Recently, there has been a growing interest in the synthesis of multivalent carbohydrate assemblies due to their ability to target multiple receptors simultaneously. In the present work, a protective group strategy, based on the methodology originally developed by Crich, has been utilized for the homodimerization of olefinic carbohydrates, allowing a highly diastereoselective synthesis of some divalent structures
Efficient glycosylation of unprotected sugars using sulfamic acid: A mild eco-friendly catalyst
作者:Goutam Guchhait、Anup Kumar Misra
DOI:10.1016/j.catcom.2011.07.016
日期:2011.10
Sulfamic acid, a mild and environmentally benign catalyst has been successfully used in the Fischer glycosylation of unprotected sugars for the preparation alkyl glycosides. A diverse range of aliphatic alcohols have been used to prepare a series of alkyl glycosides in good to excellent yield. (C) 2011 Elsevier B.V. All rights reserved.
Glycosylation mediated—BAIL in aqueous solution
作者:Sébastien Delacroix、Jean-Pierre Bonnet、Matthieu Courty、Denis Postel、Albert Nguyen Van Nhien
DOI:10.1016/j.carres.2013.08.009
日期:2013.11
The use of Bronsted acid ionic liquid (BAIL) as a catalyst for the activation of unreactive and unprotected glycosyl donors has been demonstrated for the first time in aqueous solution. (c) 2013 Elsevier Ltd. All rights reserved.
Glycosylation Using Unprotected Alkynyl Donors
作者:Sreeman K. Mamidyala、M.G. Finn
DOI:10.1021/jo901857x
日期:2009.11.6
Gold(III) activation of unprotected propargyl glycosyl donors has been shown to be effective for the synthesis of saccharides. Terminal propargyl glycosides of glucose, galactose, and mannose required heating at reflux in acetonitrile with 5% AuCl(3) for reaction with various primary alcohol acceptors, the latter used in 10-fold molar excess relative to donor. Donors containing the 2-butynyl group were more reactive, giving good yields of glycoside products at lower temperatures Secondary alcohols could also be used but with diminished efficiency. The propargylic family of donors is especially convenient because they can be easily prepared on large scale by Fischer glycosylation and stored indefinitely before chemoselective activation by the catalyst.