin
, p. 2063 - 2072 (2007)
Heterogeneous mononitration of toluene with sulfuric-nitric acid mixtures, occurring in the charged interfacial monolayer with high para selectivity, was studied. Ways to suppress the meta substitution in the toluene mononitration stage by controlling the nitrating mixture composition, process parameters, and catalytic additives were found.
Regioselective double Kyodai nitration of toluene and chlorobenzene over zeolites. High preference for the 2,4-dinitro isomer at the second nitration stage
Peng, Xinhua,Suzuki, Hitomi
, p. 3431 - 3434 (2001)
(matrix presented) The Kyodai nitration of toluene and chlorobenzene has been examined in the presence of a solid inorganic catalyst (montmorillonite K10, zeolite HZSM-5, or HBEA-25). Regioselection was quite low at the mononitration stage, but a considerably high preference for the 2,4-isomer was observed at the dinitration stage.
Eisen,Siskind
, p. 996,997 (1964)
Hafnium(IV) and zirconium(IV) triflates as superior recyclable catalysts for the atom economic nitration of o-nitrotoluene
Waller, Francis J.,Barrett, Anthony G. M.,Braddock, D. Christopher,Ramprasad, Dorai
, p. 1641 - 1642 (1998)
The hydrated group 4 metal triflates, Hf(OTf)4 and Zr(OTf)4, were found to be excellent catalysts (10 mol%) for the mononitration of o-nitrotoluene using a single equivalent of concentrated (69%) nitric acid. The only side product is water and the catalysts are readily recycled from the aqueous phase and re-used.
Tris(trifluoromethanesulfonyl)methide ('triflide') anion: Convenient preparation, X-ray crystal structures, and exceptional catalytic activity as a counterion with ytterbium(III) and scandium(III)
Waller, Francis J.,Barrett, Anthony G. M.,Braddock, D. Christopher,Ramprasad, Dorai,McKinnell, R. Murray,White, Andrew J. P.,Williams, David J.,Ducray, Richard
, p. 2910 - 2913 (1999)
-
Nitration of aromatics with dinitrogen pentoxide in a liquefied 1,1,1,2-tetrafluoroethane medium
Fauziev, Ruslan V.,Kharchenko, Alexandr K.,Kuchurov, Ilya V.,Zharkov, Mikhail N.,Zlotin, Sergei G.
, p. 25841 - 25847 (2021/08/09)
Regardless of the sustainable development path, today, there are highly demanded chemical productions still operating that bear environmental and technological risks inherited from the previous century. The fabrication of nitro compounds, and nitroarenes in particular, is traditionally associated with acidic wastes formed in nitration reactions exploiting mixed acids. However, nitroarenes are indispensable for industrial and military applications. We faced the challenge and developed a greener, safer, and yet effective method for the production of nitroaromatics. The proposed approach comprises the application of an eco-friendly nitrating agent, namely dinitrogen pentoxide (DNP), in the medium of liquefied 1,1,1,2-tetrafluoroethane (TFE) - one of the most non-hazardous Freons. Importantly, the used TFE is not emitted into the atmosphere but is effortlessly recondensed and returned into the process. DNP is obtainedviathe oxidation of dinitrogen tetroxide with ozone. The elaborated method is characterized by high yields of the targeted nitro arenes, mild reaction conditions, and minimal amount of easy-to-utilize wastes.
The polyhedral nature of selenium-catalysed reactions: Se(iv) species instead of Se(vi) species make the difference in the on water selenium-mediated oxidation of arylamines
Capperucci, Antonella,Dalia, Camilla,Tanini, Damiano
supporting information, p. 5680 - 5686 (2021/08/16)
Selenium-catalysed oxidations are highly sought after in organic synthesis and biology. Herein, we report our studies on the on water selenium mediated oxidation of anilines. In the presence of diphenyl diselenide or benzeneseleninic acid, anilines react with hydrogen peroxide, providing direct and selective access to nitroarenes. On the other hand, the use of selenium dioxide or sodium selenite leads to azoxyarenes. Careful mechanistic analysis and 77Se NMR studies revealed that only Se(iv) species, such as benzeneperoxyseleninic acid, are the active oxidants involved in the catalytic cycle operating in water and leading to nitroarenes. While other selenium-catalysed oxidations occurring in organic solvents have been recently demonstrated to proceed through Se(vi) key intermediates, the on water oxidation of anilines to nitroarenes does not. These findings shed new light on the multifaceted nature of organoselenium-catalysed transformations and open new directions to exploit selenium-based catalysis.