Epoxides can be cleaved in a regio- and stereoselective manner under neutral conditions with alcohols and acetic acid in the presence of catalytic amounts of decatungstocerate(IV) ion, ([CeW10O36]8−), affording the corresponding β-alkoxy and β-acetoxy alcohols in high yields. In water, ringopening of epoxides occurs with this catalyst to produce the corresponding diols in good yields.
可以在中性条件下用醇和乙酸在催化量的decatungstocerate(IV)离子([CeW 10 O 36 ] 8-)存在下,以区域和立体选择性的方式裂解环氧化合物,得到相应的β-烷氧基和β-乙酰氧基醇收率高。在水中,该催化剂会发生环氧化物的开环反应,从而以高收率生产出相应的二醇。
Bismuth(III) Chloride (BiCl<sub>3</sub>); An Efficient Catalyst for Mild, Regio- and Stereoselective Cleavage of Epoxides with Alcohols, Acetic Acid and Water
Abstract Epoxides can be cleaved in a regio- and stereoselective manner with alcohols, acetic acid and water in the presence of catalytic amounts of bismuth(III) chloride, affording the corresponding β-alkoxy and β-acetoxy alcohols and diols in high yields.
A highly efficient protocol for regioselective ring-opening of epoxides with alcohols, water, acetic acid, and acetic anhydride catalyzed by SbF<sub>3</sub>
作者:Behzad Zeynizadeh、Masumeh Gilanizadeh、Farkhondeh Mohammad Aminzadeh
DOI:10.1080/10426507.2015.1135439
日期:2016.7.2
the corresponding β-alkoxy, β-acetoxy alcohols, and 1,2-diols in high to excellent yields. This study also represents a convenient synthesis of vic-diacetates from ring-opening of epoxides with aceticanhydride.
immobilization of tungsten peroxo complex was highly temperature-dependent. The tungsten peroxo complex can dissociate and diffuse into the liquid phase at reaction temperature, resulting in a homogeneous reaction. Nevertheless, the catalytically active species was anchored on the imidazole-functionalized silica by hydrogen bonding as the temperature was lowered to 0 °C after the reaction, which thus offered a
合成了由二齿吡啶甲酸配体稳定的过氧钨配合物,然后成功地将其固定在咪唑官能化的二氧化硅上。固定化的钨基催化剂被用作由烯烃和甲醇与H2 O2一锅合成β-烷氧基醇的有效催化剂。关于催化剂评估和通过各种方法表征的结果,证明了过氧化钨配合物的固定化高度依赖于温度。过氧化钨络合物可以在反应温度下解离并扩散到液相中,从而导致均相反应。然而,随着反应后温度降低至0°C,催化活性物质通过氢键键合固定在咪唑官能化的二氧化硅上,因此,它提供了一种高效的方法来使催化剂连续循环使用。另外,在相对温和的条件下,H 2 O 2可将各种烯烃以良好的转化率和选择性转化为相应的β-烷氧基醇。
Mild and Efficient Ring Opening of Epoxides Catalyzed by Potassium Dodecatungstocobaltate(III)
作者:Shahram Tangestaninejad、Majid Moghadam、Valiollah Mirkhani、Bahram Yadollahi、S. Mohammad R. Mirmohammadi
DOI:10.1007/s00706-005-0415-7
日期:2006.2
Efficientring opening of epoxides under mild conditions is reported. Potassium dodecatungstocobaltate(III) trihydrate was used as an efficient catalyst for the alcoholysis and acetolysis of epoxides. Conversion of epoxides to thiiranes was also performed efficiently in the presence of this catalyst.