Preparation, characterizations, and application of (MWCNTs)-COOH/Fe<sub>3</sub>O<sub>4</sub>-CaO hybrid as an effective magnetic catalyst for direct C-glycosylation reactions
Abstract Modification of acid-functionalized multiwalled carbon nanotubes (MWCNTs)-COOH with Fe3O4-CaO nanoparticles using FeSO4 and eggshell, produced an efficient magnetic catalyst for the synthesis of some C-glycosides. The condensation of dimedone with unprotected sugars in ethanol in the presence of a catalytic amount of (MWCNTs)-COOH/Fe3O4-CaO gave 3,4,5,6,7,9-hexahydro-1H-xanthene-1,8 (2H)-dione
摘要 使用 FeSO 4和蛋壳对酸功能化多壁碳纳米管 (MWCNT)-COOH 和 Fe 3 O 4 -CaO 纳米粒子进行改性,产生了一种用于合成某些 C-糖苷的高效磁性催化剂。在催化量的 (MWCNTs)-COOH/Fe 3 O 4 -CaO存在下,双甲酮与未保护的糖在乙醇中缩合,得到 3,4,5,6,7,9-六氢-1H-呫吨-1, 8 (2H)-二酮衍生物,收率高。通过 CHN 分析、NMR 和 FTIR 光谱鉴定产物。反之,Fe 3 O 4的合成-CaO 纳米颗粒及其在 (MWCNT)-COOH 表面的共轭已通过 FTIR、扫描电子显微镜、透射电子显微镜、X 射线衍射和能量色散 X 射线光谱得到证实。
Scandium cation-exchanged montmorillonite catalyzed direct C-glycosylation of a 1,3-diketone, dimedone, with unprotected sugars in aqueous solution
作者:Shingo Sato、Yuzo Naito、Kazuyori Aoki
DOI:10.1016/j.carres.2007.01.013
日期:2007.5
The condensation of dimedone with unprotected sugars in aqueous solution in the presence of a catalytic amount of Sc3+- montmorillonite (Sc3+-mont) gave 9-hydroxyalkyl-3,3,6,6,-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-diones in good yields, while the use of Sc(OTf)(3) instead of SC3+-mont gave the hydroxyalkyl-6,7-dihydrobenzofuran-4(5H)-one derivatives in good yields. Furthermore, Sc3+-mont could be recycled without inactivation. (c) 2007 Elsevier Ltd. All rights reserved.