The Synthesis and Structure of Linear and Dendritic Thiourea‐Linked Glycooligomers

Abstract

AbstractAn efficient strategy to produce unnatural glycooligomers containing thiourea intersaccharide bridges has been developed. The presence of the thiourea groups in these oligomers should promote the association with polyphosphates, including nucleic acids, due to the hydrogen‐bonding capabilities of the thioureas. Moreover, glycooligomers built from thiourea groups should form complex secondary and tertiary structures due to the interplay of hydrogen bonding and rotational restriction at the bonds adjacent to thiocarbonyl groups. Herein, the preparation and conformational properties of both linear and dendritic architectures are described. This synthetic method relies on the coupling of peracetylated azidoglycosyl isothiocyanates and fully unprotected amine‐functionalised growing oligomers. Deacetylation of the hemiacetylated thiourea adduct and reduction of the azido groups allow entry into a new coupling cycle. The procedure is quite general, should be easily extended to molecular diversity‐oriented and solid‐phase approaches and will allow the investigation of intermolecular interactions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)