New synthetic approaches to sugar ureas. Access to ureido-β-cyclodextrins
摘要:
An efficient method for the preparation of urea-bridged cyclodextrins using triphosgene in the isocyanation step in an aqueous two-phase system is reported. Per-O-acetylated glycopyranosylamines and 2-amino-2-deoxy-alpha and beta-D-glucose were also transformed into the corresponding isocyanates using either an aqueous two-phase or an anhydrous dichloromethane medium, and converted in situ into ureas. An alternative method for the preparation of sugar-derived ureas consisting of desulfurization of sugar thioureas with mercury oxide is also presented. (c) 2005 Elsevier Ltd. All rights reserved.
A facile access to ureido sugars. Synthesis of urea-bridged β-cyclodextrins
作者:Inés Maya、Óscar López、Susana Maza、José G. Fernández-Bolaños、José Fuentes
DOI:10.1016/j.tetlet.2003.09.140
日期:2003.11
The preparation of a urea-bridged beta-cyclodextrin dimer and of a 6-monodeoxy-6-mono[3-(beta-D-glucopyranos-2-yl)ureido]-beta-cyclodextrin has been developed, using triphosgene as the isocyanation agent in an aqueous two-phase system. Per-O-acetylated beta-D-gluco and mannopyranosylamines and 2-amino-2-deoxy-alpha- and beta-D-glucose were also transformed into the corresponding isocyanates and converted in situ into ureas by coupling with aromatic and aliphatic amines. (C) 2003 Elsevier Ltd. All rights reserved.