Anders, T: Synthesis of new difunctional couplers and 2-acet

In the present work new coupling reagents (couplers) and N-acetylamino-2-deoxy-ß-D-glucosamine (GlcNAc) derivatives for the preparation of biofunctionalised hydrogel layers were designed. Aim was to develop a flexible tool box and a method for immobilisation of glycanes, which are of interest for glycobiology, implant coatings and diagnostic applications.On the basis of trimethylolpropane two 6-membered ring carbonate couplers were prepared, which were substituted with reactive side groups: an imidazolyl carbamate and a phenyl carbonate. Their syntheses and characterisations are described and compared to known ring carbonate couplers from the literature. These couplers have two functional groups, which are highly reactive towards amines, never the less can be selectively addressed and therefore are useful for reactions under mild reaction conditions. Starting from these couplers two orthogonal reactive couplers were synthesized, which have a 6-membered ring carbonate and a propargyl or an azide reactive side group. These orthogonal couplers have highly reactive functional groups for conversion at mild reaction conditions. In a model reaction tert-butyl- N-(3-aminopropyl) carbamate was condensed with (5-ethyl-2-oxo-1,3-dioxan-5-yl)methyl prop-2-ynylcarbamate by an addition-reaction and 2-azidoethyl 2-N-acetylamino-2-deoxy-ß- D-glucopyranose was linked by a 1,3-dipolar cycloaddition.This principle to connect two building blocks by a coupler was used for the preparation of multifunctional polymers or multifunctional surface coatings. Because of the mild reaction conditions temperature sensitive components can be used, too. Possible applications are the preparation of glycoconjugates like glycopolymers or glycoarrays. 5-Ethyl-5-((prop-2ynyloxy)methyl)-1,3-dioxan-2-one was synthesised in a 4-step-synthesis. This orthogonal reactive coupler was used to bind a biologically active N-acetylglucosamine azide to an amino-reactive microtiter plate and a microtiter