Aim of this work was the development and investigation of supramolecular inhibitors of 14-3-3 proteins. Due to the dimeric nature of 14-3-3 proteins, a particular focus was thereby set on the development of bivalent ligands which simultaneously may occupy both substrate binding pockets and thus should display better binding affinities than monovalent ligands. For targeting of the phosphoserine/threonine site, the previously established phosphophenol ether motif should thereby be used. Within this work, five different, potentially bivalent-binding phosphophenol ether derivatives (Biv1 to Biv5) were prepared and investigated. All newly synthesized bivalent molecules were subsequently characterized by FP-based affinity measurements that revealed that all compounds bound the 14-3-3 proteins, however with strongly different affinities. Another aspect of this work was the development of 14-3-3 isoform-specific inhibitors. For this purpose, bioreactive phosphophenol ethers were developed, which due to their bioreactive group were envisaged to display 14-3-3σ specificity as only this isoform harbors a cysteine residue in vicinity of the phosphophenol ether binding pocket.