52154-83-3Relevant academic research and scientific papers
A new halide-free efficient reaction-controlled phase-transfer catalyst based on silicotungstate of [(C18H37)2(CH 3)2N]3[SiO4H(WO5) 3] for olefin epoxidation, oxidation of sulfides and alcohols with hydrogen peroxide
Ma, Baochun,Zhao, Wei,Zhang, Fuming,Zhang, Yingshuai,Wu, Songyun,Ding, Yong
, p. 32054 - 32062 (2014/08/18)
A new reaction-controlled phase-transfer catalyst based on silicotungstate of [(C18H37)2(CH3) 2N]3[SiO4H(WO5)3] for oxidation of hydrocarbons is developed. The catalyst is a new heteropoly compound with silicon as heteroatom, which is different to the previously reported reaction-controlled phase transfer catalysts that were composed of quaternary ammonium heteropolyoxotungstates of [π-C5H 5N(CH2)15CH3]3[PW 4O16] and [π-C5H5N(CH 2)15CH3]3[PW4O 32] with phosphorus as heteroatom. The oxidation of various alkenes (such as linear terminal olefins, internal olefins, cyclic olefins and unactivated alkenes) to epoxides, sulfides to sulfoxides and sulfones, alcohols to carbonyl compounds, are successfully catalyzed by this recyclable and environmentally benign catalyst using H2O2 as oxidant and ethyl acetate as solvent. This catalyst is not only capable of catalyzing homogeneous oxidation of organic substrates with unique reaction-controlled phase-transfer character, but also avoids the use of toxic solvents. The catalyst could be easily recovered and reused after reaction, and the epoxidation of cyclohexene was performed twenty times without obvious loss in activity. The fresh catalyst and the used one were characterized by ICP, IR, UV-vis, 29Si MAS NMR and 183W NMR in detail. the Partner Organisations 2014.
Organocatalyzed epoxidation of alkenes in continuous flow using a multi-jet oscillating disk reactor
Spaccini, Raffaele,Liguori, Lucia,Punta, Carlo,Bj?rsvik, Hans-René
scheme or table, p. 261 - 265 (2012/05/05)
The times are changing: A batch process, the Minisci epoxidation, is transformed into a continuous-flow protocol for the selective aerobic radical epoxidation of alkenes. The use of a novel reactor type allows to considerably shorten reactor residence times. Experimental results suggest that two different reaction mechanisms exist for the oxidation: one for the batch conditions and a different one for flow synthesis protocol. Copyright
Synthesis of epoxides catalyzed by a halide-free reaction-controlled phase-transfer catalytic system: [(CH3(CH2) 17)2N(CH3)2]3[PW 4O32]/H2O2/Dioxan/Olefin
Ding, Yong,Ma, Baochun,Tong, Dejie,Hua, Hui,Zhao, Wei
experimental part, p. 739 - 746 (2010/02/16)
The epoxidation of alkenes was successfully catalyzed by a recyclable catalytic system: [(CH3(CH2)17) 2N(CH3)2]3[PW4O 32]/H2O2/dioxan/olefin. This new catalytic system is not only capable of catalyzing homogeneous epoxidation of alkenes with a unique reaction-controlled phase-transfer character, but also avoids the use of chlorinated solvents. The reactions were conducted in a biphasic mixture of aqueous H2O2/dioxan, and many kinds of alkenes could be efficiently converted to the corresponding epoxides in high yields. Both new and used [(CH3(CH2)17)2N(CH 3)2]3[PW4O32] catalyst was characterized by 31P magic angle spin NMR, and IR. CSIRO 2009.
Substrate-induced diastereoselectivity in the dimethyldioxirane epoxidation of simple alkenes and dienes
Asouti,Hadjiarapoglou
, p. 1847 - 1850 (2007/10/03)
Various alkenes and dienes, such as (R)- or (S)-limonene 2, 2-carene 6, 3-carene 8, (R)-α-pinene 10, (S)-α-pinene 12, and endo-dicyclopentadiene 14 were transformed into the corresponding mono- and bis-epoxides by epoxidation with dimethyldioxirane (as an acetone solution). The selectivity observed in these epoxidations is explained by the assumption of hydrogen bonding between bridge protons and the dioxirane.
Regioselective and diastereoselective dimethyldioxirane epoxidation of substituted norbornenes and hexamethyl Dewar benzene
Asouti, Amalia,Hadjiarapoglou, Lazaros P.
, p. 539 - 542 (2007/10/03)
Various substituted norbornenes, such as endo-dicyclopentadiene 1, exo- dicyclopentadiene 5, 5-methylenebicyclo[2.2.1]hept-2-ene 8 and hexamethyl Dewar benzene 10 were transformed into the corresponding mono- and bis- epoxides by epoxidation with dimethyldioxirane (as an acetone solution).
Oxidation of Organic Substrates by Molecular Oxygen/Aldehyde/ Heteropolyoxometalate System
Hamamoto, Masatoshi,Nakayama, Kouichi,Nishiyama, Yutaka,Ishii, Yasutaka
, p. 6421 - 6425 (2007/10/02)
Heteropolyoxometalate-catalyzed oxidations of organic compounds such as olefins and cyclic ketones with molecular oxygen in the presence of an aldehyde were examined.Olefins were epoxidized with dioxygen in the presence of 2 equiv of 2-methylpropanal under the influence of a catalytic amount of the mixed heteropolyoxometalate NPV6Mo6 (3) to give the corresponding epoxides in moderate to good yields.This catalytic oxidation method was also applied to the epoxidation of allylic and homoallylic alcohols.In the absence of olefins, the aldehydes were efficiently convertedinto the corresponding carboxylic acids.In addition, the Baeyer-Villiger oxidation of cyclic ketones was accomplished by using benzaldehyde instead of 2-methylpropanal as the aldehyde.
SODIUM PERBORATE OXIDATIONS OF CYCLIC AND ACYCLIC ALKENES TO OXIRANES OR VICINAL ACETOXY ALCOHOLS
Xie, Gaoyang,Xu, Linxiao,Hu, Jun,Ma, Shiming,Hou, Wei,Tao, Fenggang
, p. 2967 - 2968 (2007/10/02)
Under different reaction conditions, sodium perborate/acetic anhydride oxidizes alkenes into oxiranes or vicinal acetoxy alcohols in good yields.
Dicyclopentadiene Oxidation. IV. Oxidation of 4,5- and 8,9-Dihydro-dicyclopentadiene
Schnurpfeil, D.,Lauterbach, G.
, p. 121 - 128 (2007/10/02)
A mixture of exo- and endo-4,5-dihydro-dicyclopentadiene 5 and also pure endo-8,9-dihydro-dicyclopentadiene 7 and pure exo-dicyclopentadiene 10 was oxidized in the absence and in the presence of catalysts.The compounds containing the norbornene structure mainly gave the corresponding exo-epoxides.No catalytic effects were observed in the formation of these norbornene epoxides.Compound 7 containing only the cyclopentene structure mainly yielded the corresponding hydroperoxide 9.In this case a catalytic effect of epoxidation catalysts was observed : in the presence of such catalysts the epoxide was increased. The results obtained prove the mechanism of dicyclopentadiene oxidation proposed by us.
Dicyclopentadiene Oxidation. II. Catalyzed Liquid-Phase Oxidation of Dicyclopentadiene
Schnurpfeil, D.
, p. 842 - 847 (2007/10/02)
The liquid-phase oxidation of dicyclopentadiene 1 by molecular oxygen was studied in the presence of MoO2(acac)2 as a typical epoxidation catalyst.The yield of the mono-epoxides 2 and 3 is increased to 56.4 percent (uncatalyzed reaction: 43.6 percent).The ratio of the two mono-epoxides is decreased to 2/3 = 2.6 in relation to the uncatalyzed reaction 2/3 = 7.1).The influence of temperature, conversion and solvents is described.The bisepoxide 4 is formed at lower conversions than in the uncatalyzed reaction.But also at higher conversion of 1 not more than 10 percent of the bisepoxide 4 is formed.
