Search results for "Phosgene"
showing 6 items of 6 documents
Carbon dioxide conversion to dimethyl carbonate: The effect of silica as support for SnO2 and ZrO2 catalysts
2011
International audience; Abundant in nature, CO2 poses few health hazards and consequently is a promising alternative to phosgene feedstock according with the principles of Green Chemistry and Engineering. The synthesis organic carbonates from CO2 instead of phosgene is highly challenging as CO2 is much less reactive. As part of our ongoing research on the investigation of catalysts for dimethyl carbonate (DMC) synthesis from methanol and CO2, we herein report results aimed at comparing the catalytic behavior of new SnO2-based catalysts with that of ZrO2. Silica-supported SnO2 and ZrO2 exhibit turnover numbers which are an order of magnitude higher than those of the unsupported oxides. Tin-b…
Reactivity difference between diphosgene and phosgene in reaction with (2,3-anti)-3-amino-1,2-diols
2006
In reactions of (2,3-anti)-3-amino-1,2-diols with diphosgene and phosgene and their conversion into 1,3-oxazolidin-2-ones, some differences in the stereochemistry of the reactions have been found with these two reagents. The reactions with phosgene afforded the expected cis-oxazolidinones, and in the reaction with diphosgene under the same reaction conditions, the trans-oxazolidinones were also obtained.
New Fluorinated 1,3-Vinylogous Amidines as Versatile Intermediates: Synthesis of Fluorinated Pyrimidin-2(1H)-ones.
2006
The condensation of the azaenolates derived from readily available ketimines with fluorinated nitriles offers an efficient and straightforward entry to new fluorinated 1,3-vinylogous amidines. These versatile compounds, in turn, react with triphosgene to yield new fluorinated pyrimidin-2(1H)-ones in high yields.
Direct electrochemical generation of organic carbonates by dehydrogenative coupling.
2018
Organic carbonates are an important source for polycarbonate synthesis. However, their synthesis generally requires phosgene, sophisticated catalysts, harsh reaction conditions, or other highly reactive chemicals. We present the first direct electrochemical generation of mesityl methyl carbonate by C–H activation. Although this reaction pathway is still challenging concerning scope and efficiency, it outlines a new strategy for carbonate generation.
An efficient synthesis of uracil derivatives from 2-alkyl-Δ2-oxazolines and nitriles
2008
An efficient and convenient synthesis of new fluorinated and non-fluorinated uracils is described herein. The condensation of nitriles with enolates generated from 2-alkyl-Δ 2 -oxazolines (I) affords fluorinated β-enamino acid derivatives, which react with triphosgene to give an isomeric mixture of oxazolopyrimidinones. These can then be easily transformed into a single C-6 pyrimidindione derivative through reaction with a suitable nucleophile.
Linear Organic Carbonates
2003
The most common and successful method for producing organic carbonates, including polycarbonates, has been based for long time on the reaction between an alcohol or phenol and phosgene. The existing strict environmental regulations and the expanding market for organic carbonates do not assure that this technology can continue to have a leading role in this area, due to the inherent riskfulness of the processes. The market expansion of dimethyl carbonate (DMC), diphenyl carbonate (DPC), and bisphenol A polycarbonate (BPA-PC) is a reality, finding its driving force from the industrialization of alternative routes by EniChem (Italy) and UBE (Japan). This favorable situation can be foreseen for…