Samenvatting

The main objective of this research is to find conditions for chemical couplingreactions which are compatible with a complex biological environment. Toaccomplish this two things were needed: 1) a reaction that can be performed undermild conditions compatible with biological conditions and 2) a very sensitive analysistechnique for the detection of low substrate and product concentrations. In this studywe used the click reaction between an azide and an acetylene in the presence of acopper(I) catalyst since it tolerates many reactions conditions including biomolecules.For analysis, fluorescence spectroscopy was explored since it can detect very lowconcentrations of fluorescently active molecules in complex media. Sincefluorescence spectroscopy has never been used before to monitor catalytic reaction,also HPLC-analysis was used as a control reference.Using this strategy, we developed new click catalysis conditions using 3-azide-7-hydroxycoumarin (1) and 2-azide-N-benzyl-3-methylbutanamide (6) and we testedthree different catalysts. The click product of 1 showed much higher fluorescentemission than 1 and thus we successfully developed a fluorescence-based analysistechnique that could be used to monitor this reaction at even very low concentrations(~2 mM). In addition, we showed that this reaction depends greatly on the catalystsused, catalyst 2 being the best at these diluted conditions. Finally, we also performeda click reaction in which a biologically active product is formed at much higherconcentrations (~100 mM) using the same catalysts. Here we observed catalyst 1 wasthe best catalyst, which is probably due to concentration effects.