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,
Chemoselective C−H Oxidation of Alcohols to Carbonyl Compounds with Iodosobenzene Catalyzed by (Salen)chromium Complex
作者:Waldemar Adam、Feyissa Gadissa Gelalcha、Chantu R. Saha-Möller、Veit R. Stegmann
DOI:10.1021/jo9913457
日期:2000.4.1
secondary alcohols with benzylically and allylically activated C-H bonds are chemoselectively oxidized to the corresponding carbonylcompounds by the (salen)Cr(III) complex I as the catalyst and iodosobenzene as the oxygen source; the oxidizing species is the Cr(V) oxo complex. Allylicalcohols with fully substituted double bonds give appreciable amounts of epoxides besides the C-H oxidation products
Chiral Hydroperoxides as Oxygen Source in the Catalytic Stereoselective Epoxidation of Allylic Alcohols by Sandwich-Type Polyoxometalates: Control of Enantioselectivity through a Metal-Coordinated Template
作者:Waldemar Adam、Paul L. Alsters、Ronny Neumann、Chantu R. Saha-Möller、Dieter Seebach、Albert K. Beck、Rui Zhang
DOI:10.1021/jo034923z
日期:2003.10.1
The epoxidation of allylic alcohols is shown to be efficiently and selectively catalyzed by the oxidatively resistant sandwich-type polyoxometalates, POMs, namely [WZnM(2)(ZnW(9)O(34))(2)](q)(-) [M = OV(IV), Mn(II), Ru(III), Fe(III), Pd(II), Pt(II), Zn(II); q = 10-12], with organic hydroperoxides as oxygen source. Conspicuous is the fact that the nature of the transition metal M in the central ring
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).
Highly stereoselective synthesis of -α, β-epoxy alcohols by the reduction of α, β-epoxy ketones with zinc borohydride
作者:Tadashi Nakata、Tadasu Tanaka、Takeshi Oishi
DOI:10.1016/s0040-4039(01)83023-9
日期:1981.1
-α, β-epoxy alcohols were prepared in high stereoselectivity by zincborohydridereduction of the corresponding α, β-epoxy ketones regardless of the substituents on the epoxide ring.