New bis-piridinium saltsHost-guest chemistry and implementation into peptide sequences

Abstract

This doctoral thesis describes the synthesis of new bis-pyridinium salts, intended for the development of new CB [7/8]-bipyridinium host-guest chemistry, and their subsequent implementation into peptide sequences. The first chapter deals with the synthesis of the vermellogens, a new family of pH-sensitive viologen analogues, which bear a hydrazone functional group replacing the direct bond between the para-substituted pyridinium molecules. In addition, the N,N'-dimethylated vermellogen showed anion recognition abilities, non-reversible electrochemical behavior and non-toxicity. Additionally, the supramolecular study was carried out with CB[7/8] macrocyclic receptors, observing a similar behavior to that previously described for paraquat, but in this case based on an acid-base response instead of the known redox capabilities of the viologens. The second chapter presents the development of a series of viologen-amino acid hybrids, designed for implementation in the solid-phase synthesis of peptides. In addition, a new methodology for obtaining vermellogen-based amino acids is presented. Finally, the ability of some of the obtained amino acids to interact with CB[7/8] receptors is discussed. In the last chapter, a new methodology for the incorporation of viologen/vermellogen derivatives at the N-terminus or within a peptide sequence was designed