Highly Selective, Recyclable Epoxidation of Allylic Alcohols with Hydrogen Peroxide in Water Catalyzed by Dinuclear Peroxotungstate
作者:Keigo Kamata、Kazuya Yamaguchi、Noritaka Mizuno
DOI:10.1002/chem.200400352
日期:2004.10.4
of oxygen to the carbon-carbon double bond, and the regeneration of the dinuclear peroxotungstate with hydrogenperoxide is proposed. The reaction rate shows first-order dependence on the concentrations of allylic alcohol and dinuclear peroxotungstate and zero-order dependence on the concentration of hydrogenperoxide. These results, the kinetic data, the comparison of the catalytic rates with those
双核过氧钨酸钾K2 [[W(= O)(O2)2(H2O) ] 2(mu-O)] 2 H 2 O(I)。该催化剂易于回收,同时保持其催化性能。提出了催化反应机理,包括交换水配体以形成钨醇盐物种,然后将氧插入碳-碳双键,并用过氧化氢再生双核过氧钨酸盐。反应速率显示出对烯丙基醇和双核过氧钨酸盐的浓度的一级依赖性,而对过氧化氢的浓度则呈零级依赖性。这些结果,动力学数据,
Diastereoselective epoxidation of olefins by organo sulfonic peracids, II
作者:R. Kluge、M. Schulz、S. Liebsch
DOI:10.1016/0040-4020(95)01128-5
日期:1996.2
have investigated the behaviour of sulfonic peracids 2in situ generated towards olefins 7a,7b,9,11,14,16,18, allylic and homoallylic alcohols 20,22,24,26,28,30,33 and α,β-unsaturated ketones 35,37,39. Generally, the epoxidation proceeds in a peracid-like manner with greater diastereoselectivity than those by common oxidants. In particular, the epoxidation of Δ4 3-ketosteroids 39a-i led to 4α,5α-epoxides
Stereoselective expoxidation of allylic and homoallylic alcohols with 30% hydrogen peroxide catalyzed by tungstic acid in buffered media
作者:Denis Prat、Bernard Delpech、Robert Lett
DOI:10.1016/s0040-4039(00)84080-0
日期:1986.1
The aqueous tungstic acid-catalyzed hydrogenperoxideepoxidation of allylicalcohols affords the same major diastereoisomer as the VO(acac)2/tBuOOH system with quite comparable stereoselectivities. In contrast, epoxidation of homoallylic alcohols appears to be much less stereoselective.
A New Highly Selective Method for the Catalytic Epoxidation of Chiral Allylic Alcohols by Sandwich-Type Polyoxometalates with Hydrogen Peroxide
作者:Rui Zhang、Waldemar Adam、Paul L. Alsters、Ronny Neumann、Chantu R. Saha-Möller、Dorit Sloboda-Rozner
DOI:10.1055/s-2002-35570
日期:——
persistent sandwich-type polyoxometalates, namely [WZnM 2 (ZnW 9 O 3 4 ) 2 ] q - [M = Mn(II), Ru(III), Fe(III), Zn(II)], catalyze chemoselectively, diastereoselectively and regioselectively the epoxidation of chiral allylic alcohols with 30% hydrogen peroxide through a tungsten peroxo species, in which the allylic alcohol is coordinated as alcoholate (template effect).
The title complex oxidizes primary and secondary alcohols to the corresponding carbonyl compounds. Stereoselective epoxidation of allylic alcohols is also described.