Activation of H<sub>2</sub>O<sub>2</sub> over Zr(IV). Insights from Model Studies on Zr-Monosubstituted Lindqvist Tungstates
作者:Nataliya V. Maksimchuk、Vasilii Yu. Evtushok、Olga V. Zalomaeva、Gennadii M. Maksimov、Irina D. Ivanchikova、Yuriy A. Chesalov、Ilia V. Eltsov、Pavel A. Abramov、Tatyana S. Glazneva、Vadim V. Yanshole、Oxana A. Kholdeeva、R. John Errington、Albert Solé-Daura、Josep M. Poblet、Jorge J. Carbó
DOI:10.1021/acscatal.1c02485
日期:2021.8.20
(Bu4N)2[W5O18Zr(H2O)3] (1) and (Bu4N)6[W5O18Zr(μ-OH)}2] (2), have been employed as molecular models to unravel the mechanism of hydrogen peroxide activation over Zr(IV) sites. Compounds 1 and 2 are hydrolytically stable and catalyze the epoxidation of C═C bonds in unfunctionalized alkenes and α,β-unsaturated ketones, as well as sulfoxidation of thioethers. Monomer 1 is more active than dimer2. Acid
Zr-单取代的 Lindqvist 型多金属氧酸盐 (Zr-POM),(Bu 4 N) 2 [W 5 O 18 Zr(H 2 O) 3 ] ( 1 ) 和 (Bu 4 N) 6 [W 5 O 18 Zr( μ-OH)} 2 ] ( 2 ),已被用作分子模型来揭示过氧化氢在 Zr(IV) 位点上的活化机制。化合物1和2具有水解稳定性,可催化未官能化烯烃和 α,β-不饱和酮中 C=C 键的环氧化以及硫醚的磺化氧化。单体1比二聚体2更活跃。酸添加剂大大加速了氧化反应,并将氧化剂利用效率提高到>99%。产物分布表明异裂氧转移机制,该机制涉及在 Zr-POM 和 H 2 O 2相互作用时形成的亲电氧化物质。1和2与 H 2 O 2的相互作用以及由此产生的过氧衍生物已通过 UV-vis、FTIR、拉曼光谱、HR-ESI-MS 和组合 HPLC-ICP-原子发射光谱技术进行了研究。一个之间的相互作用17
An Effective Synthesis of Acid-Sensitive Epoxides via Oxidation of Terpenes and Styrenes Using Hydrogen Peroxide under Organic Solvent-Free Conditions
An efficient epoxidation process for various terpenes and styrenes using a hydrogen peroxide-tungsten catalytic system with organic solvent- and halide-free conditions was developed. In the presence of the catalytic system, Na2WO4, PhP(O)(OH)2, and [Me(n-C8H17)3N]HSO4, and under weak acidic conditions, hydrogen peroxide successfully epoxidized α-pinene to α-pinene oxide in 95% selectivity at 91% conversion
开发了一种在无有机溶剂和无卤化物条件下使用过氧化氢-钨催化体系对各种萜烯和苯乙烯进行高效环氧化的方法。在催化体系Na 2 WO 4,PhP(O)(OH)2和[Me(n -C 8 H 17)3 N] HSO 4的存在下,在弱酸性条件下,过氧化氢成功地环氧化了α -pine烯至α-pine烯氧化物的转化率为95%,转化率为91%,而先前公布的利用NH 2 CH 2 P(O)(OH)2作为促进剂的条件没有提供环氧化物。 氧化-催化-环氧化物-萜类化合物-苯乙烯
METHOD FOR MANUFACTURING AN EPOXY COMPOUND AND METHOD FOR EPOXIDIZING A CARBON-CARBON DOUBLE BOND
申请人:Takumi Kiyoshi
公开号:US20120108830A1
公开(公告)日:2012-05-03
The present invention provides a method for producing an epoxy compound, comprising oxidizing a carbon-carbon double bond of an organic compound by hydrogen peroxide in the presence of a neutral inorganic salt and a mixed catalyst of a tungsten compound (a), at least one phosphorus compound selected from the group consisting of phosphoric acids, phosphonic acids, and salts thereof (b) and a surfactant (c), and an epoxidizing method comprising oxidizing a carbon-carbon double bond by hydrogen peroxide in the presence of the catalyst and the neutral inorganic salt.
Unique Salt Effect on Highly Selective Synthesis of Acid-Labile Terpene and Styrene Oxides with a Tungsten/H2O2 Catalytic System under Acidic Aqueous Conditions
styrene oxides are effectively synthesized in high yields with good selectivities using tungsten-catalyzed hydrogen peroxide epoxidation in the presence of Na2SO4. The salt effect is thought to originate with the addition of a saturated amount of Na2SO4 to aqueous H2O2; this addition strongly inhibited the undesired hydrolysis of the acid-labile epoxy products, despite the biphasic conditions of substrate
摘要 在Na 2 SO 4的存在下,使用钨催化的过氧化氢环氧化,可以高产率,高选择性地有效合成酸不稳定的环氧化物,例如萜烯和氧化苯乙烯。盐的作用被认为是由于在H 2 O 2水溶液中加入了饱和的Na 2 SO 4引起的。尽管底物为油相且H 2 O 2为酸性水相的双相条件,但这种添加强烈地抑制了酸不稳定的环氧产物的不希望的水解。 在Na 2 SO 4的存在下,使用钨催化的过氧化氢环氧化,可以高产率,高选择性地有效合成酸不稳定的环氧化物,例如萜烯和氧化苯乙烯。盐的作用被认为是由于在H 2 O 2水溶液中加入了饱和的Na 2 SO 4引起的。尽管底物为油相且H 2 O 2为酸性水相的双相条件,但这种添加强烈地抑制了酸不稳定的环氧产物的不希望的水解。
A versatile cobalt(II)-Schiff base catalyzed oxidation of organic substrates with dioxygen: Scope and mechanism
作者:T Punniyamurthy、Beena Bhatia、M.Madhava Reddy、Golak C Maikap、Javed Iqbal
DOI:10.1016/s0040-4020(97)00432-8
日期:1997.6
Cobalt(II) complex 1a-f derived from Schiff bases act as efficient catalysts during the oxidation of wide range of organicsubstrates(e.g. alkenes, alcohols, benzylic compounds and aliphatic hydrocarbons) with dioxygen in the presence of aliphatic aldehydes or ketones or ketoesters. EPR studies on 1a-f complexes suggest that the aliphatic carbonyl compounds promote the formation of a cobalt(III)-superoxo