نتایج جستجو برای: epoxides
تعداد نتایج: 1664 فیلتر نتایج به سال:
Unlike the facile synthesis of β-monofluoromethyl alcohols by nucleophilic monofluoromethylation of epoxides, the synthesis of β-difluoromethyl alcohols by nucleophilic difluoromethylation of epoxides still remains a challenge. Herein, studies on tackling this problem with PhSO(NTBS)CF2H (2; TBS=tert-butyldimethylsilyl) are reported. The preorganization of 2 and epoxides with BF3⋅Et2O was found...
For the production of cyclic carbonates from cycloaddition CO2 with epoxides, halogen pollution and product purity are two most common problems due to usage homogeneous halogen-containing catalysts such as ammonium salt alkali metal halide. Hence, development a novel, halogen-free efficient catalyst for synthesis high-purity is significant. Here, series acid–base bifunctional Ce1-xZrxO2 nanorod...
epoxides undergo regioselective ring opening with various nucleophiles using catalytic amount of nano magnesium oxide and water as solvent under mild reaction conditions. the remarkable features of this method are improved yields, high regioselectivity, and green chemistry agreement.
Epoxides have recently been identified as important intermediates in the gas phase oxidation of hydrocarbons, and their hydrolysis products have been observed in ambient aerosols. To evaluate the role of epoxides in the formation of secondary organic aerosols (SOA), the kinetics and mechanism of heterogeneous reactions of two model epoxides, isoprene oxide and α-pinene oxide, with sulfuric acid...
Isoprene (the most abundant nonmethane hydrocarbon emitted into the atmosphere) is known to undergo oxidation to 2-methyl-1,2,3,4-butanetetraol, a hydrophilic compound present in secondary organic aerosol (SOA) in the atmosphere. Recent laboratory work has shown that gas phase hydroxy epoxides are produced in the low NOx photooxidation of isoprene and that these epoxides are likely to undergo e...
†̃ †̃bay-region' â€d̃iol-epoxides of PAH are important in their car cinogenic activity. A bay region occurs in PAH when an angu larly fused benzo ring is present (Chart 1). There is now direct evidence from tumorigenicity studies that bay-region diol epoxides of B(a)P (2, 14, 15, 22, 23) and BA (18, 25, 26) are ultimate carcinogenic metabolites. In addition, recent studies have shown that cert...
Organosulfate and nitrate formation and reactivity from epoxides derived from 2-methyl-3-buten-2-ol.
Recent work has suggested that 2-methyl-3-butene-2-ol (MBO)-derived epoxide intermediates are responsible for some of the molecular species commonly found in ambient secondary organic aerosol (SOA). Nuclear magnetic resonance techniques were used to study the reaction kinetics and products of two potential MBO-derived epoxides under acidic solution conditions in the presence of sulfate and nitr...
An efficient and simple method for the preparation of Si-Imidazole-HSO4 functionalized magnetic Fe3O4 nanoparticles (Si-Im-HSO4 MNPs) and used as an efficient and reusable magnetic catalysts for the regioselective ring opening of epoxides under green conditions in water. This catalyst was used for the ring opening of epoxide corresponding to the thiocyanohydrins and azidohydrines. Compared to t...
A simple, efficient, and non-metal-catalyzed synthetic method for allyl-epoxides and diallyl-epoxides by allylation of α-haloketones and esters with allylmagnesium bromide in mild conditions is reported in this article. It inherited some advantages of the organomagnesium reagents such as availability, operational simplicity and low toxicity.
Epoxides and aziridines are common intermediates in synthesis. Readily accessible in enantioenriched form, they are typically used as electrophiles, taking advantage of their predictable highly regioselective ring-opening reactions. Our work in the area of α-lithiated terminal epoxides and aziridines indicates that there are many other less conventional but useful reactions of these small-ring ...
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