3066-65-7Relevant articles and documents
Visible-light photocatalyzed oxidative decarboxylation of oxamic acids: a green route to urethanes and ureas
Pawar, Govind Goroba,Robert, Frédéric,Grau, Etienne,Cramail, Henri,Landais, Yannick
supporting information, p. 9337 - 9340 (2018/08/31)
A sustainable metal-free route to urethanes and ureas based on a photocatalyzed oxidative decarboxylation of oxamic acids is described. The reaction includes in situ generation of an isocyanate from the oxamic acid, using an organic dye as a photocatalyst, a hypervalent iodine reagent as an oxidant and a light source, which trigger the free-radical decarboxylation. This protocol successfully avoids the isolation, purification and storage of carcinogenic isocyanates and allows elaboration of urethanes and ureas in a one-pot process from commercially available sources.
Immobilisation of iron tris(β-diketonates) on a two-dimensional flat amine functionalised silicon wafer: A catalytic study of the formation of urethane, from ethanol and a diisocyanate derivative
Conradie,Conradie,Erasmus
, p. 52 - 59 (2014/06/10)
A series of immobilised iron tris(β-diketonato) catalysts on a Si-wafer was prepared, by covalently anchoring the Fe(β-diketonato) 3 complexes [where β-diketonato = (RCOCHCOR′)-, with 1 = acac (R = CH3; R′ = CH3), 2 = dbm (R = C6H5; R′ = C6H5), 3 = tfaa (R = CH3; R′ = CF3), and 4 = hfaa (R = CF3; R′ = CF3)], onto an aminated functionalised Si-wafer. These new catalysts were characterised by X-ray photo-electron spectroscopy (XPS) and atomic force microscopy (AFM). XPS data revealed that ca. 27-91% of all the amine groups anchored the catalyst, Fe(β-diketonato)3. Different Gaussian peaks could be fitted into the F 1s peak, due to the fluorine either being positioned adjacent to the -C-O-Fe-, or to the -C-N-Fe-. The binding energy of the Fe 2p3/2 peak varied between ca. 710.4 and 711.0 eV, depending on the electron donating properties of the R-groups on the β-diketonato ligands, expressed as the sum of the Gordy group electronegativities of the R-groups in the β-diketonato ligands. The AFM photographs showed that the surface changed dramatically after each treatment: after amination (binding of the aminate silane onto the hydroxylate Si-wafer) the Si-wafer turned from flat with a few spikes, to a very wavy surface with smooth lumps. The surface topography again changed, after covalent anchoring of the iron tris(β-diketonato) complexes, to a nodular surface with poorly defined grain boundaries. These immobilised iron tris(β-diketonato) on Si-wafer catalysts, were evaluated for their catalytic activity, during the formation of hexamethylenediurethane from hexamethylenediisocyanate and ethanol. The TOF varied between 15 and 46 s-1, depending on the electron donating properties of the R-groups on the β-diketonato ligands. The more electron donating the R groups, the higher the TOF.
METHOD FOR PRODUCING CARBAMATE COMPOUND
-
Page/Page column 15, (2011/06/24)
A task of the present invention is to provide a process for preparation a carbamate compound using a carbonic acid ester and an amide compound in the presence of a basic compound(s), wherein the process is a novel industrial method which is advantageous in that the reaction rate is faster than conventional and the by-produced ester compound can be recovered, and the present invention is directed to a method comprising reacting an amide compound represented by the formula (1) with a carbonic acid ester represented by the formula (2) in the presence of a basic compound(s) to obtain a carbamate compound represented by the formula (3).
