Scandium cation-exchanged montmorillonite catalyzed direct C-glycosylation of a 1,3-diketone, dimedone, with unprotected sugars in aqueous solution
摘要:
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.
A Nanospherical Ordered Mesoporous Lewis Acid Polymer for the Direct Glycosylation of Unprotected and Unactivated Sugars in Water
作者:Fang Zhang、Chao Liang、Xiaotao Wu、Hexing Li
DOI:10.1002/anie.201404353
日期:2014.8.4
functionalized carbohydrate derivatives from unprotected and unactivated simple sugars in water is an outstanding challenge. Herein we describe the preparation of a novel nanosphericalorderedmesoporousLewisacidpolymer (Sc(OTf)2‐NSMP) by functionalizing the mesoporous phenol‐formaldehyde polymer framework with scandium triflate groups. In the C‐glycosylation reaction between D‐glucose and dimedone with