Copper-catalyzed azide-alkyne cycloaddition precursors

The copper-catalyzed azide-alkyne cycloaddition is particularly suitable for F-labehng of sensitive biomolecules. Three different radiolabeled alkyne precursors react with azido-functionalized peptides in radiochemical yields (RCYs) of 54-99% and an overall reaction time of 30 min. The reaction is catalyzed by copper sulfate in combination with ascorbic acid or sodium ascorbate. Addition of bathophenanthroline disulfonate (Cul stabilizing agent) accelerates the cycloaddition [90]. 

Various miidazo[l,5-a]imidazoles (35), itnidazo[l,5-a] pyridines (36), and iniidazo[5,l-a]isoquinolmes (37), important ligands or precursors to pharmaceuticals," can be constructed via copper-catalyzed heterocyclization of Schiff s bases. A stepwise cycloaddition between azides and terminal alkynes is also catalyzed by copper salts in what has now been termed click chemistry, producing 1,4-disubstituted triazoles (38) in excellent yields." ... 

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