Application of Sulfonic Acid Functionalised Hybrid Silicas Obtained by Oxidative Cleavage of Tetrasulfide Bridges as Catalysts in Esterification Reactions
作者:María Isabel López、Dolores Esquivel、César Jiménez-Sanchidrián、Francisco José Romero-Salguero
DOI:10.1002/cctc.201200509
日期:2013.4
sulfonic acid functionalised materials were used as catalysts in the esterification of acetic acid with ethanol, and they exhibited a comparable or very similar activity to that of Amberlyst‐15. Several mesoporous and microporous hybridmaterials were selected and compared to this commercial resin in the transformation of more hydrophobic substrates. Some of these hybridmaterials were especially attractive
在酸性条件下,在存在Brij-76作为结构的条件下,在酸性条件下,双[3-(三乙氧基甲硅烷基)丙基]四硫化物与原硅酸四乙酯或1,4-双(三乙氧基甲硅烷基)苯之间的共缩合反应可合成具有四硫键的杂化材料。指导剂。通过H 2 O 2处理对它们进行了后修饰持续3小时或24小时。随着合成混合物中S含量的增加,观察到所得材料中介观结构的逐渐损失。因此,只有那些具有最低四硫化物含量的样品才能被认为是周期性的介孔有机硅。这种作用在氧化时甚至更加明显。氧化后的材料表现出相当大的酸度,尤其是两种前体的酸度大致相等。所有磺酸官能化的材料均用作乙酸与乙醇的酯化反应的催化剂,它们表现出与Amberlyst-15相当或非常相似的活性。选择了几种中孔和微孔杂化材料,并将其与这种商业树脂进行了比较疏水的底物转化。
Schlenk,W., Justus Liebigs Annalen der Chemie, 1973, p. 1179 - 1194
作者:Schlenk,W.
DOI:——
日期:——
Novel distannoxane-catalyzed transesterification and a new entry to α, β-unsaturated carboxylic acids
transesterification reaction has been developed which affords various types of esters under very mild conditions. The reaction was applied to the stereo- and regioselective synthesis of trisubstituted α,β-unsaturatedcarboxylicacids.